diff --git a/migrations/2_deploy_contracts.js b/migrations/2_deploy_contracts.js
new file mode 100644
index 0000000..e514d24
--- /dev/null
+++ b/migrations/2_deploy_contracts.js
@@ -0,0 +1,5 @@
+const Color = artifacts.require("Color");
+
+module.exports = function(deployer) {
+  deployer.deploy(Color);
+};
diff --git a/package-lock.json b/package-lock.json
index 22e6901..1ad85bb 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -1120,6 +1120,11 @@
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@@ -1143,6 +1148,104 @@
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@@ -3834,7 +3937,6 @@
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@@ -18805,15 +18379,6 @@
         "ajv-keywords": "3.4.1"
       }
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@@ -18824,7 +18389,6 @@
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         "scryptsy": "1.2.1"
       }
     },
@@ -19289,6 +18853,11 @@
         }
       }
     },
+    "solidity-parser-antlr": {
+      "version": "0.4.11",
+      "resolved": "https://registry.npmjs.org/solidity-parser-antlr/-/solidity-parser-antlr-0.4.11.tgz",
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+    },
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@@ -20200,6 +19769,18 @@
         "solc": "0.5.0"
       }
     },
+    "truffle-flattener": {
+      "version": "1.4.2",
+      "resolved": "https://registry.npmjs.org/truffle-flattener/-/truffle-flattener-1.4.2.tgz",
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+      "requires": {
+        "@resolver-engine/imports-fs": "0.2.2",
+        "find-up": "2.1.0",
+        "mkdirp": "0.5.1",
+        "solidity-parser-antlr": "0.4.11",
+        "tsort": "0.0.1"
+      }
+    },
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@@ -20210,6 +19791,11 @@
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diff --git a/package.json b/package.json
index 6c1ffc5..21d0785 100644
--- a/package.json
+++ b/package.json
@@ -4,6 +4,7 @@
   "description": "An Ethereum Marketplace",
   "author": "gregory@dappuniversity.com",
   "dependencies": {
+    "@openzeppelin/contracts": "^2.3.0",
     "babel-polyfill": "6.26.0",
     "babel-preset-env": "1.7.0",
     "babel-preset-es2015": "6.24.1",
@@ -19,6 +20,7 @@
     "react-dom": "16.8.4",
     "react-scripts": "2.1.3",
     "truffle": "5.0.5",
+    "truffle-flattener": "^1.4.2",
     "web3": "1.0.0-beta.55"
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diff --git a/src/abis/Address.json b/src/abis/Address.json
new file mode 100644
index 0000000..d75fe88
--- /dev/null
+++ b/src/abis/Address.json
@@ -0,0 +1,37448 @@
+{
+  "contractName": "Address",
+  "abi": [],
+  "bytecode": "0x604c602c600b82828239805160001a60731460008114601c57601e565bfe5b5030600052607381538281f3fe73000000000000000000000000000000000000000030146080604052600080fdfea165627a7a7230582093b362921bf95d5d37b95b344fda3ce8ff9f9cf13718c7cb42212d92a99cf1890029",
+  "deployedBytecode": "0x73000000000000000000000000000000000000000030146080604052600080fdfea165627a7a7230582093b362921bf95d5d37b95b344fda3ce8ff9f9cf13718c7cb42212d92a99cf1890029",
+  "sourceMap": "7788:863:1:-;;132:2:-1;166:7;155:9;146:7;137:37;252:7;246:14;243:1;238:23;232:4;229:33;270:1;265:20;;;;222:63;;265:20;274:9;222:63;;298:9;295:1;288:20;328:4;319:7;311:22;352:7;343;336:24",
+  "deployedSourceMap": "7788:863:1:-;;;;;;;;",
+  "source": "\n// File: @openzeppelin/contracts/introspection/IERC165.sol\n\npragma solidity ^0.5.0;\n\n/**\n * @dev Interface of the ERC165 standard, as defined in the\n * [EIP](https://eips.ethereum.org/EIPS/eip-165).\n *\n * Implementers can declare support of contract interfaces, which can then be\n * queried by others (`ERC165Checker`).\n *\n * For an implementation, see `ERC165`.\n */\ninterface IERC165 {\n    /**\n     * @dev Returns true if this contract implements the interface defined by\n     * `interfaceId`. See the corresponding\n     * [EIP section](https://eips.ethereum.org/EIPS/eip-165#how-interfaces-are-identified)\n     * to learn more about how these ids are created.\n     *\n     * This function call must use less than 30 000 gas.\n     */\n    function supportsInterface(bytes4 interfaceId) external view returns (bool);\n}\n\n// File: @openzeppelin/contracts/token/ERC721/IERC721.sol\n\npragma solidity ^0.5.0;\n\n\n/**\n * @dev Required interface of an ERC721 compliant contract.\n */\ncontract IERC721 is IERC165 {\n    event Transfer(address indexed from, address indexed to, uint256 indexed tokenId);\n    event Approval(address indexed owner, address indexed approved, uint256 indexed tokenId);\n    event ApprovalForAll(address indexed owner, address indexed operator, bool approved);\n\n    /**\n     * @dev Returns the number of NFTs in `owner`'s account.\n     */\n    function balanceOf(address owner) public view returns (uint256 balance);\n\n    /**\n     * @dev Returns the owner of the NFT specified by `tokenId`.\n     */\n    function ownerOf(uint256 tokenId) public view returns (address owner);\n\n    /**\n     * @dev Transfers a specific NFT (`tokenId`) from one account (`from`) to\n     * another (`to`).\n     *\n     * \n     *\n     * Requirements:\n     * - `from`, `to` cannot be zero.\n     * - `tokenId` must be owned by `from`.\n     * - If the caller is not `from`, it must be have been allowed to move this\n     * NFT by either `approve` or `setApproveForAll`.\n     */\n    function safeTransferFrom(address from, address to, uint256 tokenId) public;\n    /**\n     * @dev Transfers a specific NFT (`tokenId`) from one account (`from`) to\n     * another (`to`).\n     *\n     * Requirements:\n     * - If the caller is not `from`, it must be approved to move this NFT by\n     * either `approve` or `setApproveForAll`.\n     */\n    function transferFrom(address from, address to, uint256 tokenId) public;\n    function approve(address to, uint256 tokenId) public;\n    function getApproved(uint256 tokenId) public view returns (address operator);\n\n    function setApprovalForAll(address operator, bool _approved) public;\n    function isApprovedForAll(address owner, address operator) public view returns (bool);\n\n\n    function safeTransferFrom(address from, address to, uint256 tokenId, bytes memory data) public;\n}\n\n// File: @openzeppelin/contracts/token/ERC721/IERC721Receiver.sol\n\npragma solidity ^0.5.0;\n\n/**\n * @title ERC721 token receiver interface\n * @dev Interface for any contract that wants to support safeTransfers\n * from ERC721 asset contracts.\n */\ncontract IERC721Receiver {\n    /**\n     * @notice Handle the receipt of an NFT\n     * @dev The ERC721 smart contract calls this function on the recipient\n     * after a `safeTransfer`. This function MUST return the function selector,\n     * otherwise the caller will revert the transaction. The selector to be\n     * returned can be obtained as `this.onERC721Received.selector`. This\n     * function MAY throw to revert and reject the transfer.\n     * Note: the ERC721 contract address is always the message sender.\n     * @param operator The address which called `safeTransferFrom` function\n     * @param from The address which previously owned the token\n     * @param tokenId The NFT identifier which is being transferred\n     * @param data Additional data with no specified format\n     * @return bytes4 `bytes4(keccak256(\"onERC721Received(address,address,uint256,bytes)\"))`\n     */\n    function onERC721Received(address operator, address from, uint256 tokenId, bytes memory data)\n    public returns (bytes4);\n}\n\n// File: @openzeppelin/contracts/math/SafeMath.sol\n\npragma solidity ^0.5.0;\n\n/**\n * @dev Wrappers over Solidity's arithmetic operations with added overflow\n * checks.\n *\n * Arithmetic operations in Solidity wrap on overflow. This can easily result\n * in bugs, because programmers usually assume that an overflow raises an\n * error, which is the standard behavior in high level programming languages.\n * `SafeMath` restores this intuition by reverting the transaction when an\n * operation overflows.\n *\n * Using this library instead of the unchecked operations eliminates an entire\n * class of bugs, so it's recommended to use it always.\n */\nlibrary SafeMath {\n    /**\n     * @dev Returns the addition of two unsigned integers, reverting on\n     * overflow.\n     *\n     * Counterpart to Solidity's `+` operator.\n     *\n     * Requirements:\n     * - Addition cannot overflow.\n     */\n    function add(uint256 a, uint256 b) internal pure returns (uint256) {\n        uint256 c = a + b;\n        require(c >= a, \"SafeMath: addition overflow\");\n\n        return c;\n    }\n\n    /**\n     * @dev Returns the subtraction of two unsigned integers, reverting on\n     * overflow (when the result is negative).\n     *\n     * Counterpart to Solidity's `-` operator.\n     *\n     * Requirements:\n     * - Subtraction cannot overflow.\n     */\n    function sub(uint256 a, uint256 b) internal pure returns (uint256) {\n        require(b <= a, \"SafeMath: subtraction overflow\");\n        uint256 c = a - b;\n\n        return c;\n    }\n\n    /**\n     * @dev Returns the multiplication of two unsigned integers, reverting on\n     * overflow.\n     *\n     * Counterpart to Solidity's `*` operator.\n     *\n     * Requirements:\n     * - Multiplication cannot overflow.\n     */\n    function mul(uint256 a, uint256 b) internal pure returns (uint256) {\n        // Gas optimization: this is cheaper than requiring 'a' not being zero, but the\n        // benefit is lost if 'b' is also tested.\n        // See: https://github.com/OpenZeppelin/openzeppelin-contracts/pull/522\n        if (a == 0) {\n            return 0;\n        }\n\n        uint256 c = a * b;\n        require(c / a == b, \"SafeMath: multiplication overflow\");\n\n        return c;\n    }\n\n    /**\n     * @dev Returns the integer division of two unsigned integers. Reverts on\n     * division by zero. The result is rounded towards zero.\n     *\n     * Counterpart to Solidity's `/` operator. Note: this function uses a\n     * `revert` opcode (which leaves remaining gas untouched) while Solidity\n     * uses an invalid opcode to revert (consuming all remaining gas).\n     *\n     * Requirements:\n     * - The divisor cannot be zero.\n     */\n    function div(uint256 a, uint256 b) internal pure returns (uint256) {\n        // Solidity only automatically asserts when dividing by 0\n        require(b > 0, \"SafeMath: division by zero\");\n        uint256 c = a / b;\n        // assert(a == b * c + a % b); // There is no case in which this doesn't hold\n\n        return c;\n    }\n\n    /**\n     * @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo),\n     * Reverts when dividing by zero.\n     *\n     * Counterpart to Solidity's `%` operator. This function uses a `revert`\n     * opcode (which leaves remaining gas untouched) while Solidity uses an\n     * invalid opcode to revert (consuming all remaining gas).\n     *\n     * Requirements:\n     * - The divisor cannot be zero.\n     */\n    function mod(uint256 a, uint256 b) internal pure returns (uint256) {\n        require(b != 0, \"SafeMath: modulo by zero\");\n        return a % b;\n    }\n}\n\n// File: @openzeppelin/contracts/utils/Address.sol\n\npragma solidity ^0.5.0;\n\n/**\n * @dev Collection of functions related to the address type,\n */\nlibrary Address {\n    /**\n     * @dev Returns true if `account` is a contract.\n     *\n     * This test is non-exhaustive, and there may be false-negatives: during the\n     * execution of a contract's constructor, its address will be reported as\n     * not containing a contract.\n     *\n     * > It is unsafe to assume that an address for which this function returns\n     * false is an externally-owned account (EOA) and not a contract.\n     */\n    function isContract(address account) internal view returns (bool) {\n        // This method relies in extcodesize, which returns 0 for contracts in\n        // construction, since the code is only stored at the end of the\n        // constructor execution.\n\n        uint256 size;\n        // solhint-disable-next-line no-inline-assembly\n        assembly { size := extcodesize(account) }\n        return size > 0;\n    }\n}\n\n// File: @openzeppelin/contracts/drafts/Counters.sol\n\npragma solidity ^0.5.0;\n\n\n/**\n * @title Counters\n * @author Matt Condon (@shrugs)\n * @dev Provides counters that can only be incremented or decremented by one. This can be used e.g. to track the number\n * of elements in a mapping, issuing ERC721 ids, or counting request ids.\n *\n * Include with `using Counters for Counters.Counter;`\n * Since it is not possible to overflow a 256 bit integer with increments of one, `increment` can skip the SafeMath\n * overflow check, thereby saving gas. This does assume however correct usage, in that the underlying `_value` is never\n * directly accessed.\n */\nlibrary Counters {\n    using SafeMath for uint256;\n\n    struct Counter {\n        // This variable should never be directly accessed by users of the library: interactions must be restricted to\n        // the library's function. As of Solidity v0.5.2, this cannot be enforced, though there is a proposal to add\n        // this feature: see https://github.com/ethereum/solidity/issues/4637\n        uint256 _value; // default: 0\n    }\n\n    function current(Counter storage counter) internal view returns (uint256) {\n        return counter._value;\n    }\n\n    function increment(Counter storage counter) internal {\n        counter._value += 1;\n    }\n\n    function decrement(Counter storage counter) internal {\n        counter._value = counter._value.sub(1);\n    }\n}\n\n// File: @openzeppelin/contracts/introspection/ERC165.sol\n\npragma solidity ^0.5.0;\n\n\n/**\n * @dev Implementation of the `IERC165` interface.\n *\n * Contracts may inherit from this and call `_registerInterface` to declare\n * their support of an interface.\n */\ncontract ERC165 is IERC165 {\n    /*\n     * bytes4(keccak256('supportsInterface(bytes4)')) == 0x01ffc9a7\n     */\n    bytes4 private constant _INTERFACE_ID_ERC165 = 0x01ffc9a7;\n\n    /**\n     * @dev Mapping of interface ids to whether or not it's supported.\n     */\n    mapping(bytes4 => bool) private _supportedInterfaces;\n\n    constructor () internal {\n        // Derived contracts need only register support for their own interfaces,\n        // we register support for ERC165 itself here\n        _registerInterface(_INTERFACE_ID_ERC165);\n    }\n\n    /**\n     * @dev See `IERC165.supportsInterface`.\n     *\n     * Time complexity O(1), guaranteed to always use less than 30 000 gas.\n     */\n    function supportsInterface(bytes4 interfaceId) external view returns (bool) {\n        return _supportedInterfaces[interfaceId];\n    }\n\n    /**\n     * @dev Registers the contract as an implementer of the interface defined by\n     * `interfaceId`. Support of the actual ERC165 interface is automatic and\n     * registering its interface id is not required.\n     *\n     * See `IERC165.supportsInterface`.\n     *\n     * Requirements:\n     *\n     * - `interfaceId` cannot be the ERC165 invalid interface (`0xffffffff`).\n     */\n    function _registerInterface(bytes4 interfaceId) internal {\n        require(interfaceId != 0xffffffff, \"ERC165: invalid interface id\");\n        _supportedInterfaces[interfaceId] = true;\n    }\n}\n\n// File: @openzeppelin/contracts/token/ERC721/ERC721.sol\n\npragma solidity ^0.5.0;\n\n\n\n\n\n\n\n/**\n * @title ERC721 Non-Fungible Token Standard basic implementation\n * @dev see https://eips.ethereum.org/EIPS/eip-721\n */\ncontract ERC721 is ERC165, IERC721 {\n    using SafeMath for uint256;\n    using Address for address;\n    using Counters for Counters.Counter;\n\n    // Equals to `bytes4(keccak256(\"onERC721Received(address,address,uint256,bytes)\"))`\n    // which can be also obtained as `IERC721Receiver(0).onERC721Received.selector`\n    bytes4 private constant _ERC721_RECEIVED = 0x150b7a02;\n\n    // Mapping from token ID to owner\n    mapping (uint256 => address) private _tokenOwner;\n\n    // Mapping from token ID to approved address\n    mapping (uint256 => address) private _tokenApprovals;\n\n    // Mapping from owner to number of owned token\n    mapping (address => Counters.Counter) private _ownedTokensCount;\n\n    // Mapping from owner to operator approvals\n    mapping (address => mapping (address => bool)) private _operatorApprovals;\n\n    /*\n     *     bytes4(keccak256('balanceOf(address)')) == 0x70a08231\n     *     bytes4(keccak256('ownerOf(uint256)')) == 0x6352211e\n     *     bytes4(keccak256('approve(address,uint256)')) == 0x095ea7b3\n     *     bytes4(keccak256('getApproved(uint256)')) == 0x081812fc\n     *     bytes4(keccak256('setApprovalForAll(address,bool)')) == 0xa22cb465\n     *     bytes4(keccak256('isApprovedForAll(address,address)')) == 0xe985e9c\n     *     bytes4(keccak256('transferFrom(address,address,uint256)')) == 0x23b872dd\n     *     bytes4(keccak256('safeTransferFrom(address,address,uint256)')) == 0x42842e0e\n     *     bytes4(keccak256('safeTransferFrom(address,address,uint256,bytes)')) == 0xb88d4fde\n     *\n     *     => 0x70a08231 ^ 0x6352211e ^ 0x095ea7b3 ^ 0x081812fc ^\n     *        0xa22cb465 ^ 0xe985e9c ^ 0x23b872dd ^ 0x42842e0e ^ 0xb88d4fde == 0x80ac58cd\n     */\n    bytes4 private constant _INTERFACE_ID_ERC721 = 0x80ac58cd;\n\n    constructor () public {\n        // register the supported interfaces to conform to ERC721 via ERC165\n        _registerInterface(_INTERFACE_ID_ERC721);\n    }\n\n    /**\n     * @dev Gets the balance of the specified address.\n     * @param owner address to query the balance of\n     * @return uint256 representing the amount owned by the passed address\n     */\n    function balanceOf(address owner) public view returns (uint256) {\n        require(owner != address(0), \"ERC721: balance query for the zero address\");\n\n        return _ownedTokensCount[owner].current();\n    }\n\n    /**\n     * @dev Gets the owner of the specified token ID.\n     * @param tokenId uint256 ID of the token to query the owner of\n     * @return address currently marked as the owner of the given token ID\n     */\n    function ownerOf(uint256 tokenId) public view returns (address) {\n        address owner = _tokenOwner[tokenId];\n        require(owner != address(0), \"ERC721: owner query for nonexistent token\");\n\n        return owner;\n    }\n\n    /**\n     * @dev Approves another address to transfer the given token ID\n     * The zero address indicates there is no approved address.\n     * There can only be one approved address per token at a given time.\n     * Can only be called by the token owner or an approved operator.\n     * @param to address to be approved for the given token ID\n     * @param tokenId uint256 ID of the token to be approved\n     */\n    function approve(address to, uint256 tokenId) public {\n        address owner = ownerOf(tokenId);\n        require(to != owner, \"ERC721: approval to current owner\");\n\n        require(msg.sender == owner || isApprovedForAll(owner, msg.sender),\n            \"ERC721: approve caller is not owner nor approved for all\"\n        );\n\n        _tokenApprovals[tokenId] = to;\n        emit Approval(owner, to, tokenId);\n    }\n\n    /**\n     * @dev Gets the approved address for a token ID, or zero if no address set\n     * Reverts if the token ID does not exist.\n     * @param tokenId uint256 ID of the token to query the approval of\n     * @return address currently approved for the given token ID\n     */\n    function getApproved(uint256 tokenId) public view returns (address) {\n        require(_exists(tokenId), \"ERC721: approved query for nonexistent token\");\n\n        return _tokenApprovals[tokenId];\n    }\n\n    /**\n     * @dev Sets or unsets the approval of a given operator\n     * An operator is allowed to transfer all tokens of the sender on their behalf.\n     * @param to operator address to set the approval\n     * @param approved representing the status of the approval to be set\n     */\n    function setApprovalForAll(address to, bool approved) public {\n        require(to != msg.sender, \"ERC721: approve to caller\");\n\n        _operatorApprovals[msg.sender][to] = approved;\n        emit ApprovalForAll(msg.sender, to, approved);\n    }\n\n    /**\n     * @dev Tells whether an operator is approved by a given owner.\n     * @param owner owner address which you want to query the approval of\n     * @param operator operator address which you want to query the approval of\n     * @return bool whether the given operator is approved by the given owner\n     */\n    function isApprovedForAll(address owner, address operator) public view returns (bool) {\n        return _operatorApprovals[owner][operator];\n    }\n\n    /**\n     * @dev Transfers the ownership of a given token ID to another address.\n     * Usage of this method is discouraged, use `safeTransferFrom` whenever possible.\n     * Requires the msg.sender to be the owner, approved, or operator.\n     * @param from current owner of the token\n     * @param to address to receive the ownership of the given token ID\n     * @param tokenId uint256 ID of the token to be transferred\n     */\n    function transferFrom(address from, address to, uint256 tokenId) public {\n        //solhint-disable-next-line max-line-length\n        require(_isApprovedOrOwner(msg.sender, tokenId), \"ERC721: transfer caller is not owner nor approved\");\n\n        _transferFrom(from, to, tokenId);\n    }\n\n    /**\n     * @dev Safely transfers the ownership of a given token ID to another address\n     * If the target address is a contract, it must implement `onERC721Received`,\n     * which is called upon a safe transfer, and return the magic value\n     * `bytes4(keccak256(\"onERC721Received(address,address,uint256,bytes)\"))`; otherwise,\n     * the transfer is reverted.\n     * Requires the msg.sender to be the owner, approved, or operator\n     * @param from current owner of the token\n     * @param to address to receive the ownership of the given token ID\n     * @param tokenId uint256 ID of the token to be transferred\n     */\n    function safeTransferFrom(address from, address to, uint256 tokenId) public {\n        safeTransferFrom(from, to, tokenId, \"\");\n    }\n\n    /**\n     * @dev Safely transfers the ownership of a given token ID to another address\n     * If the target address is a contract, it must implement `onERC721Received`,\n     * which is called upon a safe transfer, and return the magic value\n     * `bytes4(keccak256(\"onERC721Received(address,address,uint256,bytes)\"))`; otherwise,\n     * the transfer is reverted.\n     * Requires the msg.sender to be the owner, approved, or operator\n     * @param from current owner of the token\n     * @param to address to receive the ownership of the given token ID\n     * @param tokenId uint256 ID of the token to be transferred\n     * @param _data bytes data to send along with a safe transfer check\n     */\n    function safeTransferFrom(address from, address to, uint256 tokenId, bytes memory _data) public {\n        transferFrom(from, to, tokenId);\n        require(_checkOnERC721Received(from, to, tokenId, _data), \"ERC721: transfer to non ERC721Receiver implementer\");\n    }\n\n    /**\n     * @dev Returns whether the specified token exists.\n     * @param tokenId uint256 ID of the token to query the existence of\n     * @return bool whether the token exists\n     */\n    function _exists(uint256 tokenId) internal view returns (bool) {\n        address owner = _tokenOwner[tokenId];\n        return owner != address(0);\n    }\n\n    /**\n     * @dev Returns whether the given spender can transfer a given token ID.\n     * @param spender address of the spender to query\n     * @param tokenId uint256 ID of the token to be transferred\n     * @return bool whether the msg.sender is approved for the given token ID,\n     * is an operator of the owner, or is the owner of the token\n     */\n    function _isApprovedOrOwner(address spender, uint256 tokenId) internal view returns (bool) {\n        require(_exists(tokenId), \"ERC721: operator query for nonexistent token\");\n        address owner = ownerOf(tokenId);\n        return (spender == owner || getApproved(tokenId) == spender || isApprovedForAll(owner, spender));\n    }\n\n    /**\n     * @dev Internal function to mint a new token.\n     * Reverts if the given token ID already exists.\n     * @param to The address that will own the minted token\n     * @param tokenId uint256 ID of the token to be minted\n     */\n    function _mint(address to, uint256 tokenId) internal {\n        require(to != address(0), \"ERC721: mint to the zero address\");\n        require(!_exists(tokenId), \"ERC721: token already minted\");\n\n        _tokenOwner[tokenId] = to;\n        _ownedTokensCount[to].increment();\n\n        emit Transfer(address(0), to, tokenId);\n    }\n\n    /**\n     * @dev Internal function to burn a specific token.\n     * Reverts if the token does not exist.\n     * Deprecated, use _burn(uint256) instead.\n     * @param owner owner of the token to burn\n     * @param tokenId uint256 ID of the token being burned\n     */\n    function _burn(address owner, uint256 tokenId) internal {\n        require(ownerOf(tokenId) == owner, \"ERC721: burn of token that is not own\");\n\n        _clearApproval(tokenId);\n\n        _ownedTokensCount[owner].decrement();\n        _tokenOwner[tokenId] = address(0);\n\n        emit Transfer(owner, address(0), tokenId);\n    }\n\n    /**\n     * @dev Internal function to burn a specific token.\n     * Reverts if the token does not exist.\n     * @param tokenId uint256 ID of the token being burned\n     */\n    function _burn(uint256 tokenId) internal {\n        _burn(ownerOf(tokenId), tokenId);\n    }\n\n    /**\n     * @dev Internal function to transfer ownership of a given token ID to another address.\n     * As opposed to transferFrom, this imposes no restrictions on msg.sender.\n     * @param from current owner of the token\n     * @param to address to receive the ownership of the given token ID\n     * @param tokenId uint256 ID of the token to be transferred\n     */\n    function _transferFrom(address from, address to, uint256 tokenId) internal {\n        require(ownerOf(tokenId) == from, \"ERC721: transfer of token that is not own\");\n        require(to != address(0), \"ERC721: transfer to the zero address\");\n\n        _clearApproval(tokenId);\n\n        _ownedTokensCount[from].decrement();\n        _ownedTokensCount[to].increment();\n\n        _tokenOwner[tokenId] = to;\n\n        emit Transfer(from, to, tokenId);\n    }\n\n    /**\n     * @dev Internal function to invoke `onERC721Received` on a target address.\n     * The call is not executed if the target address is not a contract.\n     *\n     * This function is deprecated.\n     * @param from address representing the previous owner of the given token ID\n     * @param to target address that will receive the tokens\n     * @param tokenId uint256 ID of the token to be transferred\n     * @param _data bytes optional data to send along with the call\n     * @return bool whether the call correctly returned the expected magic value\n     */\n    function _checkOnERC721Received(address from, address to, uint256 tokenId, bytes memory _data)\n        internal returns (bool)\n    {\n        if (!to.isContract()) {\n            return true;\n        }\n\n        bytes4 retval = IERC721Receiver(to).onERC721Received(msg.sender, from, tokenId, _data);\n        return (retval == _ERC721_RECEIVED);\n    }\n\n    /**\n     * @dev Private function to clear current approval of a given token ID.\n     * @param tokenId uint256 ID of the token to be transferred\n     */\n    function _clearApproval(uint256 tokenId) private {\n        if (_tokenApprovals[tokenId] != address(0)) {\n            _tokenApprovals[tokenId] = address(0);\n        }\n    }\n}\n\n// File: @openzeppelin/contracts/token/ERC721/IERC721Enumerable.sol\n\npragma solidity ^0.5.0;\n\n\n/**\n * @title ERC-721 Non-Fungible Token Standard, optional enumeration extension\n * @dev See https://eips.ethereum.org/EIPS/eip-721\n */\ncontract IERC721Enumerable is IERC721 {\n    function totalSupply() public view returns (uint256);\n    function tokenOfOwnerByIndex(address owner, uint256 index) public view returns (uint256 tokenId);\n\n    function tokenByIndex(uint256 index) public view returns (uint256);\n}\n\n// File: @openzeppelin/contracts/token/ERC721/ERC721Enumerable.sol\n\npragma solidity ^0.5.0;\n\n\n\n\n/**\n * @title ERC-721 Non-Fungible Token with optional enumeration extension logic\n * @dev See https://eips.ethereum.org/EIPS/eip-721\n */\ncontract ERC721Enumerable is ERC165, ERC721, IERC721Enumerable {\n    // Mapping from owner to list of owned token IDs\n    mapping(address => uint256[]) private _ownedTokens;\n\n    // Mapping from token ID to index of the owner tokens list\n    mapping(uint256 => uint256) private _ownedTokensIndex;\n\n    // Array with all token ids, used for enumeration\n    uint256[] private _allTokens;\n\n    // Mapping from token id to position in the allTokens array\n    mapping(uint256 => uint256) private _allTokensIndex;\n\n    /*\n     *     bytes4(keccak256('totalSupply()')) == 0x18160ddd\n     *     bytes4(keccak256('tokenOfOwnerByIndex(address,uint256)')) == 0x2f745c59\n     *     bytes4(keccak256('tokenByIndex(uint256)')) == 0x4f6ccce7\n     *\n     *     => 0x18160ddd ^ 0x2f745c59 ^ 0x4f6ccce7 == 0x780e9d63\n     */\n    bytes4 private constant _INTERFACE_ID_ERC721_ENUMERABLE = 0x780e9d63;\n\n    /**\n     * @dev Constructor function.\n     */\n    constructor () public {\n        // register the supported interface to conform to ERC721Enumerable via ERC165\n        _registerInterface(_INTERFACE_ID_ERC721_ENUMERABLE);\n    }\n\n    /**\n     * @dev Gets the token ID at a given index of the tokens list of the requested owner.\n     * @param owner address owning the tokens list to be accessed\n     * @param index uint256 representing the index to be accessed of the requested tokens list\n     * @return uint256 token ID at the given index of the tokens list owned by the requested address\n     */\n    function tokenOfOwnerByIndex(address owner, uint256 index) public view returns (uint256) {\n        require(index < balanceOf(owner), \"ERC721Enumerable: owner index out of bounds\");\n        return _ownedTokens[owner][index];\n    }\n\n    /**\n     * @dev Gets the total amount of tokens stored by the contract.\n     * @return uint256 representing the total amount of tokens\n     */\n    function totalSupply() public view returns (uint256) {\n        return _allTokens.length;\n    }\n\n    /**\n     * @dev Gets the token ID at a given index of all the tokens in this contract\n     * Reverts if the index is greater or equal to the total number of tokens.\n     * @param index uint256 representing the index to be accessed of the tokens list\n     * @return uint256 token ID at the given index of the tokens list\n     */\n    function tokenByIndex(uint256 index) public view returns (uint256) {\n        require(index < totalSupply(), \"ERC721Enumerable: global index out of bounds\");\n        return _allTokens[index];\n    }\n\n    /**\n     * @dev Internal function to transfer ownership of a given token ID to another address.\n     * As opposed to transferFrom, this imposes no restrictions on msg.sender.\n     * @param from current owner of the token\n     * @param to address to receive the ownership of the given token ID\n     * @param tokenId uint256 ID of the token to be transferred\n     */\n    function _transferFrom(address from, address to, uint256 tokenId) internal {\n        super._transferFrom(from, to, tokenId);\n\n        _removeTokenFromOwnerEnumeration(from, tokenId);\n\n        _addTokenToOwnerEnumeration(to, tokenId);\n    }\n\n    /**\n     * @dev Internal function to mint a new token.\n     * Reverts if the given token ID already exists.\n     * @param to address the beneficiary that will own the minted token\n     * @param tokenId uint256 ID of the token to be minted\n     */\n    function _mint(address to, uint256 tokenId) internal {\n        super._mint(to, tokenId);\n\n        _addTokenToOwnerEnumeration(to, tokenId);\n\n        _addTokenToAllTokensEnumeration(tokenId);\n    }\n\n    /**\n     * @dev Internal function to burn a specific token.\n     * Reverts if the token does not exist.\n     * Deprecated, use _burn(uint256) instead.\n     * @param owner owner of the token to burn\n     * @param tokenId uint256 ID of the token being burned\n     */\n    function _burn(address owner, uint256 tokenId) internal {\n        super._burn(owner, tokenId);\n\n        _removeTokenFromOwnerEnumeration(owner, tokenId);\n        // Since tokenId will be deleted, we can clear its slot in _ownedTokensIndex to trigger a gas refund\n        _ownedTokensIndex[tokenId] = 0;\n\n        _removeTokenFromAllTokensEnumeration(tokenId);\n    }\n\n    /**\n     * @dev Gets the list of token IDs of the requested owner.\n     * @param owner address owning the tokens\n     * @return uint256[] List of token IDs owned by the requested address\n     */\n    function _tokensOfOwner(address owner) internal view returns (uint256[] storage) {\n        return _ownedTokens[owner];\n    }\n\n    /**\n     * @dev Private function to add a token to this extension's ownership-tracking data structures.\n     * @param to address representing the new owner of the given token ID\n     * @param tokenId uint256 ID of the token to be added to the tokens list of the given address\n     */\n    function _addTokenToOwnerEnumeration(address to, uint256 tokenId) private {\n        _ownedTokensIndex[tokenId] = _ownedTokens[to].length;\n        _ownedTokens[to].push(tokenId);\n    }\n\n    /**\n     * @dev Private function to add a token to this extension's token tracking data structures.\n     * @param tokenId uint256 ID of the token to be added to the tokens list\n     */\n    function _addTokenToAllTokensEnumeration(uint256 tokenId) private {\n        _allTokensIndex[tokenId] = _allTokens.length;\n        _allTokens.push(tokenId);\n    }\n\n    /**\n     * @dev Private function to remove a token from this extension's ownership-tracking data structures. Note that\n     * while the token is not assigned a new owner, the _ownedTokensIndex mapping is _not_ updated: this allows for\n     * gas optimizations e.g. when performing a transfer operation (avoiding double writes).\n     * This has O(1) time complexity, but alters the order of the _ownedTokens array.\n     * @param from address representing the previous owner of the given token ID\n     * @param tokenId uint256 ID of the token to be removed from the tokens list of the given address\n     */\n    function _removeTokenFromOwnerEnumeration(address from, uint256 tokenId) private {\n        // To prevent a gap in from's tokens array, we store the last token in the index of the token to delete, and\n        // then delete the last slot (swap and pop).\n\n        uint256 lastTokenIndex = _ownedTokens[from].length.sub(1);\n        uint256 tokenIndex = _ownedTokensIndex[tokenId];\n\n        // When the token to delete is the last token, the swap operation is unnecessary\n        if (tokenIndex != lastTokenIndex) {\n            uint256 lastTokenId = _ownedTokens[from][lastTokenIndex];\n\n            _ownedTokens[from][tokenIndex] = lastTokenId; // Move the last token to the slot of the to-delete token\n            _ownedTokensIndex[lastTokenId] = tokenIndex; // Update the moved token's index\n        }\n\n        // This also deletes the contents at the last position of the array\n        _ownedTokens[from].length--;\n\n        // Note that _ownedTokensIndex[tokenId] hasn't been cleared: it still points to the old slot (now occupied by\n        // lastTokenId, or just over the end of the array if the token was the last one).\n    }\n\n    /**\n     * @dev Private function to remove a token from this extension's token tracking data structures.\n     * This has O(1) time complexity, but alters the order of the _allTokens array.\n     * @param tokenId uint256 ID of the token to be removed from the tokens list\n     */\n    function _removeTokenFromAllTokensEnumeration(uint256 tokenId) private {\n        // To prevent a gap in the tokens array, we store the last token in the index of the token to delete, and\n        // then delete the last slot (swap and pop).\n\n        uint256 lastTokenIndex = _allTokens.length.sub(1);\n        uint256 tokenIndex = _allTokensIndex[tokenId];\n\n        // When the token to delete is the last token, the swap operation is unnecessary. However, since this occurs so\n        // rarely (when the last minted token is burnt) that we still do the swap here to avoid the gas cost of adding\n        // an 'if' statement (like in _removeTokenFromOwnerEnumeration)\n        uint256 lastTokenId = _allTokens[lastTokenIndex];\n\n        _allTokens[tokenIndex] = lastTokenId; // Move the last token to the slot of the to-delete token\n        _allTokensIndex[lastTokenId] = tokenIndex; // Update the moved token's index\n\n        // This also deletes the contents at the last position of the array\n        _allTokens.length--;\n        _allTokensIndex[tokenId] = 0;\n    }\n}\n\n// File: @openzeppelin/contracts/token/ERC721/IERC721Metadata.sol\n\npragma solidity ^0.5.0;\n\n\n/**\n * @title ERC-721 Non-Fungible Token Standard, optional metadata extension\n * @dev See https://eips.ethereum.org/EIPS/eip-721\n */\ncontract IERC721Metadata is IERC721 {\n    function name() external view returns (string memory);\n    function symbol() external view returns (string memory);\n    function tokenURI(uint256 tokenId) external view returns (string memory);\n}\n\n// File: @openzeppelin/contracts/token/ERC721/ERC721Metadata.sol\n\npragma solidity ^0.5.0;\n\n\n\n\ncontract ERC721Metadata is ERC165, ERC721, IERC721Metadata {\n    // Token name\n    string private _name;\n\n    // Token symbol\n    string private _symbol;\n\n    // Optional mapping for token URIs\n    mapping(uint256 => string) private _tokenURIs;\n\n    /*\n     *     bytes4(keccak256('name()')) == 0x06fdde03\n     *     bytes4(keccak256('symbol()')) == 0x95d89b41\n     *     bytes4(keccak256('tokenURI(uint256)')) == 0xc87b56dd\n     *\n     *     => 0x06fdde03 ^ 0x95d89b41 ^ 0xc87b56dd == 0x5b5e139f\n     */\n    bytes4 private constant _INTERFACE_ID_ERC721_METADATA = 0x5b5e139f;\n\n    /**\n     * @dev Constructor function\n     */\n    constructor (string memory name, string memory symbol) public {\n        _name = name;\n        _symbol = symbol;\n\n        // register the supported interfaces to conform to ERC721 via ERC165\n        _registerInterface(_INTERFACE_ID_ERC721_METADATA);\n    }\n\n    /**\n     * @dev Gets the token name.\n     * @return string representing the token name\n     */\n    function name() external view returns (string memory) {\n        return _name;\n    }\n\n    /**\n     * @dev Gets the token symbol.\n     * @return string representing the token symbol\n     */\n    function symbol() external view returns (string memory) {\n        return _symbol;\n    }\n\n    /**\n     * @dev Returns an URI for a given token ID.\n     * Throws if the token ID does not exist. May return an empty string.\n     * @param tokenId uint256 ID of the token to query\n     */\n    function tokenURI(uint256 tokenId) external view returns (string memory) {\n        require(_exists(tokenId), \"ERC721Metadata: URI query for nonexistent token\");\n        return _tokenURIs[tokenId];\n    }\n\n    /**\n     * @dev Internal function to set the token URI for a given token.\n     * Reverts if the token ID does not exist.\n     * @param tokenId uint256 ID of the token to set its URI\n     * @param uri string URI to assign\n     */\n    function _setTokenURI(uint256 tokenId, string memory uri) internal {\n        require(_exists(tokenId), \"ERC721Metadata: URI set of nonexistent token\");\n        _tokenURIs[tokenId] = uri;\n    }\n\n    /**\n     * @dev Internal function to burn a specific token.\n     * Reverts if the token does not exist.\n     * Deprecated, use _burn(uint256) instead.\n     * @param owner owner of the token to burn\n     * @param tokenId uint256 ID of the token being burned by the msg.sender\n     */\n    function _burn(address owner, uint256 tokenId) internal {\n        super._burn(owner, tokenId);\n\n        // Clear metadata (if any)\n        if (bytes(_tokenURIs[tokenId]).length != 0) {\n            delete _tokenURIs[tokenId];\n        }\n    }\n}\n\n// File: @openzeppelin/contracts/token/ERC721/ERC721Full.sol\n\npragma solidity ^0.5.0;\n\n\n\n\n/**\n * @title Full ERC721 Token\n * This implementation includes all the required and some optional functionality of the ERC721 standard\n * Moreover, it includes approve all functionality using operator terminology\n * @dev see https://eips.ethereum.org/EIPS/eip-721\n */\ncontract ERC721Full is ERC721, ERC721Enumerable, ERC721Metadata {\n    constructor (string memory name, string memory symbol) public ERC721Metadata(name, symbol) {\n        // solhint-disable-previous-line no-empty-blocks\n    }\n}\n",
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+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        }
+                      },
+                      {
+                        "argumentTypes": null,
+                        "id": 764,
+                        "name": "tokenId",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 727,
+                        "src": "21088:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      }
+                    ],
+                    "expression": {
+                      "argumentTypes": [
+                        {
+                          "typeIdentifier": "t_address_payable",
+                          "typeString": "address payable"
+                        },
+                        {
+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        },
+                        {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      ],
+                      "id": 759,
+                      "name": "Transfer",
+                      "nodeType": "Identifier",
+                      "overloadedDeclarations": [],
+                      "referencedDeclaration": 34,
+                      "src": "21063:8:1",
+                      "typeDescriptions": {
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+                    "isConstant": false,
+                    "isLValue": false,
+                    "isPure": false,
+                    "kind": "functionCall",
+                    "lValueRequested": false,
+                    "names": [],
+                    "nodeType": "FunctionCall",
+                    "src": "21063:33:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_tuple$__$",
+                      "typeString": "tuple()"
+                    }
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+                  "id": 766,
+                  "nodeType": "EmitStatement",
+                  "src": "21058:38:1"
+                }
+              ]
+            },
+            "documentation": "@dev Internal function to mint a new token.\nReverts if the given token ID already exists.\n@param to The address that will own the minted token\n@param tokenId uint256 ID of the token to be minted",
+            "id": 768,
+            "implemented": true,
+            "kind": "function",
+            "modifiers": [],
+            "name": "_mint",
+            "nodeType": "FunctionDefinition",
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+              "nodeType": "ParameterList",
+              "parameters": [
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+                  "id": 725,
+                  "name": "to",
+                  "nodeType": "VariableDeclaration",
+                  "scope": 768,
+                  "src": "20791:10:1",
+                  "stateVariable": false,
+                  "storageLocation": "default",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_address",
+                    "typeString": "address"
+                  },
+                  "typeName": {
+                    "id": 724,
+                    "name": "address",
+                    "nodeType": "ElementaryTypeName",
+                    "src": "20791:7:1",
+                    "stateMutability": "nonpayable",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_address",
+                      "typeString": "address"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                },
+                {
+                  "constant": false,
+                  "id": 727,
+                  "name": "tokenId",
+                  "nodeType": "VariableDeclaration",
+                  "scope": 768,
+                  "src": "20803:15:1",
+                  "stateVariable": false,
+                  "storageLocation": "default",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_uint256",
+                    "typeString": "uint256"
+                  },
+                  "typeName": {
+                    "id": 726,
+                    "name": "uint256",
+                    "nodeType": "ElementaryTypeName",
+                    "src": "20803:7:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_uint256",
+                      "typeString": "uint256"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                }
+              ],
+              "src": "20790:29:1"
+            },
+            "returnParameters": {
+              "id": 729,
+              "nodeType": "ParameterList",
+              "parameters": [],
+              "src": "20829:0:1"
+            },
+            "scope": 944,
+            "src": "20776:327:1",
+            "stateMutability": "nonpayable",
+            "superFunction": null,
+            "visibility": "internal"
+          },
+          {
+            "body": {
+              "id": 810,
+              "nodeType": "Block",
+              "src": "21434:268:1",
+              "statements": [
+                {
+                  "expression": {
+                    "argumentTypes": null,
+                    "arguments": [
+                      {
+                        "argumentTypes": null,
+                        "commonType": {
+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        },
+                        "id": 780,
+                        "isConstant": false,
+                        "isLValue": false,
+                        "isPure": false,
+                        "lValueRequested": false,
+                        "leftExpression": {
+                          "argumentTypes": null,
+                          "arguments": [
+                            {
+                              "argumentTypes": null,
+                              "id": 777,
+                              "name": "tokenId",
+                              "nodeType": "Identifier",
+                              "overloadedDeclarations": [],
+                              "referencedDeclaration": 772,
+                              "src": "21460:7:1",
+                              "typeDescriptions": {
+                                "typeIdentifier": "t_uint256",
+                                "typeString": "uint256"
+                              }
+                            }
+                          ],
+                          "expression": {
+                            "argumentTypes": [
+                              {
+                                "typeIdentifier": "t_uint256",
+                                "typeString": "uint256"
+                              }
+                            ],
+                            "id": 776,
+                            "name": "ownerOf",
+                            "nodeType": "Identifier",
+                            "overloadedDeclarations": [
+                              480
+                            ],
+                            "referencedDeclaration": 480,
+                            "src": "21452:7:1",
+                            "typeDescriptions": {
+                              "typeIdentifier": "t_function_internal_view$_t_uint256_$returns$_t_address_$",
+                              "typeString": "function (uint256) view returns (address)"
+                            }
+                          },
+                          "id": 778,
+                          "isConstant": false,
+                          "isLValue": false,
+                          "isPure": false,
+                          "kind": "functionCall",
+                          "lValueRequested": false,
+                          "names": [],
+                          "nodeType": "FunctionCall",
+                          "src": "21452:16:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_address",
+                            "typeString": "address"
+                          }
+                        },
+                        "nodeType": "BinaryOperation",
+                        "operator": "==",
+                        "rightExpression": {
+                          "argumentTypes": null,
+                          "id": 779,
+                          "name": "owner",
+                          "nodeType": "Identifier",
+                          "overloadedDeclarations": [],
+                          "referencedDeclaration": 770,
+                          "src": "21472:5:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_address",
+                            "typeString": "address"
+                          }
+                        },
+                        "src": "21452:25:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_bool",
+                          "typeString": "bool"
+                        }
+                      },
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+                        "argumentTypes": null,
+                        "hexValue": "4552433732313a206275726e206f6620746f6b656e2074686174206973206e6f74206f776e",
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+                        "isConstant": false,
+                        "isLValue": false,
+                        "isPure": true,
+                        "kind": "string",
+                        "lValueRequested": false,
+                        "nodeType": "Literal",
+                        "src": "21479:39:1",
+                        "subdenomination": null,
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_stringliteral_d9af5b321f427d3820b5fc07b432b1ddf1bb6411d5d926d9de9773fd616ab5ee",
+                          "typeString": "literal_string \"ERC721: burn of token that is not own\""
+                        },
+                        "value": "ERC721: burn of token that is not own"
+                      }
+                    ],
+                    "expression": {
+                      "argumentTypes": [
+                        {
+                          "typeIdentifier": "t_bool",
+                          "typeString": "bool"
+                        },
+                        {
+                          "typeIdentifier": "t_stringliteral_d9af5b321f427d3820b5fc07b432b1ddf1bb6411d5d926d9de9773fd616ab5ee",
+                          "typeString": "literal_string \"ERC721: burn of token that is not own\""
+                        }
+                      ],
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+                      "name": "require",
+                      "nodeType": "Identifier",
+                      "overloadedDeclarations": [
+                        1543,
+                        1544
+                      ],
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+                      "src": "21444:7:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_function_require_pure$_t_bool_$_t_string_memory_ptr_$returns$__$",
+                        "typeString": "function (bool,string memory) pure"
+                      }
+                    },
+                    "id": 782,
+                    "isConstant": false,
+                    "isLValue": false,
+                    "isPure": false,
+                    "kind": "functionCall",
+                    "lValueRequested": false,
+                    "names": [],
+                    "nodeType": "FunctionCall",
+                    "src": "21444:75:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_tuple$__$",
+                      "typeString": "tuple()"
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+                  },
+                  "id": 783,
+                  "nodeType": "ExpressionStatement",
+                  "src": "21444:75:1"
+                },
+                {
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+                    "argumentTypes": null,
+                    "arguments": [
+                      {
+                        "argumentTypes": null,
+                        "id": 785,
+                        "name": "tokenId",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 772,
+                        "src": "21545:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      }
+                    ],
+                    "expression": {
+                      "argumentTypes": [
+                        {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      ],
+                      "id": 784,
+                      "name": "_clearApproval",
+                      "nodeType": "Identifier",
+                      "overloadedDeclarations": [],
+                      "referencedDeclaration": 943,
+                      "src": "21530:14:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_function_internal_nonpayable$_t_uint256_$returns$__$",
+                        "typeString": "function (uint256)"
+                      }
+                    },
+                    "id": 786,
+                    "isConstant": false,
+                    "isLValue": false,
+                    "isPure": false,
+                    "kind": "functionCall",
+                    "lValueRequested": false,
+                    "names": [],
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+                    "src": "21530:23:1",
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+                      "typeString": "tuple()"
+                    }
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+                  "nodeType": "ExpressionStatement",
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+                },
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+                      "expression": {
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+                        "baseExpression": {
+                          "argumentTypes": null,
+                          "id": 788,
+                          "name": "_ownedTokensCount",
+                          "nodeType": "Identifier",
+                          "overloadedDeclarations": [],
+                          "referencedDeclaration": 415,
+                          "src": "21564:17:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_mapping$_t_address_$_t_struct$_Counter_$296_storage_$",
+                            "typeString": "mapping(address => struct Counters.Counter storage ref)"
+                          }
+                        },
+                        "id": 790,
+                        "indexExpression": {
+                          "argumentTypes": null,
+                          "id": 789,
+                          "name": "owner",
+                          "nodeType": "Identifier",
+                          "overloadedDeclarations": [],
+                          "referencedDeclaration": 770,
+                          "src": "21582:5:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_address",
+                            "typeString": "address"
+                          }
+                        },
+                        "isConstant": false,
+                        "isLValue": true,
+                        "isPure": false,
+                        "lValueRequested": false,
+                        "nodeType": "IndexAccess",
+                        "src": "21564:24:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_struct$_Counter_$296_storage",
+                          "typeString": "struct Counters.Counter storage ref"
+                        }
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+                      "id": 791,
+                      "isConstant": false,
+                      "isLValue": true,
+                      "isPure": false,
+                      "lValueRequested": false,
+                      "memberName": "decrement",
+                      "nodeType": "MemberAccess",
+                      "referencedDeclaration": 335,
+                      "src": "21564:34:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_function_internal_nonpayable$_t_struct$_Counter_$296_storage_ptr_$returns$__$bound_to$_t_struct$_Counter_$296_storage_ptr_$",
+                        "typeString": "function (struct Counters.Counter storage pointer)"
+                      }
+                    },
+                    "id": 792,
+                    "isConstant": false,
+                    "isLValue": false,
+                    "isPure": false,
+                    "kind": "functionCall",
+                    "lValueRequested": false,
+                    "names": [],
+                    "nodeType": "FunctionCall",
+                    "src": "21564:36:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_tuple$__$",
+                      "typeString": "tuple()"
+                    }
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+                  "id": 793,
+                  "nodeType": "ExpressionStatement",
+                  "src": "21564:36:1"
+                },
+                {
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+                    "id": 800,
+                    "isConstant": false,
+                    "isLValue": false,
+                    "isPure": false,
+                    "lValueRequested": false,
+                    "leftHandSide": {
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+                      "baseExpression": {
+                        "argumentTypes": null,
+                        "id": 794,
+                        "name": "_tokenOwner",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 407,
+                        "src": "21610:11:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_mapping$_t_uint256_$_t_address_$",
+                          "typeString": "mapping(uint256 => address)"
+                        }
+                      },
+                      "id": 796,
+                      "indexExpression": {
+                        "argumentTypes": null,
+                        "id": 795,
+                        "name": "tokenId",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 772,
+                        "src": "21622:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      },
+                      "isConstant": false,
+                      "isLValue": true,
+                      "isPure": false,
+                      "lValueRequested": true,
+                      "nodeType": "IndexAccess",
+                      "src": "21610:20:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_address",
+                        "typeString": "address"
+                      }
+                    },
+                    "nodeType": "Assignment",
+                    "operator": "=",
+                    "rightHandSide": {
+                      "argumentTypes": null,
+                      "arguments": [
+                        {
+                          "argumentTypes": null,
+                          "hexValue": "30",
+                          "id": 798,
+                          "isConstant": false,
+                          "isLValue": false,
+                          "isPure": true,
+                          "kind": "number",
+                          "lValueRequested": false,
+                          "nodeType": "Literal",
+                          "src": "21641:1:1",
+                          "subdenomination": null,
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_rational_0_by_1",
+                            "typeString": "int_const 0"
+                          },
+                          "value": "0"
+                        }
+                      ],
+                      "expression": {
+                        "argumentTypes": [
+                          {
+                            "typeIdentifier": "t_rational_0_by_1",
+                            "typeString": "int_const 0"
+                          }
+                        ],
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+                        "isConstant": false,
+                        "isLValue": false,
+                        "isPure": true,
+                        "lValueRequested": false,
+                        "nodeType": "ElementaryTypeNameExpression",
+                        "src": "21633:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_type$_t_address_$",
+                          "typeString": "type(address)"
+                        },
+                        "typeName": "address"
+                      },
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+                      "isConstant": false,
+                      "isLValue": false,
+                      "isPure": true,
+                      "kind": "typeConversion",
+                      "lValueRequested": false,
+                      "names": [],
+                      "nodeType": "FunctionCall",
+                      "src": "21633:10:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_address_payable",
+                        "typeString": "address payable"
+                      }
+                    },
+                    "src": "21610:33:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_address",
+                      "typeString": "address"
+                    }
+                  },
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+                  "nodeType": "ExpressionStatement",
+                  "src": "21610:33:1"
+                },
+                {
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+                    "arguments": [
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+                        "argumentTypes": null,
+                        "id": 803,
+                        "name": "owner",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 770,
+                        "src": "21668:5:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        }
+                      },
+                      {
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+                        "arguments": [
+                          {
+                            "argumentTypes": null,
+                            "hexValue": "30",
+                            "id": 805,
+                            "isConstant": false,
+                            "isLValue": false,
+                            "isPure": true,
+                            "kind": "number",
+                            "lValueRequested": false,
+                            "nodeType": "Literal",
+                            "src": "21683:1:1",
+                            "subdenomination": null,
+                            "typeDescriptions": {
+                              "typeIdentifier": "t_rational_0_by_1",
+                              "typeString": "int_const 0"
+                            },
+                            "value": "0"
+                          }
+                        ],
+                        "expression": {
+                          "argumentTypes": [
+                            {
+                              "typeIdentifier": "t_rational_0_by_1",
+                              "typeString": "int_const 0"
+                            }
+                          ],
+                          "id": 804,
+                          "isConstant": false,
+                          "isLValue": false,
+                          "isPure": true,
+                          "lValueRequested": false,
+                          "nodeType": "ElementaryTypeNameExpression",
+                          "src": "21675:7:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_type$_t_address_$",
+                            "typeString": "type(address)"
+                          },
+                          "typeName": "address"
+                        },
+                        "id": 806,
+                        "isConstant": false,
+                        "isLValue": false,
+                        "isPure": true,
+                        "kind": "typeConversion",
+                        "lValueRequested": false,
+                        "names": [],
+                        "nodeType": "FunctionCall",
+                        "src": "21675:10:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_address_payable",
+                          "typeString": "address payable"
+                        }
+                      },
+                      {
+                        "argumentTypes": null,
+                        "id": 807,
+                        "name": "tokenId",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 772,
+                        "src": "21687:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      }
+                    ],
+                    "expression": {
+                      "argumentTypes": [
+                        {
+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        },
+                        {
+                          "typeIdentifier": "t_address_payable",
+                          "typeString": "address payable"
+                        },
+                        {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      ],
+                      "id": 802,
+                      "name": "Transfer",
+                      "nodeType": "Identifier",
+                      "overloadedDeclarations": [],
+                      "referencedDeclaration": 34,
+                      "src": "21659:8:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_function_event_nonpayable$_t_address_$_t_address_$_t_uint256_$returns$__$",
+                        "typeString": "function (address,address,uint256)"
+                      }
+                    },
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+                    "isConstant": false,
+                    "isLValue": false,
+                    "isPure": false,
+                    "kind": "functionCall",
+                    "lValueRequested": false,
+                    "names": [],
+                    "nodeType": "FunctionCall",
+                    "src": "21659:36:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_tuple$__$",
+                      "typeString": "tuple()"
+                    }
+                  },
+                  "id": 809,
+                  "nodeType": "EmitStatement",
+                  "src": "21654:41:1"
+                }
+              ]
+            },
+            "documentation": "@dev Internal function to burn a specific token.\nReverts if the token does not exist.\nDeprecated, use _burn(uint256) instead.\n@param owner owner of the token to burn\n@param tokenId uint256 ID of the token being burned",
+            "id": 811,
+            "implemented": true,
+            "kind": "function",
+            "modifiers": [],
+            "name": "_burn",
+            "nodeType": "FunctionDefinition",
+            "parameters": {
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+              "nodeType": "ParameterList",
+              "parameters": [
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+                  "id": 770,
+                  "name": "owner",
+                  "nodeType": "VariableDeclaration",
+                  "scope": 811,
+                  "src": "21393:13:1",
+                  "stateVariable": false,
+                  "storageLocation": "default",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_address",
+                    "typeString": "address"
+                  },
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+                    "id": 769,
+                    "name": "address",
+                    "nodeType": "ElementaryTypeName",
+                    "src": "21393:7:1",
+                    "stateMutability": "nonpayable",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_address",
+                      "typeString": "address"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                },
+                {
+                  "constant": false,
+                  "id": 772,
+                  "name": "tokenId",
+                  "nodeType": "VariableDeclaration",
+                  "scope": 811,
+                  "src": "21408:15:1",
+                  "stateVariable": false,
+                  "storageLocation": "default",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_uint256",
+                    "typeString": "uint256"
+                  },
+                  "typeName": {
+                    "id": 771,
+                    "name": "uint256",
+                    "nodeType": "ElementaryTypeName",
+                    "src": "21408:7:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_uint256",
+                      "typeString": "uint256"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                }
+              ],
+              "src": "21392:32:1"
+            },
+            "returnParameters": {
+              "id": 774,
+              "nodeType": "ParameterList",
+              "parameters": [],
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+                          "typeString": "address"
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+                          "typeString": "uint256"
+                        }
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+                        {
+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        },
+                        {
+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        },
+                        {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
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+                          "name": "msg",
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+                          "src": "23630:3:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_magic_message",
+                            "typeString": "msg"
+                          }
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+                        "isPure": false,
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+                        "src": "23630:10:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_address_payable",
+                          "typeString": "address payable"
+                        }
+                      },
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+                        "name": "from",
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+                        "typeDescriptions": {
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+                          "typeString": "address"
+                        }
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+                        "name": "tokenId",
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+                        "src": "23648:7:1",
+                        "typeDescriptions": {
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+                        }
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+                          "typeIdentifier": "t_bytes_memory_ptr",
+                          "typeString": "bytes memory"
+                        }
+                      }
+                    ],
+                    "expression": {
+                      "argumentTypes": [
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+                          "typeIdentifier": "t_address_payable",
+                          "typeString": "address payable"
+                        },
+                        {
+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        },
+                        {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        },
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+                              "typeString": "address"
+                            }
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+                        ],
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+                              "typeIdentifier": "t_address",
+                              "typeString": "address"
+                            }
+                          ],
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+                          "name": "IERC721Receiver",
+                          "nodeType": "Identifier",
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+                          "referencedDeclaration": 139,
+                          "src": "23593:15:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_type$_t_contract$_IERC721Receiver_$139_$",
+                            "typeString": "type(contract IERC721Receiver)"
+                          }
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+                        "kind": "typeConversion",
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+                          "typeIdentifier": "t_contract$_IERC721Receiver_$139",
+                          "typeString": "contract IERC721Receiver"
+                        }
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+                      }
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+                    }
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+                        "commonType": {
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+                          "typeString": "bytes4"
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+                          "src": "23681:6:1",
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+                            "typeIdentifier": "t_bytes4",
+                            "typeString": "bytes4"
+                          }
+                        },
+                        "nodeType": "BinaryOperation",
+                        "operator": "==",
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+                          "id": 915,
+                          "name": "_ERC721_RECEIVED",
+                          "nodeType": "Identifier",
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+                          "referencedDeclaration": 403,
+                          "src": "23691:16:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_bytes4",
+                            "typeString": "bytes4"
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+                          "typeString": "bool"
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+                  "nodeType": "Return",
+                  "src": "23673:35:1"
+                }
+              ]
+            },
+            "documentation": "@dev Internal function to invoke `onERC721Received` on a target address.\nThe call is not executed if the target address is not a contract.\n     * This function is deprecated.\n@param from address representing the previous owner of the given token ID\n@param to target address that will receive the tokens\n@param tokenId uint256 ID of the token to be transferred\n@param _data bytes optional data to send along with the call\n@return bool whether the call correctly returned the expected magic value",
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+                    "src": "23426:7:1",
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+                  "src": "23443:18:1",
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+                  "storageLocation": "memory",
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+                          "typeString": "bool"
+                        },
+                        {
+                          "typeIdentifier": "t_stringliteral_d269a4e9f5820dcdb69ea21f528512eb9b927c8d846d48aa51c9219f461d4dcc",
+                          "typeString": "literal_string \"ERC721Enumerable: global index out of bounds\""
+                        }
+                      ],
+                      "id": 1044,
+                      "name": "require",
+                      "nodeType": "Identifier",
+                      "overloadedDeclarations": [
+                        1543,
+                        1544
+                      ],
+                      "referencedDeclaration": 1544,
+                      "src": "27171:7:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_function_require_pure$_t_bool_$_t_string_memory_ptr_$returns$__$",
+                        "typeString": "function (bool,string memory) pure"
+                      }
+                    },
+                    "id": 1050,
+                    "isConstant": false,
+                    "isLValue": false,
+                    "isPure": false,
+                    "kind": "functionCall",
+                    "lValueRequested": false,
+                    "names": [],
+                    "nodeType": "FunctionCall",
+                    "src": "27171:78:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_tuple$__$",
+                      "typeString": "tuple()"
+                    }
+                  },
+                  "id": 1051,
+                  "nodeType": "ExpressionStatement",
+                  "src": "27171:78:1"
+                },
+                {
+                  "expression": {
+                    "argumentTypes": null,
+                    "baseExpression": {
+                      "argumentTypes": null,
+                      "id": 1052,
+                      "name": "_allTokens",
+                      "nodeType": "Identifier",
+                      "overloadedDeclarations": [],
+                      "referencedDeclaration": 988,
+                      "src": "27266:10:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_array$_t_uint256_$dyn_storage",
+                        "typeString": "uint256[] storage ref"
+                      }
+                    },
+                    "id": 1054,
+                    "indexExpression": {
+                      "argumentTypes": null,
+                      "id": 1053,
+                      "name": "index",
+                      "nodeType": "Identifier",
+                      "overloadedDeclarations": [],
+                      "referencedDeclaration": 1039,
+                      "src": "27277:5:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_uint256",
+                        "typeString": "uint256"
+                      }
+                    },
+                    "isConstant": false,
+                    "isLValue": true,
+                    "isPure": false,
+                    "lValueRequested": false,
+                    "nodeType": "IndexAccess",
+                    "src": "27266:17:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_uint256",
+                      "typeString": "uint256"
+                    }
+                  },
+                  "functionReturnParameters": 1043,
+                  "id": 1055,
+                  "nodeType": "Return",
+                  "src": "27259:24:1"
+                }
+              ]
+            },
+            "documentation": "@dev Gets the token ID at a given index of all the tokens in this contract\nReverts if the index is greater or equal to the total number of tokens.\n@param index uint256 representing the index to be accessed of the tokens list\n@return uint256 token ID at the given index of the tokens list",
+            "id": 1057,
+            "implemented": true,
+            "kind": "function",
+            "modifiers": [],
+            "name": "tokenByIndex",
+            "nodeType": "FunctionDefinition",
+            "parameters": {
+              "id": 1040,
+              "nodeType": "ParameterList",
+              "parameters": [
+                {
+                  "constant": false,
+                  "id": 1039,
+                  "name": "index",
+                  "nodeType": "VariableDeclaration",
+                  "scope": 1057,
+                  "src": "27116:13:1",
+                  "stateVariable": false,
+                  "storageLocation": "default",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_uint256",
+                    "typeString": "uint256"
+                  },
+                  "typeName": {
+                    "id": 1038,
+                    "name": "uint256",
+                    "nodeType": "ElementaryTypeName",
+                    "src": "27116:7:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_uint256",
+                      "typeString": "uint256"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                }
+              ],
+              "src": "27115:15:1"
+            },
+            "returnParameters": {
+              "id": 1043,
+              "nodeType": "ParameterList",
+              "parameters": [
+                {
+                  "constant": false,
+                  "id": 1042,
+                  "name": "",
+                  "nodeType": "VariableDeclaration",
+                  "scope": 1057,
+                  "src": "27152:7:1",
+                  "stateVariable": false,
+                  "storageLocation": "default",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_uint256",
+                    "typeString": "uint256"
+                  },
+                  "typeName": {
+                    "id": 1041,
+                    "name": "uint256",
+                    "nodeType": "ElementaryTypeName",
+                    "src": "27152:7:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_uint256",
+                      "typeString": "uint256"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                }
+              ],
+              "src": "27151:9:1"
+            },
+            "scope": 1302,
+            "src": "27094:196:1",
+            "stateMutability": "view",
+            "superFunction": 968,
+            "visibility": "public"
+          },
+          {
+            "body": {
+              "id": 1084,
+              "nodeType": "Block",
+              "src": "27740:164:1",
+              "statements": [
+                {
+                  "expression": {
+                    "argumentTypes": null,
+                    "arguments": [
+                      {
+                        "argumentTypes": null,
+                        "id": 1069,
+                        "name": "from",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 1059,
+                        "src": "27770:4:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        }
+                      },
+                      {
+                        "argumentTypes": null,
+                        "id": 1070,
+                        "name": "to",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 1061,
+                        "src": "27776:2:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        }
+                      },
+                      {
+                        "argumentTypes": null,
+                        "id": 1071,
+                        "name": "tokenId",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 1063,
+                        "src": "27780:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      }
+                    ],
+                    "expression": {
+                      "argumentTypes": [
+                        {
+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        },
+                        {
+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        },
+                        {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      ],
+                      "expression": {
+                        "argumentTypes": null,
+                        "id": 1066,
+                        "name": "super",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 1572,
+                        "src": "27750:5:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_super$_ERC721Enumerable_$1302",
+                          "typeString": "contract super ERC721Enumerable"
+                        }
+                      },
+                      "id": 1068,
+                      "isConstant": false,
+                      "isLValue": false,
+                      "isPure": false,
+                      "lValueRequested": false,
+                      "memberName": "_transferFrom",
+                      "nodeType": "MemberAccess",
+                      "referencedDeclaration": 880,
+                      "src": "27750:19:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_function_internal_nonpayable$_t_address_$_t_address_$_t_uint256_$returns$__$",
+                        "typeString": "function (address,address,uint256)"
+                      }
+                    },
+                    "id": 1072,
+                    "isConstant": false,
+                    "isLValue": false,
+                    "isPure": false,
+                    "kind": "functionCall",
+                    "lValueRequested": false,
+                    "names": [],
+                    "nodeType": "FunctionCall",
+                    "src": "27750:38:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_tuple$__$",
+                      "typeString": "tuple()"
+                    }
+                  },
+                  "id": 1073,
+                  "nodeType": "ExpressionStatement",
+                  "src": "27750:38:1"
+                },
+                {
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+                    "argumentTypes": null,
+                    "arguments": [
+                      {
+                        "argumentTypes": null,
+                        "id": 1075,
+                        "name": "from",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 1059,
+                        "src": "27832:4:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        }
+                      },
+                      {
+                        "argumentTypes": null,
+                        "id": 1076,
+                        "name": "tokenId",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 1063,
+                        "src": "27838:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      }
+                    ],
+                    "expression": {
+                      "argumentTypes": [
+                        {
+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        },
+                        {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      ],
+                      "id": 1074,
+                      "name": "_removeTokenFromOwnerEnumeration",
+                      "nodeType": "Identifier",
+                      "overloadedDeclarations": [],
+                      "referencedDeclaration": 1252,
+                      "src": "27799:32:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_function_internal_nonpayable$_t_address_$_t_uint256_$returns$__$",
+                        "typeString": "function (address,uint256)"
+                      }
+                    },
+                    "id": 1077,
+                    "isConstant": false,
+                    "isLValue": false,
+                    "isPure": false,
+                    "kind": "functionCall",
+                    "lValueRequested": false,
+                    "names": [],
+                    "nodeType": "FunctionCall",
+                    "src": "27799:47:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_tuple$__$",
+                      "typeString": "tuple()"
+                    }
+                  },
+                  "id": 1078,
+                  "nodeType": "ExpressionStatement",
+                  "src": "27799:47:1"
+                },
+                {
+                  "expression": {
+                    "argumentTypes": null,
+                    "arguments": [
+                      {
+                        "argumentTypes": null,
+                        "id": 1080,
+                        "name": "to",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 1061,
+                        "src": "27885:2:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        }
+                      },
+                      {
+                        "argumentTypes": null,
+                        "id": 1081,
+                        "name": "tokenId",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 1063,
+                        "src": "27889:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      }
+                    ],
+                    "expression": {
+                      "argumentTypes": [
+                        {
+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        },
+                        {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      ],
+                      "id": 1079,
+                      "name": "_addTokenToOwnerEnumeration",
+                      "nodeType": "Identifier",
+                      "overloadedDeclarations": [],
+                      "referencedDeclaration": 1176,
+                      "src": "27857:27:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_function_internal_nonpayable$_t_address_$_t_uint256_$returns$__$",
+                        "typeString": "function (address,uint256)"
+                      }
+                    },
+                    "id": 1082,
+                    "isConstant": false,
+                    "isLValue": false,
+                    "isPure": false,
+                    "kind": "functionCall",
+                    "lValueRequested": false,
+                    "names": [],
+                    "nodeType": "FunctionCall",
+                    "src": "27857:40:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_tuple$__$",
+                      "typeString": "tuple()"
+                    }
+                  },
+                  "id": 1083,
+                  "nodeType": "ExpressionStatement",
+                  "src": "27857:40:1"
+                }
+              ]
+            },
+            "documentation": "@dev Internal function to transfer ownership of a given token ID to another address.\nAs opposed to transferFrom, this imposes no restrictions on msg.sender.\n@param from current owner of the token\n@param to address to receive the ownership of the given token ID\n@param tokenId uint256 ID of the token to be transferred",
+            "id": 1085,
+            "implemented": true,
+            "kind": "function",
+            "modifiers": [],
+            "name": "_transferFrom",
+            "nodeType": "FunctionDefinition",
+            "parameters": {
+              "id": 1064,
+              "nodeType": "ParameterList",
+              "parameters": [
+                {
+                  "constant": false,
+                  "id": 1059,
+                  "name": "from",
+                  "nodeType": "VariableDeclaration",
+                  "scope": 1085,
+                  "src": "27688:12:1",
+                  "stateVariable": false,
+                  "storageLocation": "default",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_address",
+                    "typeString": "address"
+                  },
+                  "typeName": {
+                    "id": 1058,
+                    "name": "address",
+                    "nodeType": "ElementaryTypeName",
+                    "src": "27688:7:1",
+                    "stateMutability": "nonpayable",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_address",
+                      "typeString": "address"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                },
+                {
+                  "constant": false,
+                  "id": 1061,
+                  "name": "to",
+                  "nodeType": "VariableDeclaration",
+                  "scope": 1085,
+                  "src": "27702:10:1",
+                  "stateVariable": false,
+                  "storageLocation": "default",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_address",
+                    "typeString": "address"
+                  },
+                  "typeName": {
+                    "id": 1060,
+                    "name": "address",
+                    "nodeType": "ElementaryTypeName",
+                    "src": "27702:7:1",
+                    "stateMutability": "nonpayable",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_address",
+                      "typeString": "address"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                },
+                {
+                  "constant": false,
+                  "id": 1063,
+                  "name": "tokenId",
+                  "nodeType": "VariableDeclaration",
+                  "scope": 1085,
+                  "src": "27714:15:1",
+                  "stateVariable": false,
+                  "storageLocation": "default",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_uint256",
+                    "typeString": "uint256"
+                  },
+                  "typeName": {
+                    "id": 1062,
+                    "name": "uint256",
+                    "nodeType": "ElementaryTypeName",
+                    "src": "27714:7:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_uint256",
+                      "typeString": "uint256"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                }
+              ],
+              "src": "27687:43:1"
+            },
+            "returnParameters": {
+              "id": 1065,
+              "nodeType": "ParameterList",
+              "parameters": [],
+              "src": "27740:0:1"
+            },
+            "scope": 1302,
+            "src": "27665:239:1",
+            "stateMutability": "nonpayable",
+            "superFunction": 880,
+            "visibility": "internal"
+          },
+          {
+            "body": {
+              "id": 1108,
+              "nodeType": "Block",
+              "src": "28214:143:1",
+              "statements": [
+                {
+                  "expression": {
+                    "argumentTypes": null,
+                    "arguments": [
+                      {
+                        "argumentTypes": null,
+                        "id": 1095,
+                        "name": "to",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 1087,
+                        "src": "28236:2:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        }
+                      },
+                      {
+                        "argumentTypes": null,
+                        "id": 1096,
+                        "name": "tokenId",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 1089,
+                        "src": "28240:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      }
+                    ],
+                    "expression": {
+                      "argumentTypes": [
+                        {
+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        },
+                        {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      ],
+                      "expression": {
+                        "argumentTypes": null,
+                        "id": 1092,
+                        "name": "super",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 1572,
+                        "src": "28224:5:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_super$_ERC721Enumerable_$1302",
+                          "typeString": "contract super ERC721Enumerable"
+                        }
+                      },
+                      "id": 1094,
+                      "isConstant": false,
+                      "isLValue": false,
+                      "isPure": false,
+                      "lValueRequested": false,
+                      "memberName": "_mint",
+                      "nodeType": "MemberAccess",
+                      "referencedDeclaration": 768,
+                      "src": "28224:11:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_function_internal_nonpayable$_t_address_$_t_uint256_$returns$__$",
+                        "typeString": "function (address,uint256)"
+                      }
+                    },
+                    "id": 1097,
+                    "isConstant": false,
+                    "isLValue": false,
+                    "isPure": false,
+                    "kind": "functionCall",
+                    "lValueRequested": false,
+                    "names": [],
+                    "nodeType": "FunctionCall",
+                    "src": "28224:24:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_tuple$__$",
+                      "typeString": "tuple()"
+                    }
+                  },
+                  "id": 1098,
+                  "nodeType": "ExpressionStatement",
+                  "src": "28224:24:1"
+                },
+                {
+                  "expression": {
+                    "argumentTypes": null,
+                    "arguments": [
+                      {
+                        "argumentTypes": null,
+                        "id": 1100,
+                        "name": "to",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 1087,
+                        "src": "28287:2:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        }
+                      },
+                      {
+                        "argumentTypes": null,
+                        "id": 1101,
+                        "name": "tokenId",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 1089,
+                        "src": "28291:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      }
+                    ],
+                    "expression": {
+                      "argumentTypes": [
+                        {
+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        },
+                        {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      ],
+                      "id": 1099,
+                      "name": "_addTokenToOwnerEnumeration",
+                      "nodeType": "Identifier",
+                      "overloadedDeclarations": [],
+                      "referencedDeclaration": 1176,
+                      "src": "28259:27:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_function_internal_nonpayable$_t_address_$_t_uint256_$returns$__$",
+                        "typeString": "function (address,uint256)"
+                      }
+                    },
+                    "id": 1102,
+                    "isConstant": false,
+                    "isLValue": false,
+                    "isPure": false,
+                    "kind": "functionCall",
+                    "lValueRequested": false,
+                    "names": [],
+                    "nodeType": "FunctionCall",
+                    "src": "28259:40:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_tuple$__$",
+                      "typeString": "tuple()"
+                    }
+                  },
+                  "id": 1103,
+                  "nodeType": "ExpressionStatement",
+                  "src": "28259:40:1"
+                },
+                {
+                  "expression": {
+                    "argumentTypes": null,
+                    "arguments": [
+                      {
+                        "argumentTypes": null,
+                        "id": 1105,
+                        "name": "tokenId",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 1089,
+                        "src": "28342:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      }
+                    ],
+                    "expression": {
+                      "argumentTypes": [
+                        {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      ],
+                      "id": 1104,
+                      "name": "_addTokenToAllTokensEnumeration",
+                      "nodeType": "Identifier",
+                      "overloadedDeclarations": [],
+                      "referencedDeclaration": 1195,
+                      "src": "28310:31:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_function_internal_nonpayable$_t_uint256_$returns$__$",
+                        "typeString": "function (uint256)"
+                      }
+                    },
+                    "id": 1106,
+                    "isConstant": false,
+                    "isLValue": false,
+                    "isPure": false,
+                    "kind": "functionCall",
+                    "lValueRequested": false,
+                    "names": [],
+                    "nodeType": "FunctionCall",
+                    "src": "28310:40:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_tuple$__$",
+                      "typeString": "tuple()"
+                    }
+                  },
+                  "id": 1107,
+                  "nodeType": "ExpressionStatement",
+                  "src": "28310:40:1"
+                }
+              ]
+            },
+            "documentation": "@dev Internal function to mint a new token.\nReverts if the given token ID already exists.\n@param to address the beneficiary that will own the minted token\n@param tokenId uint256 ID of the token to be minted",
+            "id": 1109,
+            "implemented": true,
+            "kind": "function",
+            "modifiers": [],
+            "name": "_mint",
+            "nodeType": "FunctionDefinition",
+            "parameters": {
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+              "nodeType": "ParameterList",
+              "parameters": [
+                {
+                  "constant": false,
+                  "id": 1087,
+                  "name": "to",
+                  "nodeType": "VariableDeclaration",
+                  "scope": 1109,
+                  "src": "28176:10:1",
+                  "stateVariable": false,
+                  "storageLocation": "default",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_address",
+                    "typeString": "address"
+                  },
+                  "typeName": {
+                    "id": 1086,
+                    "name": "address",
+                    "nodeType": "ElementaryTypeName",
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+                    "stateMutability": "nonpayable",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_address",
+                      "typeString": "address"
+                    }
+                  },
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+                  "visibility": "internal"
+                },
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+                  "stateVariable": false,
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+                    "typeString": "uint256"
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+                      "typeString": "uint256"
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+                  "visibility": "internal"
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+            "src": "28161:196:1",
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+            "visibility": "internal"
+          },
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+                        "src": "28710:5:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        }
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+                        "name": "tokenId",
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+                        "src": "28717:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
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+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        },
+                        {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
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+                        "src": "28698:5:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_super$_ERC721Enumerable_$1302",
+                          "typeString": "contract super ERC721Enumerable"
+                        }
+                      },
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+                      "isConstant": false,
+                      "isLValue": false,
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+                      "lValueRequested": false,
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+                      "src": "28698:11:1",
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+                        "typeString": "function (address,uint256)"
+                      }
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+                        "src": "28769:5:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        }
+                      },
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+                        "id": 1125,
+                        "name": "tokenId",
+                        "nodeType": "Identifier",
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+                        "src": "28776:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      }
+                    ],
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+                        {
+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        },
+                        {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      ],
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+                      "name": "_removeTokenFromOwnerEnumeration",
+                      "nodeType": "Identifier",
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+                      "src": "28736:32:1",
+                      "typeDescriptions": {
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+                        "typeString": "function (address,uint256)"
+                      }
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+                    "isPure": false,
+                    "kind": "functionCall",
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+                    "nodeType": "FunctionCall",
+                    "src": "28736:48:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_tuple$__$",
+                      "typeString": "tuple()"
+                    }
+                  },
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+                  "src": "28736:48:1"
+                },
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+                    "lValueRequested": false,
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+                      "baseExpression": {
+                        "argumentTypes": null,
+                        "id": 1128,
+                        "name": "_ownedTokensIndex",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 985,
+                        "src": "28903:17:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_mapping$_t_uint256_$_t_uint256_$",
+                          "typeString": "mapping(uint256 => uint256)"
+                        }
+                      },
+                      "id": 1130,
+                      "indexExpression": {
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+                        "id": 1129,
+                        "name": "tokenId",
+                        "nodeType": "Identifier",
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+                        "referencedDeclaration": 1113,
+                        "src": "28921:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
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+                      "isLValue": true,
+                      "isPure": false,
+                      "lValueRequested": true,
+                      "nodeType": "IndexAccess",
+                      "src": "28903:26:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_uint256",
+                        "typeString": "uint256"
+                      }
+                    },
+                    "nodeType": "Assignment",
+                    "operator": "=",
+                    "rightHandSide": {
+                      "argumentTypes": null,
+                      "hexValue": "30",
+                      "id": 1131,
+                      "isConstant": false,
+                      "isLValue": false,
+                      "isPure": true,
+                      "kind": "number",
+                      "lValueRequested": false,
+                      "nodeType": "Literal",
+                      "src": "28932:1:1",
+                      "subdenomination": null,
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_rational_0_by_1",
+                        "typeString": "int_const 0"
+                      },
+                      "value": "0"
+                    },
+                    "src": "28903:30:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_uint256",
+                      "typeString": "uint256"
+                    }
+                  },
+                  "id": 1133,
+                  "nodeType": "ExpressionStatement",
+                  "src": "28903:30:1"
+                },
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+                    "arguments": [
+                      {
+                        "argumentTypes": null,
+                        "id": 1135,
+                        "name": "tokenId",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 1113,
+                        "src": "28981:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      }
+                    ],
+                    "expression": {
+                      "argumentTypes": [
+                        {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      ],
+                      "id": 1134,
+                      "name": "_removeTokenFromAllTokensEnumeration",
+                      "nodeType": "Identifier",
+                      "overloadedDeclarations": [],
+                      "referencedDeclaration": 1301,
+                      "src": "28944:36:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_function_internal_nonpayable$_t_uint256_$returns$__$",
+                        "typeString": "function (uint256)"
+                      }
+                    },
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+                    "isConstant": false,
+                    "isLValue": false,
+                    "isPure": false,
+                    "kind": "functionCall",
+                    "lValueRequested": false,
+                    "names": [],
+                    "nodeType": "FunctionCall",
+                    "src": "28944:45:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_tuple$__$",
+                      "typeString": "tuple()"
+                    }
+                  },
+                  "id": 1137,
+                  "nodeType": "ExpressionStatement",
+                  "src": "28944:45:1"
+                }
+              ]
+            },
+            "documentation": "@dev Internal function to burn a specific token.\nReverts if the token does not exist.\nDeprecated, use _burn(uint256) instead.\n@param owner owner of the token to burn\n@param tokenId uint256 ID of the token being burned",
+            "id": 1139,
+            "implemented": true,
+            "kind": "function",
+            "modifiers": [],
+            "name": "_burn",
+            "nodeType": "FunctionDefinition",
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+              "id": 1114,
+              "nodeType": "ParameterList",
+              "parameters": [
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+                  "constant": false,
+                  "id": 1111,
+                  "name": "owner",
+                  "nodeType": "VariableDeclaration",
+                  "scope": 1139,
+                  "src": "28647:13:1",
+                  "stateVariable": false,
+                  "storageLocation": "default",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_address",
+                    "typeString": "address"
+                  },
+                  "typeName": {
+                    "id": 1110,
+                    "name": "address",
+                    "nodeType": "ElementaryTypeName",
+                    "src": "28647:7:1",
+                    "stateMutability": "nonpayable",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_address",
+                      "typeString": "address"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                },
+                {
+                  "constant": false,
+                  "id": 1113,
+                  "name": "tokenId",
+                  "nodeType": "VariableDeclaration",
+                  "scope": 1139,
+                  "src": "28662:15:1",
+                  "stateVariable": false,
+                  "storageLocation": "default",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_uint256",
+                    "typeString": "uint256"
+                  },
+                  "typeName": {
+                    "id": 1112,
+                    "name": "uint256",
+                    "nodeType": "ElementaryTypeName",
+                    "src": "28662:7:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_uint256",
+                      "typeString": "uint256"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                }
+              ],
+              "src": "28646:32:1"
+            },
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+              "nodeType": "ParameterList",
+              "parameters": [],
+              "src": "28688:0:1"
+            },
+            "scope": 1302,
+            "src": "28632:364:1",
+            "stateMutability": "nonpayable",
+            "superFunction": 811,
+            "visibility": "internal"
+          },
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+            "body": {
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+              "nodeType": "Block",
+              "src": "29282:43:1",
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+                {
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+                    "baseExpression": {
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+                      "id": 1147,
+                      "name": "_ownedTokens",
+                      "nodeType": "Identifier",
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+                      "referencedDeclaration": 981,
+                      "src": "29299:12:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_mapping$_t_address_$_t_array$_t_uint256_$dyn_storage_$",
+                        "typeString": "mapping(address => uint256[] storage ref)"
+                      }
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+                      "id": 1148,
+                      "name": "owner",
+                      "nodeType": "Identifier",
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+                      "referencedDeclaration": 1141,
+                      "src": "29312:5:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_address",
+                        "typeString": "address"
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+                    "isLValue": true,
+                    "isPure": false,
+                    "lValueRequested": false,
+                    "nodeType": "IndexAccess",
+                    "src": "29299:19:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_array$_t_uint256_$dyn_storage",
+                      "typeString": "uint256[] storage ref"
+                    }
+                  },
+                  "functionReturnParameters": 1146,
+                  "id": 1150,
+                  "nodeType": "Return",
+                  "src": "29292:26:1"
+                }
+              ]
+            },
+            "documentation": "@dev Gets the list of token IDs of the requested owner.\n@param owner address owning the tokens\n@return uint256[] List of token IDs owned by the requested address",
+            "id": 1152,
+            "implemented": true,
+            "kind": "function",
+            "modifiers": [],
+            "name": "_tokensOfOwner",
+            "nodeType": "FunctionDefinition",
+            "parameters": {
+              "id": 1142,
+              "nodeType": "ParameterList",
+              "parameters": [
+                {
+                  "constant": false,
+                  "id": 1141,
+                  "name": "owner",
+                  "nodeType": "VariableDeclaration",
+                  "scope": 1152,
+                  "src": "29225:13:1",
+                  "stateVariable": false,
+                  "storageLocation": "default",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_address",
+                    "typeString": "address"
+                  },
+                  "typeName": {
+                    "id": 1140,
+                    "name": "address",
+                    "nodeType": "ElementaryTypeName",
+                    "src": "29225:7:1",
+                    "stateMutability": "nonpayable",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_address",
+                      "typeString": "address"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                }
+              ],
+              "src": "29224:15:1"
+            },
+            "returnParameters": {
+              "id": 1146,
+              "nodeType": "ParameterList",
+              "parameters": [
+                {
+                  "constant": false,
+                  "id": 1145,
+                  "name": "",
+                  "nodeType": "VariableDeclaration",
+                  "scope": 1152,
+                  "src": "29263:17:1",
+                  "stateVariable": false,
+                  "storageLocation": "storage",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_array$_t_uint256_$dyn_storage_ptr",
+                    "typeString": "uint256[]"
+                  },
+                  "typeName": {
+                    "baseType": {
+                      "id": 1143,
+                      "name": "uint256",
+                      "nodeType": "ElementaryTypeName",
+                      "src": "29263:7:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_uint256",
+                        "typeString": "uint256"
+                      }
+                    },
+                    "id": 1144,
+                    "length": null,
+                    "nodeType": "ArrayTypeName",
+                    "src": "29263:9:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_array$_t_uint256_$dyn_storage_ptr",
+                      "typeString": "uint256[]"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                }
+              ],
+              "src": "29262:19:1"
+            },
+            "scope": 1302,
+            "src": "29201:124:1",
+            "stateMutability": "view",
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+            "visibility": "internal"
+          },
+          {
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+              "nodeType": "Block",
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+                    "id": 1166,
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+                        "argumentTypes": null,
+                        "id": 1159,
+                        "name": "_ownedTokensIndex",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 985,
+                        "src": "29703:17:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_mapping$_t_uint256_$_t_uint256_$",
+                          "typeString": "mapping(uint256 => uint256)"
+                        }
+                      },
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+                        "id": 1160,
+                        "name": "tokenId",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 1156,
+                        "src": "29721:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
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+                      "isLValue": true,
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+                      "lValueRequested": true,
+                      "nodeType": "IndexAccess",
+                      "src": "29703:26:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_uint256",
+                        "typeString": "uint256"
+                      }
+                    },
+                    "nodeType": "Assignment",
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+                      "argumentTypes": null,
+                      "expression": {
+                        "argumentTypes": null,
+                        "baseExpression": {
+                          "argumentTypes": null,
+                          "id": 1162,
+                          "name": "_ownedTokens",
+                          "nodeType": "Identifier",
+                          "overloadedDeclarations": [],
+                          "referencedDeclaration": 981,
+                          "src": "29732:12:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_mapping$_t_address_$_t_array$_t_uint256_$dyn_storage_$",
+                            "typeString": "mapping(address => uint256[] storage ref)"
+                          }
+                        },
+                        "id": 1164,
+                        "indexExpression": {
+                          "argumentTypes": null,
+                          "id": 1163,
+                          "name": "to",
+                          "nodeType": "Identifier",
+                          "overloadedDeclarations": [],
+                          "referencedDeclaration": 1154,
+                          "src": "29745:2:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_address",
+                            "typeString": "address"
+                          }
+                        },
+                        "isConstant": false,
+                        "isLValue": true,
+                        "isPure": false,
+                        "lValueRequested": false,
+                        "nodeType": "IndexAccess",
+                        "src": "29732:16:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_array$_t_uint256_$dyn_storage",
+                          "typeString": "uint256[] storage ref"
+                        }
+                      },
+                      "id": 1165,
+                      "isConstant": false,
+                      "isLValue": true,
+                      "isPure": false,
+                      "lValueRequested": false,
+                      "memberName": "length",
+                      "nodeType": "MemberAccess",
+                      "referencedDeclaration": null,
+                      "src": "29732:23:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_uint256",
+                        "typeString": "uint256"
+                      }
+                    },
+                    "src": "29703:52:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_uint256",
+                      "typeString": "uint256"
+                    }
+                  },
+                  "id": 1167,
+                  "nodeType": "ExpressionStatement",
+                  "src": "29703:52:1"
+                },
+                {
+                  "expression": {
+                    "argumentTypes": null,
+                    "arguments": [
+                      {
+                        "argumentTypes": null,
+                        "id": 1172,
+                        "name": "tokenId",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 1156,
+                        "src": "29787:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      }
+                    ],
+                    "expression": {
+                      "argumentTypes": [
+                        {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      ],
+                      "expression": {
+                        "argumentTypes": null,
+                        "baseExpression": {
+                          "argumentTypes": null,
+                          "id": 1168,
+                          "name": "_ownedTokens",
+                          "nodeType": "Identifier",
+                          "overloadedDeclarations": [],
+                          "referencedDeclaration": 981,
+                          "src": "29765:12:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_mapping$_t_address_$_t_array$_t_uint256_$dyn_storage_$",
+                            "typeString": "mapping(address => uint256[] storage ref)"
+                          }
+                        },
+                        "id": 1170,
+                        "indexExpression": {
+                          "argumentTypes": null,
+                          "id": 1169,
+                          "name": "to",
+                          "nodeType": "Identifier",
+                          "overloadedDeclarations": [],
+                          "referencedDeclaration": 1154,
+                          "src": "29778:2:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_address",
+                            "typeString": "address"
+                          }
+                        },
+                        "isConstant": false,
+                        "isLValue": true,
+                        "isPure": false,
+                        "lValueRequested": false,
+                        "nodeType": "IndexAccess",
+                        "src": "29765:16:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_array$_t_uint256_$dyn_storage",
+                          "typeString": "uint256[] storage ref"
+                        }
+                      },
+                      "id": 1171,
+                      "isConstant": false,
+                      "isLValue": false,
+                      "isPure": false,
+                      "lValueRequested": false,
+                      "memberName": "push",
+                      "nodeType": "MemberAccess",
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+                              "isPure": false,
+                              "lValueRequested": false,
+                              "nodeType": "IndexAccess",
+                              "src": "31368:18:1",
+                              "typeDescriptions": {
+                                "typeIdentifier": "t_array$_t_uint256_$dyn_storage",
+                                "typeString": "uint256[] storage ref"
+                              }
+                            },
+                            "id": 1233,
+                            "indexExpression": {
+                              "argumentTypes": null,
+                              "id": 1231,
+                              "name": "tokenIndex",
+                              "nodeType": "Identifier",
+                              "overloadedDeclarations": [],
+                              "referencedDeclaration": 1213,
+                              "src": "31387:10:1",
+                              "typeDescriptions": {
+                                "typeIdentifier": "t_uint256",
+                                "typeString": "uint256"
+                              }
+                            },
+                            "isConstant": false,
+                            "isLValue": true,
+                            "isPure": false,
+                            "lValueRequested": true,
+                            "nodeType": "IndexAccess",
+                            "src": "31368:30:1",
+                            "typeDescriptions": {
+                              "typeIdentifier": "t_uint256",
+                              "typeString": "uint256"
+                            }
+                          },
+                          "nodeType": "Assignment",
+                          "operator": "=",
+                          "rightHandSide": {
+                            "argumentTypes": null,
+                            "id": 1234,
+                            "name": "lastTokenId",
+                            "nodeType": "Identifier",
+                            "overloadedDeclarations": [],
+                            "referencedDeclaration": 1222,
+                            "src": "31401:11:1",
+                            "typeDescriptions": {
+                              "typeIdentifier": "t_uint256",
+                              "typeString": "uint256"
+                            }
+                          },
+                          "src": "31368:44:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_uint256",
+                            "typeString": "uint256"
+                          }
+                        },
+                        "id": 1236,
+                        "nodeType": "ExpressionStatement",
+                        "src": "31368:44:1"
+                      },
+                      {
+                        "expression": {
+                          "argumentTypes": null,
+                          "id": 1241,
+                          "isConstant": false,
+                          "isLValue": false,
+                          "isPure": false,
+                          "lValueRequested": false,
+                          "leftHandSide": {
+                            "argumentTypes": null,
+                            "baseExpression": {
+                              "argumentTypes": null,
+                              "id": 1237,
+                              "name": "_ownedTokensIndex",
+                              "nodeType": "Identifier",
+                              "overloadedDeclarations": [],
+                              "referencedDeclaration": 985,
+                              "src": "31484:17:1",
+                              "typeDescriptions": {
+                                "typeIdentifier": "t_mapping$_t_uint256_$_t_uint256_$",
+                                "typeString": "mapping(uint256 => uint256)"
+                              }
+                            },
+                            "id": 1239,
+                            "indexExpression": {
+                              "argumentTypes": null,
+                              "id": 1238,
+                              "name": "lastTokenId",
+                              "nodeType": "Identifier",
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+                              "referencedDeclaration": 1222,
+                              "src": "31502:11:1",
+                              "typeDescriptions": {
+                                "typeIdentifier": "t_uint256",
+                                "typeString": "uint256"
+                              }
+                            },
+                            "isConstant": false,
+                            "isLValue": true,
+                            "isPure": false,
+                            "lValueRequested": true,
+                            "nodeType": "IndexAccess",
+                            "src": "31484:30:1",
+                            "typeDescriptions": {
+                              "typeIdentifier": "t_uint256",
+                              "typeString": "uint256"
+                            }
+                          },
+                          "nodeType": "Assignment",
+                          "operator": "=",
+                          "rightHandSide": {
+                            "argumentTypes": null,
+                            "id": 1240,
+                            "name": "tokenIndex",
+                            "nodeType": "Identifier",
+                            "overloadedDeclarations": [],
+                            "referencedDeclaration": 1213,
+                            "src": "31517:10:1",
+                            "typeDescriptions": {
+                              "typeIdentifier": "t_uint256",
+                              "typeString": "uint256"
+                            }
+                          },
+                          "src": "31484:43:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_uint256",
+                            "typeString": "uint256"
+                          }
+                        },
+                        "id": 1242,
+                        "nodeType": "ExpressionStatement",
+                        "src": "31484:43:1"
+                      }
+                    ]
+                  }
+                },
+                {
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+                    "id": 1249,
+                    "isConstant": false,
+                    "isLValue": false,
+                    "isPure": false,
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+                    "prefix": false,
+                    "src": "31658:27:1",
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+                      "expression": {
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+                        "baseExpression": {
+                          "argumentTypes": null,
+                          "id": 1245,
+                          "name": "_ownedTokens",
+                          "nodeType": "Identifier",
+                          "overloadedDeclarations": [],
+                          "referencedDeclaration": 981,
+                          "src": "31658:12:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_mapping$_t_address_$_t_array$_t_uint256_$dyn_storage_$",
+                            "typeString": "mapping(address => uint256[] storage ref)"
+                          }
+                        },
+                        "id": 1247,
+                        "indexExpression": {
+                          "argumentTypes": null,
+                          "id": 1246,
+                          "name": "from",
+                          "nodeType": "Identifier",
+                          "overloadedDeclarations": [],
+                          "referencedDeclaration": 1197,
+                          "src": "31671:4:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_address",
+                            "typeString": "address"
+                          }
+                        },
+                        "isConstant": false,
+                        "isLValue": true,
+                        "isPure": false,
+                        "lValueRequested": false,
+                        "nodeType": "IndexAccess",
+                        "src": "31658:18:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_array$_t_uint256_$dyn_storage",
+                          "typeString": "uint256[] storage ref"
+                        }
+                      },
+                      "id": 1248,
+                      "isConstant": false,
+                      "isLValue": true,
+                      "isPure": false,
+                      "lValueRequested": true,
+                      "memberName": "length",
+                      "nodeType": "MemberAccess",
+                      "referencedDeclaration": null,
+                      "src": "31658:25:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_uint256",
+                        "typeString": "uint256"
+                      }
+                    },
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+                      "typeIdentifier": "t_uint256",
+                      "typeString": "uint256"
+                    }
+                  },
+                  "id": 1250,
+                  "nodeType": "ExpressionStatement",
+                  "src": "31658:27:1"
+                }
+              ]
+            },
+            "documentation": "@dev Private function to remove a token from this extension's ownership-tracking data structures. Note that\nwhile the token is not assigned a new owner, the _ownedTokensIndex mapping is _not_ updated: this allows for\ngas optimizations e.g. when performing a transfer operation (avoiding double writes).\nThis has O(1) time complexity, but alters the order of the _ownedTokens array.\n@param from address representing the previous owner of the given token ID\n@param tokenId uint256 ID of the token to be removed from the tokens list of the given address",
+            "id": 1252,
+            "implemented": true,
+            "kind": "function",
+            "modifiers": [],
+            "name": "_removeTokenFromOwnerEnumeration",
+            "nodeType": "FunctionDefinition",
+            "parameters": {
+              "id": 1200,
+              "nodeType": "ParameterList",
+              "parameters": [
+                {
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+                  "id": 1197,
+                  "name": "from",
+                  "nodeType": "VariableDeclaration",
+                  "scope": 1252,
+                  "src": "30815:12:1",
+                  "stateVariable": false,
+                  "storageLocation": "default",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_address",
+                    "typeString": "address"
+                  },
+                  "typeName": {
+                    "id": 1196,
+                    "name": "address",
+                    "nodeType": "ElementaryTypeName",
+                    "src": "30815:7:1",
+                    "stateMutability": "nonpayable",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_address",
+                      "typeString": "address"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                },
+                {
+                  "constant": false,
+                  "id": 1199,
+                  "name": "tokenId",
+                  "nodeType": "VariableDeclaration",
+                  "scope": 1252,
+                  "src": "30829:15:1",
+                  "stateVariable": false,
+                  "storageLocation": "default",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_uint256",
+                    "typeString": "uint256"
+                  },
+                  "typeName": {
+                    "id": 1198,
+                    "name": "uint256",
+                    "nodeType": "ElementaryTypeName",
+                    "src": "30829:7:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_uint256",
+                      "typeString": "uint256"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                }
+              ],
+              "src": "30814:31:1"
+            },
+            "returnParameters": {
+              "id": 1201,
+              "nodeType": "ParameterList",
+              "parameters": [],
+              "src": "30854:0:1"
+            },
+            "scope": 1302,
+            "src": "30773:1128:1",
+            "stateMutability": "nonpayable",
+            "superFunction": null,
+            "visibility": "private"
+          },
+          {
+            "body": {
+              "id": 1300,
+              "nodeType": "Block",
+              "src": "32260:993:1",
+              "statements": [
+                {
+                  "assignments": [
+                    1258
+                  ],
+                  "declarations": [
+                    {
+                      "constant": false,
+                      "id": 1258,
+                      "name": "lastTokenIndex",
+                      "nodeType": "VariableDeclaration",
+                      "scope": 1300,
+                      "src": "32438:22:1",
+                      "stateVariable": false,
+                      "storageLocation": "default",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_uint256",
+                        "typeString": "uint256"
+                      },
+                      "typeName": {
+                        "id": 1257,
+                        "name": "uint256",
+                        "nodeType": "ElementaryTypeName",
+                        "src": "32438:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      },
+                      "value": null,
+                      "visibility": "internal"
+                    }
+                  ],
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+                  "initialValue": {
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+                    "arguments": [
+                      {
+                        "argumentTypes": null,
+                        "hexValue": "31",
+                        "id": 1262,
+                        "isConstant": false,
+                        "isLValue": false,
+                        "isPure": true,
+                        "kind": "number",
+                        "lValueRequested": false,
+                        "nodeType": "Literal",
+                        "src": "32485:1:1",
+                        "subdenomination": null,
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_rational_1_by_1",
+                          "typeString": "int_const 1"
+                        },
+                        "value": "1"
+                      }
+                    ],
+                    "expression": {
+                      "argumentTypes": [
+                        {
+                          "typeIdentifier": "t_rational_1_by_1",
+                          "typeString": "int_const 1"
+                        }
+                      ],
+                      "expression": {
+                        "argumentTypes": null,
+                        "expression": {
+                          "argumentTypes": null,
+                          "id": 1259,
+                          "name": "_allTokens",
+                          "nodeType": "Identifier",
+                          "overloadedDeclarations": [],
+                          "referencedDeclaration": 988,
+                          "src": "32463:10:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_array$_t_uint256_$dyn_storage",
+                            "typeString": "uint256[] storage ref"
+                          }
+                        },
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+                        "isConstant": false,
+                        "isLValue": true,
+                        "isPure": false,
+                        "lValueRequested": false,
+                        "memberName": "length",
+                        "nodeType": "MemberAccess",
+                        "referencedDeclaration": null,
+                        "src": "32463:17:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
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+                      "id": 1261,
+                      "isConstant": false,
+                      "isLValue": false,
+                      "isPure": false,
+                      "lValueRequested": false,
+                      "memberName": "sub",
+                      "nodeType": "MemberAccess",
+                      "referencedDeclaration": 190,
+                      "src": "32463:21:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_function_internal_pure$_t_uint256_$_t_uint256_$returns$_t_uint256_$bound_to$_t_uint256_$",
+                        "typeString": "function (uint256,uint256) pure returns (uint256)"
+                      }
+                    },
+                    "id": 1263,
+                    "isConstant": false,
+                    "isLValue": false,
+                    "isPure": false,
+                    "kind": "functionCall",
+                    "lValueRequested": false,
+                    "names": [],
+                    "nodeType": "FunctionCall",
+                    "src": "32463:24:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_uint256",
+                      "typeString": "uint256"
+                    }
+                  },
+                  "nodeType": "VariableDeclarationStatement",
+                  "src": "32438:49:1"
+                },
+                {
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+                  ],
+                  "declarations": [
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+                      "constant": false,
+                      "id": 1266,
+                      "name": "tokenIndex",
+                      "nodeType": "VariableDeclaration",
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+                      "src": "32497:18:1",
+                      "stateVariable": false,
+                      "storageLocation": "default",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_uint256",
+                        "typeString": "uint256"
+                      },
+                      "typeName": {
+                        "id": 1265,
+                        "name": "uint256",
+                        "nodeType": "ElementaryTypeName",
+                        "src": "32497:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      },
+                      "value": null,
+                      "visibility": "internal"
+                    }
+                  ],
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+                  "initialValue": {
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+                    "baseExpression": {
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+                      "id": 1267,
+                      "name": "_allTokensIndex",
+                      "nodeType": "Identifier",
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+                      "referencedDeclaration": 992,
+                      "src": "32518:15:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_mapping$_t_uint256_$_t_uint256_$",
+                        "typeString": "mapping(uint256 => uint256)"
+                      }
+                    },
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+                    "indexExpression": {
+                      "argumentTypes": null,
+                      "id": 1268,
+                      "name": "tokenId",
+                      "nodeType": "Identifier",
+                      "overloadedDeclarations": [],
+                      "referencedDeclaration": 1254,
+                      "src": "32534:7:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_uint256",
+                        "typeString": "uint256"
+                      }
+                    },
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+                    "isLValue": true,
+                    "isPure": false,
+                    "lValueRequested": false,
+                    "nodeType": "IndexAccess",
+                    "src": "32518:24:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_uint256",
+                      "typeString": "uint256"
+                    }
+                  },
+                  "nodeType": "VariableDeclarationStatement",
+                  "src": "32497:45:1"
+                },
+                {
+                  "assignments": [
+                    1272
+                  ],
+                  "declarations": [
+                    {
+                      "constant": false,
+                      "id": 1272,
+                      "name": "lastTokenId",
+                      "nodeType": "VariableDeclaration",
+                      "scope": 1300,
+                      "src": "32864:19:1",
+                      "stateVariable": false,
+                      "storageLocation": "default",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_uint256",
+                        "typeString": "uint256"
+                      },
+                      "typeName": {
+                        "id": 1271,
+                        "name": "uint256",
+                        "nodeType": "ElementaryTypeName",
+                        "src": "32864:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      },
+                      "value": null,
+                      "visibility": "internal"
+                    }
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+                    "baseExpression": {
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+                      "name": "_allTokens",
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+                      "src": "32886:10:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_array$_t_uint256_$dyn_storage",
+                        "typeString": "uint256[] storage ref"
+                      }
+                    },
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+                    "indexExpression": {
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+                      "id": 1274,
+                      "name": "lastTokenIndex",
+                      "nodeType": "Identifier",
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+                      "src": "32897:14:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_uint256",
+                        "typeString": "uint256"
+                      }
+                    },
+                    "isConstant": false,
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+                    "isPure": false,
+                    "lValueRequested": false,
+                    "nodeType": "IndexAccess",
+                    "src": "32886:26:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_uint256",
+                      "typeString": "uint256"
+                    }
+                  },
+                  "nodeType": "VariableDeclarationStatement",
+                  "src": "32864:48:1"
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+                        "name": "_allTokens",
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+                        "src": "32923:10:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_array$_t_uint256_$dyn_storage",
+                          "typeString": "uint256[] storage ref"
+                        }
+                      },
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+                      "indexExpression": {
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+                        "name": "tokenIndex",
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+                        "src": "32934:10:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
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+                        "typeIdentifier": "t_uint256",
+                        "typeString": "uint256"
+                      }
+                    },
+                    "nodeType": "Assignment",
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+                      "name": "lastTokenId",
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+                      "src": "32948:11:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_uint256",
+                        "typeString": "uint256"
+                      }
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+                    "src": "32923:36:1",
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+                    }
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+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 992,
+                        "src": "33027:15:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_mapping$_t_uint256_$_t_uint256_$",
+                          "typeString": "mapping(uint256 => uint256)"
+                        }
+                      },
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+                        "name": "lastTokenId",
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+                        "src": "33043:11:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
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+                        "src": "33189:10:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_array$_t_uint256_$dyn_storage",
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+                        "referencedDeclaration": 882,
+                        "src": "23642:4:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        }
+                      },
+                      {
+                        "argumentTypes": null,
+                        "id": 910,
+                        "name": "tokenId",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 886,
+                        "src": "23648:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      },
+                      {
+                        "argumentTypes": null,
+                        "id": 911,
+                        "name": "_data",
+                        "nodeType": "Identifier",
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+                        "referencedDeclaration": 888,
+                        "src": "23657:5:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_bytes_memory_ptr",
+                          "typeString": "bytes memory"
+                        }
+                      }
+                    ],
+                    "expression": {
+                      "argumentTypes": [
+                        {
+                          "typeIdentifier": "t_address_payable",
+                          "typeString": "address payable"
+                        },
+                        {
+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        },
+                        {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        },
+                        {
+                          "typeIdentifier": "t_bytes_memory_ptr",
+                          "typeString": "bytes memory"
+                        }
+                      ],
+                      "expression": {
+                        "argumentTypes": null,
+                        "arguments": [
+                          {
+                            "argumentTypes": null,
+                            "id": 904,
+                            "name": "to",
+                            "nodeType": "Identifier",
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+                            "referencedDeclaration": 884,
+                            "src": "23609:2:1",
+                            "typeDescriptions": {
+                              "typeIdentifier": "t_address",
+                              "typeString": "address"
+                            }
+                          }
+                        ],
+                        "expression": {
+                          "argumentTypes": [
+                            {
+                              "typeIdentifier": "t_address",
+                              "typeString": "address"
+                            }
+                          ],
+                          "id": 903,
+                          "name": "IERC721Receiver",
+                          "nodeType": "Identifier",
+                          "overloadedDeclarations": [],
+                          "referencedDeclaration": 139,
+                          "src": "23593:15:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_type$_t_contract$_IERC721Receiver_$139_$",
+                            "typeString": "type(contract IERC721Receiver)"
+                          }
+                        },
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+                        "isLValue": false,
+                        "isPure": false,
+                        "kind": "typeConversion",
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+                        "names": [],
+                        "nodeType": "FunctionCall",
+                        "src": "23593:19:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_contract$_IERC721Receiver_$139",
+                          "typeString": "contract IERC721Receiver"
+                        }
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+                      "isLValue": false,
+                      "isPure": false,
+                      "lValueRequested": false,
+                      "memberName": "onERC721Received",
+                      "nodeType": "MemberAccess",
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+                      "src": "23593:36:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_function_external_nonpayable$_t_address_$_t_address_$_t_uint256_$_t_bytes_memory_ptr_$returns$_t_bytes4_$",
+                        "typeString": "function (address,address,uint256,bytes memory) external returns (bytes4)"
+                      }
+                    },
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+                    "isConstant": false,
+                    "isLValue": false,
+                    "isPure": false,
+                    "kind": "functionCall",
+                    "lValueRequested": false,
+                    "names": [],
+                    "nodeType": "FunctionCall",
+                    "src": "23593:70:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_bytes4",
+                      "typeString": "bytes4"
+                    }
+                  },
+                  "nodeType": "VariableDeclarationStatement",
+                  "src": "23577:86:1"
+                },
+                {
+                  "expression": {
+                    "argumentTypes": null,
+                    "components": [
+                      {
+                        "argumentTypes": null,
+                        "commonType": {
+                          "typeIdentifier": "t_bytes4",
+                          "typeString": "bytes4"
+                        },
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+                        "isPure": false,
+                        "lValueRequested": false,
+                        "leftExpression": {
+                          "argumentTypes": null,
+                          "id": 914,
+                          "name": "retval",
+                          "nodeType": "Identifier",
+                          "overloadedDeclarations": [],
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+                          "src": "23681:6:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_bytes4",
+                            "typeString": "bytes4"
+                          }
+                        },
+                        "nodeType": "BinaryOperation",
+                        "operator": "==",
+                        "rightExpression": {
+                          "argumentTypes": null,
+                          "id": 915,
+                          "name": "_ERC721_RECEIVED",
+                          "nodeType": "Identifier",
+                          "overloadedDeclarations": [],
+                          "referencedDeclaration": 403,
+                          "src": "23691:16:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_bytes4",
+                            "typeString": "bytes4"
+                          }
+                        },
+                        "src": "23681:26:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_bool",
+                          "typeString": "bool"
+                        }
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+                  "nodeType": "Return",
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+                }
+              ]
+            },
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+                  "visibility": "internal"
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+                    "src": "23426:7:1",
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+                      "typeIdentifier": "t_uint256",
+                      "typeString": "uint256"
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+                  "value": null,
+                  "visibility": "internal"
+                },
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+                  "src": "23443:18:1",
+                  "stateVariable": false,
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+                    "name": "bytes",
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+                    "src": "23443:5:1",
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+                      "typeIdentifier": "t_bytes_storage_ptr",
+                      "typeString": "bytes"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                }
+              ],
+              "src": "23399:63:1"
+            },
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+              "nodeType": "ParameterList",
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+                  "id": 891,
+                  "name": "",
+                  "nodeType": "VariableDeclaration",
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+                  "src": "23489:4:1",
+                  "stateVariable": false,
+                  "storageLocation": "default",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_bool",
+                    "typeString": "bool"
+                  },
+                  "typeName": {
+                    "id": 890,
+                    "name": "bool",
+                    "nodeType": "ElementaryTypeName",
+                    "src": "23489:4:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_bool",
+                      "typeString": "bool"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                }
+              ],
+              "src": "23488:6:1"
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+            "src": "23368:347:1",
+            "stateMutability": "nonpayable",
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+              "nodeType": "Block",
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+                    "commonType": {
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+                      "baseExpression": {
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+                        "id": 925,
+                        "name": "_tokenApprovals",
+                        "nodeType": "Identifier",
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+                        "referencedDeclaration": 411,
+                        "src": "23940:15:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_mapping$_t_uint256_$_t_address_$",
+                          "typeString": "mapping(uint256 => address)"
+                        }
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+                        "id": 926,
+                        "name": "tokenId",
+                        "nodeType": "Identifier",
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+                        "referencedDeclaration": 922,
+                        "src": "23956:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
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+                        "typeString": "address"
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+                    },
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+                      "arguments": [
+                        {
+                          "argumentTypes": null,
+                          "hexValue": "30",
+                          "id": 929,
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+                          "isLValue": false,
+                          "isPure": true,
+                          "kind": "number",
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+                          "nodeType": "Literal",
+                          "src": "23976:1:1",
+                          "subdenomination": null,
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_rational_0_by_1",
+                            "typeString": "int_const 0"
+                          },
+                          "value": "0"
+                        }
+                      ],
+                      "expression": {
+                        "argumentTypes": [
+                          {
+                            "typeIdentifier": "t_rational_0_by_1",
+                            "typeString": "int_const 0"
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+                        "isConstant": false,
+                        "isLValue": false,
+                        "isPure": true,
+                        "lValueRequested": false,
+                        "nodeType": "ElementaryTypeNameExpression",
+                        "src": "23968:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_type$_t_address_$",
+                          "typeString": "type(address)"
+                        },
+                        "typeName": "address"
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+                      "isPure": true,
+                      "kind": "typeConversion",
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+                      "names": [],
+                      "nodeType": "FunctionCall",
+                      "src": "23968:10:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_address_payable",
+                        "typeString": "address payable"
+                      }
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+                    "src": "23940:38:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_bool",
+                      "typeString": "bool"
+                    }
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+                  "nodeType": "IfStatement",
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+                    "nodeType": "Block",
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+                          "id": 938,
+                          "isConstant": false,
+                          "isLValue": false,
+                          "isPure": false,
+                          "lValueRequested": false,
+                          "leftHandSide": {
+                            "argumentTypes": null,
+                            "baseExpression": {
+                              "argumentTypes": null,
+                              "id": 932,
+                              "name": "_tokenApprovals",
+                              "nodeType": "Identifier",
+                              "overloadedDeclarations": [],
+                              "referencedDeclaration": 411,
+                              "src": "23994:15:1",
+                              "typeDescriptions": {
+                                "typeIdentifier": "t_mapping$_t_uint256_$_t_address_$",
+                                "typeString": "mapping(uint256 => address)"
+                              }
+                            },
+                            "id": 934,
+                            "indexExpression": {
+                              "argumentTypes": null,
+                              "id": 933,
+                              "name": "tokenId",
+                              "nodeType": "Identifier",
+                              "overloadedDeclarations": [],
+                              "referencedDeclaration": 922,
+                              "src": "24010:7:1",
+                              "typeDescriptions": {
+                                "typeIdentifier": "t_uint256",
+                                "typeString": "uint256"
+                              }
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+                            "isConstant": false,
+                            "isLValue": true,
+                            "isPure": false,
+                            "lValueRequested": true,
+                            "nodeType": "IndexAccess",
+                            "src": "23994:24:1",
+                            "typeDescriptions": {
+                              "typeIdentifier": "t_address",
+                              "typeString": "address"
+                            }
+                          },
+                          "nodeType": "Assignment",
+                          "operator": "=",
+                          "rightHandSide": {
+                            "argumentTypes": null,
+                            "arguments": [
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+                                "argumentTypes": null,
+                                "hexValue": "30",
+                                "id": 936,
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+                                "isLValue": false,
+                                "isPure": true,
+                                "kind": "number",
+                                "lValueRequested": false,
+                                "nodeType": "Literal",
+                                "src": "24029:1:1",
+                                "subdenomination": null,
+                                "typeDescriptions": {
+                                  "typeIdentifier": "t_rational_0_by_1",
+                                  "typeString": "int_const 0"
+                                },
+                                "value": "0"
+                              }
+                            ],
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+                              "argumentTypes": [
+                                {
+                                  "typeIdentifier": "t_rational_0_by_1",
+                                  "typeString": "int_const 0"
+                                }
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+                              "isConstant": false,
+                              "isLValue": false,
+                              "isPure": true,
+                              "lValueRequested": false,
+                              "nodeType": "ElementaryTypeNameExpression",
+                              "src": "24021:7:1",
+                              "typeDescriptions": {
+                                "typeIdentifier": "t_type$_t_address_$",
+                                "typeString": "type(address)"
+                              },
+                              "typeName": "address"
+                            },
+                            "id": 937,
+                            "isConstant": false,
+                            "isLValue": false,
+                            "isPure": true,
+                            "kind": "typeConversion",
+                            "lValueRequested": false,
+                            "names": [],
+                            "nodeType": "FunctionCall",
+                            "src": "24021:10:1",
+                            "typeDescriptions": {
+                              "typeIdentifier": "t_address_payable",
+                              "typeString": "address payable"
+                            }
+                          },
+                          "src": "23994:37:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_address",
+                            "typeString": "address"
+                          }
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+                        "id": 939,
+                        "nodeType": "ExpressionStatement",
+                        "src": "23994:37:1"
+                      }
+                    ]
+                  }
+                }
+              ]
+            },
+            "documentation": "@dev Private function to clear current approval of a given token ID.\n@param tokenId uint256 ID of the token to be transferred",
+            "id": 943,
+            "implemented": true,
+            "kind": "function",
+            "modifiers": [],
+            "name": "_clearApproval",
+            "nodeType": "FunctionDefinition",
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+              "nodeType": "ParameterList",
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+                  "nodeType": "VariableDeclaration",
+                  "scope": 943,
+                  "src": "23901:15:1",
+                  "stateVariable": false,
+                  "storageLocation": "default",
+                  "typeDescriptions": {
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+                    "name": "uint256",
+                    "nodeType": "ElementaryTypeName",
+                    "src": "23901:7:1",
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+                      "typeString": "uint256"
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+                  "visibility": "internal"
+                }
+              ],
+              "src": "23900:17:1"
+            },
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+              "src": "23926:0:1"
+            },
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+            "src": "23877:171:1",
+            "stateMutability": "nonpayable",
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+            "visibility": "private"
+          }
+        ],
+        "scope": 1469,
+        "src": "11949:12101:1"
+      },
+      {
+        "id": 945,
+        "literals": [
+          "solidity",
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+          ".0"
+        ],
+        "nodeType": "PragmaDirective",
+        "src": "24121:23:1"
+      },
+      {
+        "baseContracts": [
+          {
+            "arguments": null,
+            "baseName": {
+              "contractScope": null,
+              "id": 946,
+              "name": "IERC721",
+              "nodeType": "UserDefinedTypeName",
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+              "src": "24314:7:1",
+              "typeDescriptions": {
+                "typeIdentifier": "t_contract$_IERC721_$124",
+                "typeString": "contract IERC721"
+              }
+            },
+            "id": 947,
+            "nodeType": "InheritanceSpecifier",
+            "src": "24314:7:1"
+          }
+        ],
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+        ],
+        "contractKind": "contract",
+        "documentation": "@title ERC-721 Non-Fungible Token Standard, optional enumeration extension\n@dev See https://eips.ethereum.org/EIPS/eip-721",
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+        "id": 969,
+        "linearizedBaseContracts": [
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+          23
+        ],
+        "name": "IERC721Enumerable",
+        "nodeType": "ContractDefinition",
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+            "documentation": null,
+            "id": 952,
+            "implemented": false,
+            "kind": "function",
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+            "name": "totalSupply",
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+                          "typeIdentifier": "t_mapping$_t_address_$_t_array$_t_uint256_$dyn_storage_$",
+                          "typeString": "mapping(address => uint256[] storage ref)"
+                        }
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+                        "name": "owner",
+                        "nodeType": "Identifier",
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+                        "src": "26489:5:1",
+                        "typeDescriptions": {
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+                          "typeString": "address"
+                        }
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+                      "nodeType": "IndexAccess",
+                      "src": "26476:19:1",
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+                        "typeString": "uint256[] storage ref"
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+                      "id": 1024,
+                      "name": "index",
+                      "nodeType": "Identifier",
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+                      "src": "26496:5:1",
+                      "typeDescriptions": {
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+                  "storageLocation": "default",
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+                    "typeString": "address"
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+                    "name": "address",
+                    "nodeType": "ElementaryTypeName",
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+                    "stateMutability": "nonpayable",
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+                      "typeString": "address"
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+                      "name": "_allTokens",
+                      "nodeType": "Identifier",
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+                      "src": "26732:10:1",
+                      "typeDescriptions": {
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+                    "memberName": "length",
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+                    "src": "26732:17:1",
+                    "typeDescriptions": {
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+                      "typeString": "uint256"
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+                  "nodeType": "Return",
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+                }
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+            },
+            "documentation": "@dev Gets the total amount of tokens stored by the contract.\n@return uint256 representing the total amount of tokens",
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+            "implemented": true,
+            "kind": "function",
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+            "name": "totalSupply",
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+                  "storageLocation": "default",
+                  "typeDescriptions": {
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+                    "typeString": "uint256"
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+                    "name": "uint256",
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+                      "typeString": "uint256"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                }
+              ],
+              "src": "26705:9:1"
+            },
+            "scope": 1302,
+            "src": "26662:94:1",
+            "stateMutability": "view",
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+            "visibility": "public"
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+                        "commonType": {
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+                          "typeString": "uint256"
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+                        "isLValue": false,
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+                        "lValueRequested": false,
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+                          "id": 1045,
+                          "name": "index",
+                          "nodeType": "Identifier",
+                          "overloadedDeclarations": [],
+                          "referencedDeclaration": 1039,
+                          "src": "27179:5:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_uint256",
+                            "typeString": "uint256"
+                          }
+                        },
+                        "nodeType": "BinaryOperation",
+                        "operator": "<",
+                        "rightExpression": {
+                          "argumentTypes": null,
+                          "arguments": [],
+                          "expression": {
+                            "argumentTypes": [],
+                            "id": 1046,
+                            "name": "totalSupply",
+                            "nodeType": "Identifier",
+                            "overloadedDeclarations": [
+                              1037
+                            ],
+                            "referencedDeclaration": 1037,
+                            "src": "27187:11:1",
+                            "typeDescriptions": {
+                              "typeIdentifier": "t_function_internal_view$__$returns$_t_uint256_$",
+                              "typeString": "function () view returns (uint256)"
+                            }
+                          },
+                          "id": 1047,
+                          "isConstant": false,
+                          "isLValue": false,
+                          "isPure": false,
+                          "kind": "functionCall",
+                          "lValueRequested": false,
+                          "names": [],
+                          "nodeType": "FunctionCall",
+                          "src": "27187:13:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_uint256",
+                            "typeString": "uint256"
+                          }
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+                        "src": "27179:21:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_bool",
+                          "typeString": "bool"
+                        }
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+                        "isConstant": false,
+                        "isLValue": false,
+                        "isPure": true,
+                        "kind": "string",
+                        "lValueRequested": false,
+                        "nodeType": "Literal",
+                        "src": "27202:46:1",
+                        "subdenomination": null,
+                        "typeDescriptions": {
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+                          "typeString": "literal_string \"ERC721Enumerable: global index out of bounds\""
+                        },
+                        "value": "ERC721Enumerable: global index out of bounds"
+                      }
+                    ],
+                    "expression": {
+                      "argumentTypes": [
+                        {
+                          "typeIdentifier": "t_bool",
+                          "typeString": "bool"
+                        },
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+                        1544
+                      ],
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+                      "src": "27171:7:1",
+                      "typeDescriptions": {
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+                        "typeString": "function (bool,string memory) pure"
+                      }
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+                    "id": 1050,
+                    "isConstant": false,
+                    "isLValue": false,
+                    "isPure": false,
+                    "kind": "functionCall",
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+                      "typeString": "tuple()"
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+                      "id": 1052,
+                      "name": "_allTokens",
+                      "nodeType": "Identifier",
+                      "overloadedDeclarations": [],
+                      "referencedDeclaration": 988,
+                      "src": "27266:10:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_array$_t_uint256_$dyn_storage",
+                        "typeString": "uint256[] storage ref"
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+                    "id": 1054,
+                    "indexExpression": {
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+                      "id": 1053,
+                      "name": "index",
+                      "nodeType": "Identifier",
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+                      "referencedDeclaration": 1039,
+                      "src": "27277:5:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_uint256",
+                        "typeString": "uint256"
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+                    "lValueRequested": false,
+                    "nodeType": "IndexAccess",
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+                      "typeString": "uint256"
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+                  "src": "27259:24:1"
+                }
+              ]
+            },
+            "documentation": "@dev Gets the token ID at a given index of all the tokens in this contract\nReverts if the index is greater or equal to the total number of tokens.\n@param index uint256 representing the index to be accessed of the tokens list\n@return uint256 token ID at the given index of the tokens list",
+            "id": 1057,
+            "implemented": true,
+            "kind": "function",
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+                  "name": "index",
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+                  "stateVariable": false,
+                  "storageLocation": "default",
+                  "typeDescriptions": {
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+                    "typeString": "uint256"
+                  },
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+                    "name": "uint256",
+                    "nodeType": "ElementaryTypeName",
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+                    "typeDescriptions": {
+                      "typeIdentifier": "t_uint256",
+                      "typeString": "uint256"
+                    }
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+                  "value": null,
+                  "visibility": "internal"
+                }
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+                  "nodeType": "VariableDeclaration",
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+                  "src": "27152:7:1",
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+                  "storageLocation": "default",
+                  "typeDescriptions": {
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+                    "typeString": "uint256"
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+                        "name": "from",
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+                        "src": "27770:4:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        }
+                      },
+                      {
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+                        "id": 1070,
+                        "name": "to",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 1061,
+                        "src": "27776:2:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        }
+                      },
+                      {
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+                        "id": 1071,
+                        "name": "tokenId",
+                        "nodeType": "Identifier",
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+                        "referencedDeclaration": 1063,
+                        "src": "27780:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      }
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+                      "argumentTypes": [
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+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
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+                        {
+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        },
+                        {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
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+                        "name": "super",
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+                        "src": "27750:5:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_super$_ERC721Enumerable_$1302",
+                          "typeString": "contract super ERC721Enumerable"
+                        }
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+                        "name": "from",
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+                        "src": "27832:4:1",
+                        "typeDescriptions": {
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+                          "typeString": "address"
+                        }
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+                      {
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+                        "id": 1076,
+                        "name": "tokenId",
+                        "nodeType": "Identifier",
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+                        "referencedDeclaration": 1063,
+                        "src": "27838:7:1",
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+                          "typeString": "uint256"
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+                          "typeString": "address"
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+                        {
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+                          "typeString": "uint256"
+                        }
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+                        "referencedDeclaration": 1061,
+                        "src": "27885:2:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        }
+                      },
+                      {
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+                        "id": 1081,
+                        "name": "tokenId",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 1063,
+                        "src": "27889:7:1",
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+                          "typeString": "address"
+                        },
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+                          "typeString": "uint256"
+                        }
+                      ],
+                      "id": 1079,
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+                      "nodeType": "Identifier",
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+                      "src": "27857:27:1",
+                      "typeDescriptions": {
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+                        "typeString": "function (address,uint256)"
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+                }
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+                  "storageLocation": "default",
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+                    "typeIdentifier": "t_address",
+                    "typeString": "address"
+                  },
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+                    "name": "address",
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+                    "src": "27688:7:1",
+                    "stateMutability": "nonpayable",
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+                      "typeIdentifier": "t_address",
+                      "typeString": "address"
+                    }
+                  },
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+                  "visibility": "internal"
+                },
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+                  "constant": false,
+                  "id": 1061,
+                  "name": "to",
+                  "nodeType": "VariableDeclaration",
+                  "scope": 1085,
+                  "src": "27702:10:1",
+                  "stateVariable": false,
+                  "storageLocation": "default",
+                  "typeDescriptions": {
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+                    "typeString": "address"
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+                    "name": "address",
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+                    "src": "27702:7:1",
+                    "stateMutability": "nonpayable",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_address",
+                      "typeString": "address"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                },
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+                  "constant": false,
+                  "id": 1063,
+                  "name": "tokenId",
+                  "nodeType": "VariableDeclaration",
+                  "scope": 1085,
+                  "src": "27714:15:1",
+                  "stateVariable": false,
+                  "storageLocation": "default",
+                  "typeDescriptions": {
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+                    "typeString": "uint256"
+                  },
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+                    "id": 1062,
+                    "name": "uint256",
+                    "nodeType": "ElementaryTypeName",
+                    "src": "27714:7:1",
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+                      "typeIdentifier": "t_uint256",
+                      "typeString": "uint256"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                }
+              ],
+              "src": "27687:43:1"
+            },
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+              "nodeType": "ParameterList",
+              "parameters": [],
+              "src": "27740:0:1"
+            },
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+            "src": "27665:239:1",
+            "stateMutability": "nonpayable",
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+            "visibility": "internal"
+          },
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+              "nodeType": "Block",
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+                        "referencedDeclaration": 1087,
+                        "src": "28236:2:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        }
+                      },
+                      {
+                        "argumentTypes": null,
+                        "id": 1096,
+                        "name": "tokenId",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 1089,
+                        "src": "28240:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      }
+                    ],
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+                      "argumentTypes": [
+                        {
+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        },
+                        {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      ],
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+                        "id": 1092,
+                        "name": "super",
+                        "nodeType": "Identifier",
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+                        "referencedDeclaration": 1572,
+                        "src": "28224:5:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_super$_ERC721Enumerable_$1302",
+                          "typeString": "contract super ERC721Enumerable"
+                        }
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+                      "isConstant": false,
+                      "isLValue": false,
+                      "isPure": false,
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+                      "memberName": "_mint",
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+                      "src": "28224:11:1",
+                      "typeDescriptions": {
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+                        "typeString": "function (address,uint256)"
+                      }
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+                    "isLValue": false,
+                    "isPure": false,
+                    "kind": "functionCall",
+                    "lValueRequested": false,
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+                    "src": "28224:24:1",
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+                      "typeString": "tuple()"
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+                        "id": 1100,
+                        "name": "to",
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+                        "referencedDeclaration": 1087,
+                        "src": "28287:2:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        }
+                      },
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+                        "argumentTypes": null,
+                        "id": 1101,
+                        "name": "tokenId",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 1089,
+                        "src": "28291:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
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+                    ],
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+                        {
+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        },
+                        {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      ],
+                      "id": 1099,
+                      "name": "_addTokenToOwnerEnumeration",
+                      "nodeType": "Identifier",
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+                      "src": "28259:27:1",
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+                        "typeString": "function (address,uint256)"
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+                    "src": "28259:40:1",
+                    "typeDescriptions": {
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+                      "typeString": "tuple()"
+                    }
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+                  "src": "28259:40:1"
+                },
+                {
+                  "expression": {
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+                    "arguments": [
+                      {
+                        "argumentTypes": null,
+                        "id": 1105,
+                        "name": "tokenId",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 1089,
+                        "src": "28342:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      }
+                    ],
+                    "expression": {
+                      "argumentTypes": [
+                        {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      ],
+                      "id": 1104,
+                      "name": "_addTokenToAllTokensEnumeration",
+                      "nodeType": "Identifier",
+                      "overloadedDeclarations": [],
+                      "referencedDeclaration": 1195,
+                      "src": "28310:31:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_function_internal_nonpayable$_t_uint256_$returns$__$",
+                        "typeString": "function (uint256)"
+                      }
+                    },
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+                    "isConstant": false,
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+                    "isPure": false,
+                    "kind": "functionCall",
+                    "lValueRequested": false,
+                    "names": [],
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+                    "src": "28310:40:1",
+                    "typeDescriptions": {
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+                      "typeString": "tuple()"
+                    }
+                  },
+                  "id": 1107,
+                  "nodeType": "ExpressionStatement",
+                  "src": "28310:40:1"
+                }
+              ]
+            },
+            "documentation": "@dev Internal function to mint a new token.\nReverts if the given token ID already exists.\n@param to address the beneficiary that will own the minted token\n@param tokenId uint256 ID of the token to be minted",
+            "id": 1109,
+            "implemented": true,
+            "kind": "function",
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+            "name": "_mint",
+            "nodeType": "FunctionDefinition",
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+              "nodeType": "ParameterList",
+              "parameters": [
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+                  "id": 1087,
+                  "name": "to",
+                  "nodeType": "VariableDeclaration",
+                  "scope": 1109,
+                  "src": "28176:10:1",
+                  "stateVariable": false,
+                  "storageLocation": "default",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_address",
+                    "typeString": "address"
+                  },
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+                    "name": "address",
+                    "nodeType": "ElementaryTypeName",
+                    "src": "28176:7:1",
+                    "stateMutability": "nonpayable",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_address",
+                      "typeString": "address"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                },
+                {
+                  "constant": false,
+                  "id": 1089,
+                  "name": "tokenId",
+                  "nodeType": "VariableDeclaration",
+                  "scope": 1109,
+                  "src": "28188:15:1",
+                  "stateVariable": false,
+                  "storageLocation": "default",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_uint256",
+                    "typeString": "uint256"
+                  },
+                  "typeName": {
+                    "id": 1088,
+                    "name": "uint256",
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+                    "src": "28188:7:1",
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+                      "typeString": "uint256"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                }
+              ],
+              "src": "28175:29:1"
+            },
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+              "nodeType": "ParameterList",
+              "parameters": [],
+              "src": "28214:0:1"
+            },
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+            "src": "28161:196:1",
+            "stateMutability": "nonpayable",
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+            "visibility": "internal"
+          },
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+              "src": "28688:308:1",
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+                    "arguments": [
+                      {
+                        "argumentTypes": null,
+                        "id": 1119,
+                        "name": "owner",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 1111,
+                        "src": "28710:5:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        }
+                      },
+                      {
+                        "argumentTypes": null,
+                        "id": 1120,
+                        "name": "tokenId",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 1113,
+                        "src": "28717:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      }
+                    ],
+                    "expression": {
+                      "argumentTypes": [
+                        {
+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        },
+                        {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      ],
+                      "expression": {
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+                        "id": 1116,
+                        "name": "super",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 1572,
+                        "src": "28698:5:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_super$_ERC721Enumerable_$1302",
+                          "typeString": "contract super ERC721Enumerable"
+                        }
+                      },
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+                      "isConstant": false,
+                      "isLValue": false,
+                      "isPure": false,
+                      "lValueRequested": false,
+                      "memberName": "_burn",
+                      "nodeType": "MemberAccess",
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+                      "src": "28698:11:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_function_internal_nonpayable$_t_address_$_t_uint256_$returns$__$",
+                        "typeString": "function (address,uint256)"
+                      }
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+                    "isLValue": false,
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+                    "kind": "functionCall",
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+                      "typeString": "tuple()"
+                    }
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+                  "src": "28698:27:1"
+                },
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+                    "arguments": [
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+                        "argumentTypes": null,
+                        "id": 1124,
+                        "name": "owner",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 1111,
+                        "src": "28769:5:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        }
+                      },
+                      {
+                        "argumentTypes": null,
+                        "id": 1125,
+                        "name": "tokenId",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 1113,
+                        "src": "28776:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      }
+                    ],
+                    "expression": {
+                      "argumentTypes": [
+                        {
+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        },
+                        {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      ],
+                      "id": 1123,
+                      "name": "_removeTokenFromOwnerEnumeration",
+                      "nodeType": "Identifier",
+                      "overloadedDeclarations": [],
+                      "referencedDeclaration": 1252,
+                      "src": "28736:32:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_function_internal_nonpayable$_t_address_$_t_uint256_$returns$__$",
+                        "typeString": "function (address,uint256)"
+                      }
+                    },
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+                    "isConstant": false,
+                    "isLValue": false,
+                    "isPure": false,
+                    "kind": "functionCall",
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+                    "src": "28736:48:1",
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+                      "typeString": "tuple()"
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+                  "nodeType": "ExpressionStatement",
+                  "src": "28736:48:1"
+                },
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+                    "id": 1132,
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+                    "isLValue": false,
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+                    "lValueRequested": false,
+                    "leftHandSide": {
+                      "argumentTypes": null,
+                      "baseExpression": {
+                        "argumentTypes": null,
+                        "id": 1128,
+                        "name": "_ownedTokensIndex",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 985,
+                        "src": "28903:17:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_mapping$_t_uint256_$_t_uint256_$",
+                          "typeString": "mapping(uint256 => uint256)"
+                        }
+                      },
+                      "id": 1130,
+                      "indexExpression": {
+                        "argumentTypes": null,
+                        "id": 1129,
+                        "name": "tokenId",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 1113,
+                        "src": "28921:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      },
+                      "isConstant": false,
+                      "isLValue": true,
+                      "isPure": false,
+                      "lValueRequested": true,
+                      "nodeType": "IndexAccess",
+                      "src": "28903:26:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_uint256",
+                        "typeString": "uint256"
+                      }
+                    },
+                    "nodeType": "Assignment",
+                    "operator": "=",
+                    "rightHandSide": {
+                      "argumentTypes": null,
+                      "hexValue": "30",
+                      "id": 1131,
+                      "isConstant": false,
+                      "isLValue": false,
+                      "isPure": true,
+                      "kind": "number",
+                      "lValueRequested": false,
+                      "nodeType": "Literal",
+                      "src": "28932:1:1",
+                      "subdenomination": null,
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_rational_0_by_1",
+                        "typeString": "int_const 0"
+                      },
+                      "value": "0"
+                    },
+                    "src": "28903:30:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_uint256",
+                      "typeString": "uint256"
+                    }
+                  },
+                  "id": 1133,
+                  "nodeType": "ExpressionStatement",
+                  "src": "28903:30:1"
+                },
+                {
+                  "expression": {
+                    "argumentTypes": null,
+                    "arguments": [
+                      {
+                        "argumentTypes": null,
+                        "id": 1135,
+                        "name": "tokenId",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 1113,
+                        "src": "28981:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      }
+                    ],
+                    "expression": {
+                      "argumentTypes": [
+                        {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      ],
+                      "id": 1134,
+                      "name": "_removeTokenFromAllTokensEnumeration",
+                      "nodeType": "Identifier",
+                      "overloadedDeclarations": [],
+                      "referencedDeclaration": 1301,
+                      "src": "28944:36:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_function_internal_nonpayable$_t_uint256_$returns$__$",
+                        "typeString": "function (uint256)"
+                      }
+                    },
+                    "id": 1136,
+                    "isConstant": false,
+                    "isLValue": false,
+                    "isPure": false,
+                    "kind": "functionCall",
+                    "lValueRequested": false,
+                    "names": [],
+                    "nodeType": "FunctionCall",
+                    "src": "28944:45:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_tuple$__$",
+                      "typeString": "tuple()"
+                    }
+                  },
+                  "id": 1137,
+                  "nodeType": "ExpressionStatement",
+                  "src": "28944:45:1"
+                }
+              ]
+            },
+            "documentation": "@dev Internal function to burn a specific token.\nReverts if the token does not exist.\nDeprecated, use _burn(uint256) instead.\n@param owner owner of the token to burn\n@param tokenId uint256 ID of the token being burned",
+            "id": 1139,
+            "implemented": true,
+            "kind": "function",
+            "modifiers": [],
+            "name": "_burn",
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+              "parameters": [
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+                  "constant": false,
+                  "id": 1111,
+                  "name": "owner",
+                  "nodeType": "VariableDeclaration",
+                  "scope": 1139,
+                  "src": "28647:13:1",
+                  "stateVariable": false,
+                  "storageLocation": "default",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_address",
+                    "typeString": "address"
+                  },
+                  "typeName": {
+                    "id": 1110,
+                    "name": "address",
+                    "nodeType": "ElementaryTypeName",
+                    "src": "28647:7:1",
+                    "stateMutability": "nonpayable",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_address",
+                      "typeString": "address"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                },
+                {
+                  "constant": false,
+                  "id": 1113,
+                  "name": "tokenId",
+                  "nodeType": "VariableDeclaration",
+                  "scope": 1139,
+                  "src": "28662:15:1",
+                  "stateVariable": false,
+                  "storageLocation": "default",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_uint256",
+                    "typeString": "uint256"
+                  },
+                  "typeName": {
+                    "id": 1112,
+                    "name": "uint256",
+                    "nodeType": "ElementaryTypeName",
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+                            "typeDescriptions": {
+                              "typeIdentifier": "t_mapping$_t_address_$_t_array$_t_uint256_$dyn_storage_$",
+                              "typeString": "mapping(address => uint256[] storage ref)"
+                            }
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+                            "referencedDeclaration": 1197,
+                            "src": "31073:4:1",
+                            "typeDescriptions": {
+                              "typeIdentifier": "t_address",
+                              "typeString": "address"
+                            }
+                          },
+                          "isConstant": false,
+                          "isLValue": true,
+                          "isPure": false,
+                          "lValueRequested": false,
+                          "nodeType": "IndexAccess",
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+                            "typeIdentifier": "t_array$_t_uint256_$dyn_storage",
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+                          }
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+                        "memberName": "length",
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+                        "src": "31060:25:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      },
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+                      "memberName": "sub",
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+                      "src": "31060:29:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_function_internal_pure$_t_uint256_$_t_uint256_$returns$_t_uint256_$bound_to$_t_uint256_$",
+                        "typeString": "function (uint256,uint256) pure returns (uint256)"
+                      }
+                    },
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+                    "isConstant": false,
+                    "isLValue": false,
+                    "isPure": false,
+                    "kind": "functionCall",
+                    "lValueRequested": false,
+                    "names": [],
+                    "nodeType": "FunctionCall",
+                    "src": "31060:32:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_uint256",
+                      "typeString": "uint256"
+                    }
+                  },
+                  "nodeType": "VariableDeclarationStatement",
+                  "src": "31035:57:1"
+                },
+                {
+                  "assignments": [
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+                  ],
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+                      "stateVariable": false,
+                      "storageLocation": "default",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_uint256",
+                        "typeString": "uint256"
+                      },
+                      "typeName": {
+                        "id": 1212,
+                        "name": "uint256",
+                        "nodeType": "ElementaryTypeName",
+                        "src": "31102:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      },
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+                    }
+                  ],
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+                      "src": "31123:17:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_mapping$_t_uint256_$_t_uint256_$",
+                        "typeString": "mapping(uint256 => uint256)"
+                      }
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+                        "typeIdentifier": "t_uint256",
+                        "typeString": "uint256"
+                      }
+                    },
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+                    "nodeType": "IndexAccess",
+                    "src": "31123:26:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_uint256",
+                      "typeString": "uint256"
+                    }
+                  },
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+                },
+                {
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+                    },
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+                      "src": "31253:10:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_uint256",
+                        "typeString": "uint256"
+                      }
+                    },
+                    "nodeType": "BinaryOperation",
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+                      "name": "lastTokenIndex",
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+                      "referencedDeclaration": 1203,
+                      "src": "31267:14:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_uint256",
+                        "typeString": "uint256"
+                      }
+                    },
+                    "src": "31253:28:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_bool",
+                      "typeString": "bool"
+                    }
+                  },
+                  "falseBody": null,
+                  "id": 1244,
+                  "nodeType": "IfStatement",
+                  "src": "31249:323:1",
+                  "trueBody": {
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+                    "nodeType": "Block",
+                    "src": "31283:289:1",
+                    "statements": [
+                      {
+                        "assignments": [
+                          1222
+                        ],
+                        "declarations": [
+                          {
+                            "constant": false,
+                            "id": 1222,
+                            "name": "lastTokenId",
+                            "nodeType": "VariableDeclaration",
+                            "scope": 1243,
+                            "src": "31297:19:1",
+                            "stateVariable": false,
+                            "storageLocation": "default",
+                            "typeDescriptions": {
+                              "typeIdentifier": "t_uint256",
+                              "typeString": "uint256"
+                            },
+                            "typeName": {
+                              "id": 1221,
+                              "name": "uint256",
+                              "nodeType": "ElementaryTypeName",
+                              "src": "31297:7:1",
+                              "typeDescriptions": {
+                                "typeIdentifier": "t_uint256",
+                                "typeString": "uint256"
+                              }
+                            },
+                            "value": null,
+                            "visibility": "internal"
+                          }
+                        ],
+                        "id": 1228,
+                        "initialValue": {
+                          "argumentTypes": null,
+                          "baseExpression": {
+                            "argumentTypes": null,
+                            "baseExpression": {
+                              "argumentTypes": null,
+                              "id": 1223,
+                              "name": "_ownedTokens",
+                              "nodeType": "Identifier",
+                              "overloadedDeclarations": [],
+                              "referencedDeclaration": 981,
+                              "src": "31319:12:1",
+                              "typeDescriptions": {
+                                "typeIdentifier": "t_mapping$_t_address_$_t_array$_t_uint256_$dyn_storage_$",
+                                "typeString": "mapping(address => uint256[] storage ref)"
+                              }
+                            },
+                            "id": 1225,
+                            "indexExpression": {
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+                              "id": 1224,
+                              "name": "from",
+                              "nodeType": "Identifier",
+                              "overloadedDeclarations": [],
+                              "referencedDeclaration": 1197,
+                              "src": "31332:4:1",
+                              "typeDescriptions": {
+                                "typeIdentifier": "t_address",
+                                "typeString": "address"
+                              }
+                            },
+                            "isConstant": false,
+                            "isLValue": true,
+                            "isPure": false,
+                            "lValueRequested": false,
+                            "nodeType": "IndexAccess",
+                            "src": "31319:18:1",
+                            "typeDescriptions": {
+                              "typeIdentifier": "t_array$_t_uint256_$dyn_storage",
+                              "typeString": "uint256[] storage ref"
+                            }
+                          },
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+                            "argumentTypes": null,
+                            "id": 1226,
+                            "name": "lastTokenIndex",
+                            "nodeType": "Identifier",
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+                            "referencedDeclaration": 1203,
+                            "src": "31338:14:1",
+                            "typeDescriptions": {
+                              "typeIdentifier": "t_uint256",
+                              "typeString": "uint256"
+                            }
+                          },
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+                          "isPure": false,
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+                          "nodeType": "IndexAccess",
+                          "src": "31319:34:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_uint256",
+                            "typeString": "uint256"
+                          }
+                        },
+                        "nodeType": "VariableDeclarationStatement",
+                        "src": "31297:56:1"
+                      },
+                      {
+                        "expression": {
+                          "argumentTypes": null,
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+                          "isConstant": false,
+                          "isLValue": false,
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+                          "lValueRequested": false,
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+                            "baseExpression": {
+                              "argumentTypes": null,
+                              "baseExpression": {
+                                "argumentTypes": null,
+                                "id": 1229,
+                                "name": "_ownedTokens",
+                                "nodeType": "Identifier",
+                                "overloadedDeclarations": [],
+                                "referencedDeclaration": 981,
+                                "src": "31368:12:1",
+                                "typeDescriptions": {
+                                  "typeIdentifier": "t_mapping$_t_address_$_t_array$_t_uint256_$dyn_storage_$",
+                                  "typeString": "mapping(address => uint256[] storage ref)"
+                                }
+                              },
+                              "id": 1232,
+                              "indexExpression": {
+                                "argumentTypes": null,
+                                "id": 1230,
+                                "name": "from",
+                                "nodeType": "Identifier",
+                                "overloadedDeclarations": [],
+                                "referencedDeclaration": 1197,
+                                "src": "31381:4:1",
+                                "typeDescriptions": {
+                                  "typeIdentifier": "t_address",
+                                  "typeString": "address"
+                                }
+                              },
+                              "isConstant": false,
+                              "isLValue": true,
+                              "isPure": false,
+                              "lValueRequested": false,
+                              "nodeType": "IndexAccess",
+                              "src": "31368:18:1",
+                              "typeDescriptions": {
+                                "typeIdentifier": "t_array$_t_uint256_$dyn_storage",
+                                "typeString": "uint256[] storage ref"
+                              }
+                            },
+                            "id": 1233,
+                            "indexExpression": {
+                              "argumentTypes": null,
+                              "id": 1231,
+                              "name": "tokenIndex",
+                              "nodeType": "Identifier",
+                              "overloadedDeclarations": [],
+                              "referencedDeclaration": 1213,
+                              "src": "31387:10:1",
+                              "typeDescriptions": {
+                                "typeIdentifier": "t_uint256",
+                                "typeString": "uint256"
+                              }
+                            },
+                            "isConstant": false,
+                            "isLValue": true,
+                            "isPure": false,
+                            "lValueRequested": true,
+                            "nodeType": "IndexAccess",
+                            "src": "31368:30:1",
+                            "typeDescriptions": {
+                              "typeIdentifier": "t_uint256",
+                              "typeString": "uint256"
+                            }
+                          },
+                          "nodeType": "Assignment",
+                          "operator": "=",
+                          "rightHandSide": {
+                            "argumentTypes": null,
+                            "id": 1234,
+                            "name": "lastTokenId",
+                            "nodeType": "Identifier",
+                            "overloadedDeclarations": [],
+                            "referencedDeclaration": 1222,
+                            "src": "31401:11:1",
+                            "typeDescriptions": {
+                              "typeIdentifier": "t_uint256",
+                              "typeString": "uint256"
+                            }
+                          },
+                          "src": "31368:44:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_uint256",
+                            "typeString": "uint256"
+                          }
+                        },
+                        "id": 1236,
+                        "nodeType": "ExpressionStatement",
+                        "src": "31368:44:1"
+                      },
+                      {
+                        "expression": {
+                          "argumentTypes": null,
+                          "id": 1241,
+                          "isConstant": false,
+                          "isLValue": false,
+                          "isPure": false,
+                          "lValueRequested": false,
+                          "leftHandSide": {
+                            "argumentTypes": null,
+                            "baseExpression": {
+                              "argumentTypes": null,
+                              "id": 1237,
+                              "name": "_ownedTokensIndex",
+                              "nodeType": "Identifier",
+                              "overloadedDeclarations": [],
+                              "referencedDeclaration": 985,
+                              "src": "31484:17:1",
+                              "typeDescriptions": {
+                                "typeIdentifier": "t_mapping$_t_uint256_$_t_uint256_$",
+                                "typeString": "mapping(uint256 => uint256)"
+                              }
+                            },
+                            "id": 1239,
+                            "indexExpression": {
+                              "argumentTypes": null,
+                              "id": 1238,
+                              "name": "lastTokenId",
+                              "nodeType": "Identifier",
+                              "overloadedDeclarations": [],
+                              "referencedDeclaration": 1222,
+                              "src": "31502:11:1",
+                              "typeDescriptions": {
+                                "typeIdentifier": "t_uint256",
+                                "typeString": "uint256"
+                              }
+                            },
+                            "isConstant": false,
+                            "isLValue": true,
+                            "isPure": false,
+                            "lValueRequested": true,
+                            "nodeType": "IndexAccess",
+                            "src": "31484:30:1",
+                            "typeDescriptions": {
+                              "typeIdentifier": "t_uint256",
+                              "typeString": "uint256"
+                            }
+                          },
+                          "nodeType": "Assignment",
+                          "operator": "=",
+                          "rightHandSide": {
+                            "argumentTypes": null,
+                            "id": 1240,
+                            "name": "tokenIndex",
+                            "nodeType": "Identifier",
+                            "overloadedDeclarations": [],
+                            "referencedDeclaration": 1213,
+                            "src": "31517:10:1",
+                            "typeDescriptions": {
+                              "typeIdentifier": "t_uint256",
+                              "typeString": "uint256"
+                            }
+                          },
+                          "src": "31484:43:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_uint256",
+                            "typeString": "uint256"
+                          }
+                        },
+                        "id": 1242,
+                        "nodeType": "ExpressionStatement",
+                        "src": "31484:43:1"
+                      }
+                    ]
+                  }
+                },
+                {
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+                    "id": 1249,
+                    "isConstant": false,
+                    "isLValue": false,
+                    "isPure": false,
+                    "lValueRequested": false,
+                    "nodeType": "UnaryOperation",
+                    "operator": "--",
+                    "prefix": false,
+                    "src": "31658:27:1",
+                    "subExpression": {
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+                      "expression": {
+                        "argumentTypes": null,
+                        "baseExpression": {
+                          "argumentTypes": null,
+                          "id": 1245,
+                          "name": "_ownedTokens",
+                          "nodeType": "Identifier",
+                          "overloadedDeclarations": [],
+                          "referencedDeclaration": 981,
+                          "src": "31658:12:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_mapping$_t_address_$_t_array$_t_uint256_$dyn_storage_$",
+                            "typeString": "mapping(address => uint256[] storage ref)"
+                          }
+                        },
+                        "id": 1247,
+                        "indexExpression": {
+                          "argumentTypes": null,
+                          "id": 1246,
+                          "name": "from",
+                          "nodeType": "Identifier",
+                          "overloadedDeclarations": [],
+                          "referencedDeclaration": 1197,
+                          "src": "31671:4:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_address",
+                            "typeString": "address"
+                          }
+                        },
+                        "isConstant": false,
+                        "isLValue": true,
+                        "isPure": false,
+                        "lValueRequested": false,
+                        "nodeType": "IndexAccess",
+                        "src": "31658:18:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_array$_t_uint256_$dyn_storage",
+                          "typeString": "uint256[] storage ref"
+                        }
+                      },
+                      "id": 1248,
+                      "isConstant": false,
+                      "isLValue": true,
+                      "isPure": false,
+                      "lValueRequested": true,
+                      "memberName": "length",
+                      "nodeType": "MemberAccess",
+                      "referencedDeclaration": null,
+                      "src": "31658:25:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_uint256",
+                        "typeString": "uint256"
+                      }
+                    },
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_uint256",
+                      "typeString": "uint256"
+                    }
+                  },
+                  "id": 1250,
+                  "nodeType": "ExpressionStatement",
+                  "src": "31658:27:1"
+                }
+              ]
+            },
+            "documentation": "@dev Private function to remove a token from this extension's ownership-tracking data structures. Note that\nwhile the token is not assigned a new owner, the _ownedTokensIndex mapping is _not_ updated: this allows for\ngas optimizations e.g. when performing a transfer operation (avoiding double writes).\nThis has O(1) time complexity, but alters the order of the _ownedTokens array.\n@param from address representing the previous owner of the given token ID\n@param tokenId uint256 ID of the token to be removed from the tokens list of the given address",
+            "id": 1252,
+            "implemented": true,
+            "kind": "function",
+            "modifiers": [],
+            "name": "_removeTokenFromOwnerEnumeration",
+            "nodeType": "FunctionDefinition",
+            "parameters": {
+              "id": 1200,
+              "nodeType": "ParameterList",
+              "parameters": [
+                {
+                  "constant": false,
+                  "id": 1197,
+                  "name": "from",
+                  "nodeType": "VariableDeclaration",
+                  "scope": 1252,
+                  "src": "30815:12:1",
+                  "stateVariable": false,
+                  "storageLocation": "default",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_address",
+                    "typeString": "address"
+                  },
+                  "typeName": {
+                    "id": 1196,
+                    "name": "address",
+                    "nodeType": "ElementaryTypeName",
+                    "src": "30815:7:1",
+                    "stateMutability": "nonpayable",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_address",
+                      "typeString": "address"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                },
+                {
+                  "constant": false,
+                  "id": 1199,
+                  "name": "tokenId",
+                  "nodeType": "VariableDeclaration",
+                  "scope": 1252,
+                  "src": "30829:15:1",
+                  "stateVariable": false,
+                  "storageLocation": "default",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_uint256",
+                    "typeString": "uint256"
+                  },
+                  "typeName": {
+                    "id": 1198,
+                    "name": "uint256",
+                    "nodeType": "ElementaryTypeName",
+                    "src": "30829:7:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_uint256",
+                      "typeString": "uint256"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                }
+              ],
+              "src": "30814:31:1"
+            },
+            "returnParameters": {
+              "id": 1201,
+              "nodeType": "ParameterList",
+              "parameters": [],
+              "src": "30854:0:1"
+            },
+            "scope": 1302,
+            "src": "30773:1128:1",
+            "stateMutability": "nonpayable",
+            "superFunction": null,
+            "visibility": "private"
+          },
+          {
+            "body": {
+              "id": 1300,
+              "nodeType": "Block",
+              "src": "32260:993:1",
+              "statements": [
+                {
+                  "assignments": [
+                    1258
+                  ],
+                  "declarations": [
+                    {
+                      "constant": false,
+                      "id": 1258,
+                      "name": "lastTokenIndex",
+                      "nodeType": "VariableDeclaration",
+                      "scope": 1300,
+                      "src": "32438:22:1",
+                      "stateVariable": false,
+                      "storageLocation": "default",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_uint256",
+                        "typeString": "uint256"
+                      },
+                      "typeName": {
+                        "id": 1257,
+                        "name": "uint256",
+                        "nodeType": "ElementaryTypeName",
+                        "src": "32438:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      },
+                      "value": null,
+                      "visibility": "internal"
+                    }
+                  ],
+                  "id": 1264,
+                  "initialValue": {
+                    "argumentTypes": null,
+                    "arguments": [
+                      {
+                        "argumentTypes": null,
+                        "hexValue": "31",
+                        "id": 1262,
+                        "isConstant": false,
+                        "isLValue": false,
+                        "isPure": true,
+                        "kind": "number",
+                        "lValueRequested": false,
+                        "nodeType": "Literal",
+                        "src": "32485:1:1",
+                        "subdenomination": null,
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_rational_1_by_1",
+                          "typeString": "int_const 1"
+                        },
+                        "value": "1"
+                      }
+                    ],
+                    "expression": {
+                      "argumentTypes": [
+                        {
+                          "typeIdentifier": "t_rational_1_by_1",
+                          "typeString": "int_const 1"
+                        }
+                      ],
+                      "expression": {
+                        "argumentTypes": null,
+                        "expression": {
+                          "argumentTypes": null,
+                          "id": 1259,
+                          "name": "_allTokens",
+                          "nodeType": "Identifier",
+                          "overloadedDeclarations": [],
+                          "referencedDeclaration": 988,
+                          "src": "32463:10:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_array$_t_uint256_$dyn_storage",
+                            "typeString": "uint256[] storage ref"
+                          }
+                        },
+                        "id": 1260,
+                        "isConstant": false,
+                        "isLValue": true,
+                        "isPure": false,
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+                        "src": "36290:5:1",
+                        "typeDescriptions": {
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+                          "typeString": "address"
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+                        "name": "tokenId",
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+                        "src": "36297:7:1",
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+                        "src": "36278:5:1",
+                        "typeDescriptions": {
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+                          "typeString": "contract super ERC721Metadata"
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+                      "src": "36278:11:1",
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+                              "src": "36361:10:1",
+                              "typeDescriptions": {
+                                "typeIdentifier": "t_mapping$_t_uint256_$_t_string_storage_$",
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+                              "src": "36372:7:1",
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+                        "kind": "typeConversion",
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+                          "isLValue": false,
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+                          "nodeType": "UnaryOperation",
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+                          "src": "36409:26:1",
+                          "subExpression": {
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+                            "baseExpression": {
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+                              "nodeType": "Identifier",
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+                              "referencedDeclaration": 1338,
+                              "src": "36416:10:1",
+                              "typeDescriptions": {
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+                              "src": "36427:7:1",
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+                            "isLValue": true,
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+                            "typeString": "tuple()"
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+                    "name": "address",
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+                  "visibility": "internal"
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+                  "storageLocation": "default",
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+                      "typeString": "uint256"
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+            "src": "36212:240:1",
+            "stateMutability": "nonpayable",
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+        "src": "33817:2637:1"
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+        "literals": [
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+          "^",
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+          ".0"
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+        "nodeType": "PragmaDirective",
+        "src": "36518:23:1"
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+            "baseName": {
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+              "id": 1450,
+              "name": "ERC721",
+              "nodeType": "UserDefinedTypeName",
+              "referencedDeclaration": 944,
+              "src": "36838:6:1",
+              "typeDescriptions": {
+                "typeIdentifier": "t_contract$_ERC721_$944",
+                "typeString": "contract ERC721"
+              }
+            },
+            "id": 1451,
+            "nodeType": "InheritanceSpecifier",
+            "src": "36838:6:1"
+          },
+          {
+            "arguments": null,
+            "baseName": {
+              "contractScope": null,
+              "id": 1452,
+              "name": "ERC721Enumerable",
+              "nodeType": "UserDefinedTypeName",
+              "referencedDeclaration": 1302,
+              "src": "36846:16:1",
+              "typeDescriptions": {
+                "typeIdentifier": "t_contract$_ERC721Enumerable_$1302",
+                "typeString": "contract ERC721Enumerable"
+              }
+            },
+            "id": 1453,
+            "nodeType": "InheritanceSpecifier",
+            "src": "36846:16:1"
+          },
+          {
+            "arguments": null,
+            "baseName": {
+              "contractScope": null,
+              "id": 1454,
+              "name": "ERC721Metadata",
+              "nodeType": "UserDefinedTypeName",
+              "referencedDeclaration": 1448,
+              "src": "36864:14:1",
+              "typeDescriptions": {
+                "typeIdentifier": "t_contract$_ERC721Metadata_$1448",
+                "typeString": "contract ERC721Metadata"
+              }
+            },
+            "id": 1455,
+            "nodeType": "InheritanceSpecifier",
+            "src": "36864:14:1"
+          }
+        ],
+        "contractDependencies": [
+          944,
+          969,
+          23,
+          124,
+          386,
+          1302,
+          1323,
+          1448
+        ],
+        "contractKind": "contract",
+        "documentation": "@title Full ERC721 Token\nThis implementation includes all the required and some optional functionality of the ERC721 standard\nMoreover, it includes approve all functionality using operator terminology\n@dev see https://eips.ethereum.org/EIPS/eip-721",
+        "fullyImplemented": true,
+        "id": 1468,
+        "linearizedBaseContracts": [
+          1468,
+          1448,
+          1323,
+          1302,
+          969,
+          944,
+          124,
+          386,
+          23
+        ],
+        "name": "ERC721Full",
+        "nodeType": "ContractDefinition",
+        "nodes": [
+          {
+            "body": {
+              "id": 1466,
+              "nodeType": "Block",
+              "src": "36976:64:1",
+              "statements": []
+            },
+            "documentation": null,
+            "id": 1467,
+            "implemented": true,
+            "kind": "constructor",
+            "modifiers": [
+              {
+                "arguments": [
+                  {
+                    "argumentTypes": null,
+                    "id": 1462,
+                    "name": "name",
+                    "nodeType": "Identifier",
+                    "overloadedDeclarations": [],
+                    "referencedDeclaration": 1457,
+                    "src": "36962:4:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_string_memory_ptr",
+                      "typeString": "string memory"
+                    }
+                  },
+                  {
+                    "argumentTypes": null,
+                    "id": 1463,
+                    "name": "symbol",
+                    "nodeType": "Identifier",
+                    "overloadedDeclarations": [],
+                    "referencedDeclaration": 1459,
+                    "src": "36968:6:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_string_memory_ptr",
+                      "typeString": "string memory"
+                    }
+                  }
+                ],
+                "id": 1464,
+                "modifierName": {
+                  "argumentTypes": null,
+                  "id": 1461,
+                  "name": "ERC721Metadata",
+                  "nodeType": "Identifier",
+                  "overloadedDeclarations": [],
+                  "referencedDeclaration": 1448,
+                  "src": "36947:14:1",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_type$_t_contract$_ERC721Metadata_$1448_$",
+                    "typeString": "type(contract ERC721Metadata)"
+                  }
+                },
+                "nodeType": "ModifierInvocation",
+                "src": "36947:28:1"
+              }
+            ],
+            "name": "",
+            "nodeType": "FunctionDefinition",
+            "parameters": {
+              "id": 1460,
+              "nodeType": "ParameterList",
+              "parameters": [
+                {
+                  "constant": false,
+                  "id": 1457,
+                  "name": "name",
+                  "nodeType": "VariableDeclaration",
+                  "scope": 1467,
+                  "src": "36898:18:1",
+                  "stateVariable": false,
+                  "storageLocation": "memory",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_string_memory_ptr",
+                    "typeString": "string"
+                  },
+                  "typeName": {
+                    "id": 1456,
+                    "name": "string",
+                    "nodeType": "ElementaryTypeName",
+                    "src": "36898:6:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_string_storage_ptr",
+                      "typeString": "string"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                },
+                {
+                  "constant": false,
+                  "id": 1459,
+                  "name": "symbol",
+                  "nodeType": "VariableDeclaration",
+                  "scope": 1467,
+                  "src": "36918:20:1",
+                  "stateVariable": false,
+                  "storageLocation": "memory",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_string_memory_ptr",
+                    "typeString": "string"
+                  },
+                  "typeName": {
+                    "id": 1458,
+                    "name": "string",
+                    "nodeType": "ElementaryTypeName",
+                    "src": "36918:6:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_string_storage_ptr",
+                      "typeString": "string"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                }
+              ],
+              "src": "36897:42:1"
+            },
+            "returnParameters": {
+              "id": 1465,
+              "nodeType": "ParameterList",
+              "parameters": [],
+              "src": "36976:0:1"
+            },
+            "scope": 1468,
+            "src": "36885:155:1",
+            "stateMutability": "nonpayable",
+            "superFunction": null,
+            "visibility": "public"
+          }
+        ],
+        "scope": 1469,
+        "src": "36815:227:1"
+      }
+    ],
+    "src": "61:36982:1"
+  },
+  "compiler": {
+    "name": "solc",
+    "version": "0.5.0+commit.1d4f565a.Emscripten.clang"
+  },
+  "networks": {},
+  "schemaVersion": "3.0.2",
+  "updatedAt": "2019-09-05T15:01:08.524Z",
+  "devdoc": {
+    "details": "Collection of functions related to the address type,",
+    "methods": {}
+  },
+  "userdoc": {
+    "methods": {}
+  }
+}
\ No newline at end of file
diff --git a/src/abis/Color.json b/src/abis/Color.json
new file mode 100644
index 0000000..3973cbf
--- /dev/null
+++ b/src/abis/Color.json
@@ -0,0 +1,1945 @@
+{
+  "contractName": "Color",
+  "abi": [
+    {
+      "constant": true,
+      "inputs": [
+        {
+          "name": "interfaceId",
+          "type": "bytes4"
+        }
+      ],
+      "name": "supportsInterface",
+      "outputs": [
+        {
+          "name": "",
+          "type": "bool"
+        }
+      ],
+      "payable": false,
+      "stateMutability": "view",
+      "type": "function",
+      "signature": "0x01ffc9a7"
+    },
+    {
+      "constant": true,
+      "inputs": [],
+      "name": "name",
+      "outputs": [
+        {
+          "name": "",
+          "type": "string"
+        }
+      ],
+      "payable": false,
+      "stateMutability": "view",
+      "type": "function",
+      "signature": "0x06fdde03"
+    },
+    {
+      "constant": true,
+      "inputs": [
+        {
+          "name": "tokenId",
+          "type": "uint256"
+        }
+      ],
+      "name": "getApproved",
+      "outputs": [
+        {
+          "name": "",
+          "type": "address"
+        }
+      ],
+      "payable": false,
+      "stateMutability": "view",
+      "type": "function",
+      "signature": "0x081812fc"
+    },
+    {
+      "constant": false,
+      "inputs": [
+        {
+          "name": "to",
+          "type": "address"
+        },
+        {
+          "name": "tokenId",
+          "type": "uint256"
+        }
+      ],
+      "name": "approve",
+      "outputs": [],
+      "payable": false,
+      "stateMutability": "nonpayable",
+      "type": "function",
+      "signature": "0x095ea7b3"
+    },
+    {
+      "constant": true,
+      "inputs": [],
+      "name": "totalSupply",
+      "outputs": [
+        {
+          "name": "",
+          "type": "uint256"
+        }
+      ],
+      "payable": false,
+      "stateMutability": "view",
+      "type": "function",
+      "signature": "0x18160ddd"
+    },
+    {
+      "constant": false,
+      "inputs": [
+        {
+          "name": "from",
+          "type": "address"
+        },
+        {
+          "name": "to",
+          "type": "address"
+        },
+        {
+          "name": "tokenId",
+          "type": "uint256"
+        }
+      ],
+      "name": "transferFrom",
+      "outputs": [],
+      "payable": false,
+      "stateMutability": "nonpayable",
+      "type": "function",
+      "signature": "0x23b872dd"
+    },
+    {
+      "constant": true,
+      "inputs": [
+        {
+          "name": "owner",
+          "type": "address"
+        },
+        {
+          "name": "index",
+          "type": "uint256"
+        }
+      ],
+      "name": "tokenOfOwnerByIndex",
+      "outputs": [
+        {
+          "name": "",
+          "type": "uint256"
+        }
+      ],
+      "payable": false,
+      "stateMutability": "view",
+      "type": "function",
+      "signature": "0x2f745c59"
+    },
+    {
+      "constant": false,
+      "inputs": [
+        {
+          "name": "from",
+          "type": "address"
+        },
+        {
+          "name": "to",
+          "type": "address"
+        },
+        {
+          "name": "tokenId",
+          "type": "uint256"
+        }
+      ],
+      "name": "safeTransferFrom",
+      "outputs": [],
+      "payable": false,
+      "stateMutability": "nonpayable",
+      "type": "function",
+      "signature": "0x42842e0e"
+    },
+    {
+      "constant": true,
+      "inputs": [
+        {
+          "name": "index",
+          "type": "uint256"
+        }
+      ],
+      "name": "tokenByIndex",
+      "outputs": [
+        {
+          "name": "",
+          "type": "uint256"
+        }
+      ],
+      "payable": false,
+      "stateMutability": "view",
+      "type": "function",
+      "signature": "0x4f6ccce7"
+    },
+    {
+      "constant": true,
+      "inputs": [
+        {
+          "name": "tokenId",
+          "type": "uint256"
+        }
+      ],
+      "name": "ownerOf",
+      "outputs": [
+        {
+          "name": "",
+          "type": "address"
+        }
+      ],
+      "payable": false,
+      "stateMutability": "view",
+      "type": "function",
+      "signature": "0x6352211e"
+    },
+    {
+      "constant": true,
+      "inputs": [
+        {
+          "name": "owner",
+          "type": "address"
+        }
+      ],
+      "name": "balanceOf",
+      "outputs": [
+        {
+          "name": "",
+          "type": "uint256"
+        }
+      ],
+      "payable": false,
+      "stateMutability": "view",
+      "type": "function",
+      "signature": "0x70a08231"
+    },
+    {
+      "constant": true,
+      "inputs": [],
+      "name": "symbol",
+      "outputs": [
+        {
+          "name": "",
+          "type": "string"
+        }
+      ],
+      "payable": false,
+      "stateMutability": "view",
+      "type": "function",
+      "signature": "0x95d89b41"
+    },
+    {
+      "constant": false,
+      "inputs": [
+        {
+          "name": "to",
+          "type": "address"
+        },
+        {
+          "name": "approved",
+          "type": "bool"
+        }
+      ],
+      "name": "setApprovalForAll",
+      "outputs": [],
+      "payable": false,
+      "stateMutability": "nonpayable",
+      "type": "function",
+      "signature": "0xa22cb465"
+    },
+    {
+      "constant": false,
+      "inputs": [
+        {
+          "name": "from",
+          "type": "address"
+        },
+        {
+          "name": "to",
+          "type": "address"
+        },
+        {
+          "name": "tokenId",
+          "type": "uint256"
+        },
+        {
+          "name": "_data",
+          "type": "bytes"
+        }
+      ],
+      "name": "safeTransferFrom",
+      "outputs": [],
+      "payable": false,
+      "stateMutability": "nonpayable",
+      "type": "function",
+      "signature": "0xb88d4fde"
+    },
+    {
+      "constant": true,
+      "inputs": [
+        {
+          "name": "",
+          "type": "uint256"
+        }
+      ],
+      "name": "colors",
+      "outputs": [
+        {
+          "name": "",
+          "type": "string"
+        }
+      ],
+      "payable": false,
+      "stateMutability": "view",
+      "type": "function",
+      "signature": "0xbd11f69d"
+    },
+    {
+      "constant": true,
+      "inputs": [
+        {
+          "name": "tokenId",
+          "type": "uint256"
+        }
+      ],
+      "name": "tokenURI",
+      "outputs": [
+        {
+          "name": "",
+          "type": "string"
+        }
+      ],
+      "payable": false,
+      "stateMutability": "view",
+      "type": "function",
+      "signature": "0xc87b56dd"
+    },
+    {
+      "constant": true,
+      "inputs": [
+        {
+          "name": "owner",
+          "type": "address"
+        },
+        {
+          "name": "operator",
+          "type": "address"
+        }
+      ],
+      "name": "isApprovedForAll",
+      "outputs": [
+        {
+          "name": "",
+          "type": "bool"
+        }
+      ],
+      "payable": false,
+      "stateMutability": "view",
+      "type": "function",
+      "signature": "0xe985e9c5"
+    },
+    {
+      "inputs": [],
+      "payable": false,
+      "stateMutability": "nonpayable",
+      "type": "constructor",
+      "signature": "constructor"
+    },
+    {
+      "anonymous": false,
+      "inputs": [
+        {
+          "indexed": true,
+          "name": "from",
+          "type": "address"
+        },
+        {
+          "indexed": true,
+          "name": "to",
+          "type": "address"
+        },
+        {
+          "indexed": true,
+          "name": "tokenId",
+          "type": "uint256"
+        }
+      ],
+      "name": "Transfer",
+      "type": "event",
+      "signature": "0xddf252ad1be2c89b69c2b068fc378daa952ba7f163c4a11628f55a4df523b3ef"
+    },
+    {
+      "anonymous": false,
+      "inputs": [
+        {
+          "indexed": true,
+          "name": "owner",
+          "type": "address"
+        },
+        {
+          "indexed": true,
+          "name": "approved",
+          "type": "address"
+        },
+        {
+          "indexed": true,
+          "name": "tokenId",
+          "type": "uint256"
+        }
+      ],
+      "name": "Approval",
+      "type": "event",
+      "signature": "0x8c5be1e5ebec7d5bd14f71427d1e84f3dd0314c0f7b2291e5b200ac8c7c3b925"
+    },
+    {
+      "anonymous": false,
+      "inputs": [
+        {
+          "indexed": true,
+          "name": "owner",
+          "type": "address"
+        },
+        {
+          "indexed": true,
+          "name": "operator",
+          "type": "address"
+        },
+        {
+          "indexed": false,
+          "name": "approved",
+          "type": "bool"
+        }
+      ],
+      "name": "ApprovalForAll",
+      "type": "event",
+      "signature": "0x17307eab39ab6107e8899845ad3d59bd9653f200f220920489ca2b5937696c31"
+    },
+    {
+      "constant": false,
+      "inputs": [
+        {
+          "name": "_color",
+          "type": "string"
+        }
+      ],
+      "name": "mint",
+      "outputs": [],
+      "payable": false,
+      "stateMutability": "nonpayable",
+      "type": "function",
+      "signature": "0xd85d3d27"
+    }
+  ],
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+  "source": "pragma solidity 0.5.0;\n\nimport \"./ERC721Full.sol\";\n\ncontract Color is ERC721Full {\n  string[] public colors;\n  mapping(string => bool) _colorExists;\n\n  constructor() ERC721Full(\"Color\", \"COLOR\") public {\n  }\n\n  // E.G. color = \"#FFFFFF\"\n  function mint(string memory _color) public {\n    require(!_colorExists[_color]);\n    uint _id = colors.push(_color);\n    _mint(msg.sender, _id);\n    _colorExists[_color] = true;\n  }\n\n}\n",
+  "sourcePath": "/Users/gregory/code/nft/src/contracts/Color.sol",
+  "ast": {
+    "absolutePath": "/Users/gregory/code/nft/src/contracts/Color.sol",
+    "exportedSymbols": {
+      "Color": [
+        52
+      ]
+    },
+    "id": 53,
+    "nodeType": "SourceUnit",
+    "nodes": [
+      {
+        "id": 1,
+        "literals": [
+          "solidity",
+          "0.5",
+          ".0"
+        ],
+        "nodeType": "PragmaDirective",
+        "src": "0:22:0"
+      },
+      {
+        "absolutePath": "/Users/gregory/code/nft/src/contracts/ERC721Full.sol",
+        "file": "./ERC721Full.sol",
+        "id": 2,
+        "nodeType": "ImportDirective",
+        "scope": 53,
+        "sourceUnit": 1508,
+        "src": "24:26:0",
+        "symbolAliases": [],
+        "unitAlias": ""
+      },
+      {
+        "baseContracts": [
+          {
+            "arguments": null,
+            "baseName": {
+              "contractScope": null,
+              "id": 3,
+              "name": "ERC721Full",
+              "nodeType": "UserDefinedTypeName",
+              "referencedDeclaration": 1507,
+              "src": "70:10:0",
+              "typeDescriptions": {
+                "typeIdentifier": "t_contract$_ERC721Full_$1507",
+                "typeString": "contract ERC721Full"
+              }
+            },
+            "id": 4,
+            "nodeType": "InheritanceSpecifier",
+            "src": "70:10:0"
+          }
+        ],
+        "contractDependencies": [
+          62,
+          163,
+          425,
+          983,
+          1008,
+          1341,
+          1362,
+          1487,
+          1507
+        ],
+        "contractKind": "contract",
+        "documentation": null,
+        "fullyImplemented": true,
+        "id": 52,
+        "linearizedBaseContracts": [
+          52,
+          1507,
+          1487,
+          1362,
+          1341,
+          1008,
+          983,
+          163,
+          425,
+          62
+        ],
+        "name": "Color",
+        "nodeType": "ContractDefinition",
+        "nodes": [
+          {
+            "constant": false,
+            "id": 7,
+            "name": "colors",
+            "nodeType": "VariableDeclaration",
+            "scope": 52,
+            "src": "85:22:0",
+            "stateVariable": true,
+            "storageLocation": "default",
+            "typeDescriptions": {
+              "typeIdentifier": "t_array$_t_string_storage_$dyn_storage",
+              "typeString": "string[]"
+            },
+            "typeName": {
+              "baseType": {
+                "id": 5,
+                "name": "string",
+                "nodeType": "ElementaryTypeName",
+                "src": "85:6:0",
+                "typeDescriptions": {
+                  "typeIdentifier": "t_string_storage_ptr",
+                  "typeString": "string"
+                }
+              },
+              "id": 6,
+              "length": null,
+              "nodeType": "ArrayTypeName",
+              "src": "85:8:0",
+              "typeDescriptions": {
+                "typeIdentifier": "t_array$_t_string_storage_$dyn_storage_ptr",
+                "typeString": "string[]"
+              }
+            },
+            "value": null,
+            "visibility": "public"
+          },
+          {
+            "constant": false,
+            "id": 11,
+            "name": "_colorExists",
+            "nodeType": "VariableDeclaration",
+            "scope": 52,
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+                    "typeString": "type(contract ERC721Full)"
+                  }
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+              }
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+            },
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+            "src": "152:55:0",
+            "stateMutability": "nonpayable",
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+            "visibility": "public"
+          },
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+              "nodeType": "Block",
+              "src": "282:138:0",
+              "statements": [
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+                    "arguments": [
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+                        "isConstant": false,
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+                        "nodeType": "UnaryOperation",
+                        "operator": "!",
+                        "prefix": true,
+                        "src": "296:21:0",
+                        "subExpression": {
+                          "argumentTypes": null,
+                          "baseExpression": {
+                            "argumentTypes": null,
+                            "id": 25,
+                            "name": "_colorExists",
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+                            "overloadedDeclarations": [],
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+                            "src": "297:12:0",
+                            "typeDescriptions": {
+                              "typeIdentifier": "t_mapping$_t_string_memory_$_t_bool_$",
+                              "typeString": "mapping(string memory => bool)"
+                            }
+                          },
+                          "id": 27,
+                          "indexExpression": {
+                            "argumentTypes": null,
+                            "id": 26,
+                            "name": "_color",
+                            "nodeType": "Identifier",
+                            "overloadedDeclarations": [],
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+                            "src": "310:6:0",
+                            "typeDescriptions": {
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+                          "isPure": false,
+                          "lValueRequested": false,
+                          "nodeType": "IndexAccess",
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+                            "typeIdentifier": "t_bool",
+                            "typeString": "bool"
+                          }
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+                        "typeDescriptions": {
+                          "typeIdentifier": "t_bool",
+                          "typeString": "bool"
+                        }
+                      }
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+                        1582,
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+                      "src": "288:7:0",
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+                      "src": "324:8:0",
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+                      "storageLocation": "default",
+                      "typeDescriptions": {
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+                        "src": "347:6:0",
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+                          "typeIdentifier": "t_string_memory_ptr",
+                          "typeString": "string memory"
+                        }
+                      }
+                    ],
+                    "expression": {
+                      "argumentTypes": [
+                        {
+                          "typeIdentifier": "t_string_memory_ptr",
+                          "typeString": "string memory"
+                        }
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+                        "id": 33,
+                        "name": "colors",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 7,
+                        "src": "335:6:0",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_array$_t_string_storage_$dyn_storage",
+                          "typeString": "string storage ref[] storage ref"
+                        }
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+                      "isConstant": false,
+                      "isLValue": false,
+                      "isPure": false,
+                      "lValueRequested": false,
+                      "memberName": "push",
+                      "nodeType": "MemberAccess",
+                      "referencedDeclaration": null,
+                      "src": "335:11:0",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_function_arraypush_nonpayable$_t_string_storage_$returns$_t_uint256_$",
+                        "typeString": "function (string storage ref) returns (uint256)"
+                      }
+                    },
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+                    "isConstant": false,
+                    "isLValue": false,
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+                    "kind": "functionCall",
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+                    "typeDescriptions": {
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+                      "typeString": "uint256"
+                    }
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+                    "arguments": [
+                      {
+                        "argumentTypes": null,
+                        "expression": {
+                          "argumentTypes": null,
+                          "id": 39,
+                          "name": "msg",
+                          "nodeType": "Identifier",
+                          "overloadedDeclarations": [],
+                          "referencedDeclaration": 1579,
+                          "src": "366:3:0",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_magic_message",
+                            "typeString": "msg"
+                          }
+                        },
+                        "id": 40,
+                        "isConstant": false,
+                        "isLValue": false,
+                        "isPure": false,
+                        "lValueRequested": false,
+                        "memberName": "sender",
+                        "nodeType": "MemberAccess",
+                        "referencedDeclaration": null,
+                        "src": "366:10:0",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_address_payable",
+                          "typeString": "address payable"
+                        }
+                      },
+                      {
+                        "argumentTypes": null,
+                        "id": 41,
+                        "name": "_id",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 32,
+                        "src": "378:3:0",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      }
+                    ],
+                    "expression": {
+                      "argumentTypes": [
+                        {
+                          "typeIdentifier": "t_address_payable",
+                          "typeString": "address payable"
+                        },
+                        {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      ],
+                      "id": 38,
+                      "name": "_mint",
+                      "nodeType": "Identifier",
+                      "overloadedDeclarations": [
+                        1148
+                      ],
+                      "referencedDeclaration": 1148,
+                      "src": "360:5:0",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_function_internal_nonpayable$_t_address_$_t_uint256_$returns$__$",
+                        "typeString": "function (address,uint256)"
+                      }
+                    },
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+                    "isConstant": false,
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+                    "src": "360:22:0",
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+                  "src": "360:22:0"
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+                      "baseExpression": {
+                        "argumentTypes": null,
+                        "id": 44,
+                        "name": "_colorExists",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 11,
+                        "src": "388:12:0",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_mapping$_t_string_memory_$_t_bool_$",
+                          "typeString": "mapping(string memory => bool)"
+                        }
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+                      "indexExpression": {
+                        "argumentTypes": null,
+                        "id": 45,
+                        "name": "_color",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 21,
+                        "src": "401:6:0",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_string_memory_ptr",
+                          "typeString": "string memory"
+                        }
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+                      "isPure": false,
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+                      "nodeType": "IndexAccess",
+                      "src": "388:20:0",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_bool",
+                        "typeString": "bool"
+                      }
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+                    "nodeType": "Assignment",
+                    "operator": "=",
+                    "rightHandSide": {
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+                      "hexValue": "74727565",
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+                      "isConstant": false,
+                      "isLValue": false,
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+                      "kind": "bool",
+                      "lValueRequested": false,
+                      "nodeType": "Literal",
+                      "src": "411:4:0",
+                      "subdenomination": null,
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_bool",
+                        "typeString": "bool"
+                      },
+                      "value": "true"
+                    },
+                    "src": "388:27:0",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_bool",
+                      "typeString": "bool"
+                    }
+                  },
+                  "id": 49,
+                  "nodeType": "ExpressionStatement",
+                  "src": "388:27:0"
+                }
+              ]
+            },
+            "documentation": null,
+            "id": 51,
+            "implemented": true,
+            "kind": "function",
+            "modifiers": [],
+            "name": "mint",
+            "nodeType": "FunctionDefinition",
+            "parameters": {
+              "id": 22,
+              "nodeType": "ParameterList",
+              "parameters": [
+                {
+                  "constant": false,
+                  "id": 21,
+                  "name": "_color",
+                  "nodeType": "VariableDeclaration",
+                  "scope": 51,
+                  "src": "253:20:0",
+                  "stateVariable": false,
+                  "storageLocation": "memory",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_string_memory_ptr",
+                    "typeString": "string"
+                  },
+                  "typeName": {
+                    "id": 20,
+                    "name": "string",
+                    "nodeType": "ElementaryTypeName",
+                    "src": "253:6:0",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_string_storage_ptr",
+                      "typeString": "string"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                }
+              ],
+              "src": "252:22:0"
+            },
+            "returnParameters": {
+              "id": 23,
+              "nodeType": "ParameterList",
+              "parameters": [],
+              "src": "282:0:0"
+            },
+            "scope": 52,
+            "src": "239:181:0",
+            "stateMutability": "nonpayable",
+            "superFunction": null,
+            "visibility": "public"
+          }
+        ],
+        "scope": 53,
+        "src": "52:371:0"
+      }
+    ],
+    "src": "0:424:0"
+  },
+  "compiler": {
+    "name": "solc",
+    "version": "0.5.0+commit.1d4f565a.Emscripten.clang"
+  },
+  "networks": {
+    "5777": {
+      "events": {},
+      "links": {},
+      "address": "0x7629eba1fBb260E6Da2BDE3a9e485A137126a700",
+      "transactionHash": "0xb47a33e6f4784164114f2936503f8fcd395dbd3a3919115f9ea993a70d256918"
+    }
+  },
+  "schemaVersion": "3.0.2",
+  "updatedAt": "2019-09-05T15:46:34.743Z",
+  "devdoc": {
+    "methods": {
+      "approve(address,uint256)": {
+        "details": "Approves another address to transfer the given token ID The zero address indicates there is no approved address. There can only be one approved address per token at a given time. Can only be called by the token owner or an approved operator.",
+        "params": {
+          "to": "address to be approved for the given token ID",
+          "tokenId": "uint256 ID of the token to be approved"
+        }
+      },
+      "balanceOf(address)": {
+        "details": "Gets the balance of the specified address.",
+        "params": {
+          "owner": "address to query the balance of"
+        },
+        "return": "uint256 representing the amount owned by the passed address"
+      },
+      "getApproved(uint256)": {
+        "details": "Gets the approved address for a token ID, or zero if no address set Reverts if the token ID does not exist.",
+        "params": {
+          "tokenId": "uint256 ID of the token to query the approval of"
+        },
+        "return": "address currently approved for the given token ID"
+      },
+      "isApprovedForAll(address,address)": {
+        "details": "Tells whether an operator is approved by a given owner.",
+        "params": {
+          "operator": "operator address which you want to query the approval of",
+          "owner": "owner address which you want to query the approval of"
+        },
+        "return": "bool whether the given operator is approved by the given owner"
+      },
+      "name()": {
+        "details": "Gets the token name.",
+        "return": "string representing the token name"
+      },
+      "ownerOf(uint256)": {
+        "details": "Gets the owner of the specified token ID.",
+        "params": {
+          "tokenId": "uint256 ID of the token to query the owner of"
+        },
+        "return": "address currently marked as the owner of the given token ID"
+      },
+      "safeTransferFrom(address,address,uint256)": {
+        "details": "Safely transfers the ownership of a given token ID to another address If the target address is a contract, it must implement `onERC721Received`, which is called upon a safe transfer, and return the magic value `bytes4(keccak256(\"onERC721Received(address,address,uint256,bytes)\"))`; otherwise, the transfer is reverted. Requires the msg.sender to be the owner, approved, or operator",
+        "params": {
+          "from": "current owner of the token",
+          "to": "address to receive the ownership of the given token ID",
+          "tokenId": "uint256 ID of the token to be transferred"
+        }
+      },
+      "safeTransferFrom(address,address,uint256,bytes)": {
+        "details": "Safely transfers the ownership of a given token ID to another address If the target address is a contract, it must implement `onERC721Received`, which is called upon a safe transfer, and return the magic value `bytes4(keccak256(\"onERC721Received(address,address,uint256,bytes)\"))`; otherwise, the transfer is reverted. Requires the msg.sender to be the owner, approved, or operator",
+        "params": {
+          "_data": "bytes data to send along with a safe transfer check",
+          "from": "current owner of the token",
+          "to": "address to receive the ownership of the given token ID",
+          "tokenId": "uint256 ID of the token to be transferred"
+        }
+      },
+      "setApprovalForAll(address,bool)": {
+        "details": "Sets or unsets the approval of a given operator An operator is allowed to transfer all tokens of the sender on their behalf.",
+        "params": {
+          "approved": "representing the status of the approval to be set",
+          "to": "operator address to set the approval"
+        }
+      },
+      "supportsInterface(bytes4)": {
+        "details": "See `IERC165.supportsInterface`.     * Time complexity O(1), guaranteed to always use less than 30 000 gas."
+      },
+      "symbol()": {
+        "details": "Gets the token symbol.",
+        "return": "string representing the token symbol"
+      },
+      "tokenByIndex(uint256)": {
+        "details": "Gets the token ID at a given index of all the tokens in this contract Reverts if the index is greater or equal to the total number of tokens.",
+        "params": {
+          "index": "uint256 representing the index to be accessed of the tokens list"
+        },
+        "return": "uint256 token ID at the given index of the tokens list"
+      },
+      "tokenOfOwnerByIndex(address,uint256)": {
+        "details": "Gets the token ID at a given index of the tokens list of the requested owner.",
+        "params": {
+          "index": "uint256 representing the index to be accessed of the requested tokens list",
+          "owner": "address owning the tokens list to be accessed"
+        },
+        "return": "uint256 token ID at the given index of the tokens list owned by the requested address"
+      },
+      "tokenURI(uint256)": {
+        "details": "Returns an URI for a given token ID. Throws if the token ID does not exist. May return an empty string.",
+        "params": {
+          "tokenId": "uint256 ID of the token to query"
+        }
+      },
+      "totalSupply()": {
+        "details": "Gets the total amount of tokens stored by the contract.",
+        "return": "uint256 representing the total amount of tokens"
+      },
+      "transferFrom(address,address,uint256)": {
+        "details": "Transfers the ownership of a given token ID to another address. Usage of this method is discouraged, use `safeTransferFrom` whenever possible. Requires the msg.sender to be the owner, approved, or operator.",
+        "params": {
+          "from": "current owner of the token",
+          "to": "address to receive the ownership of the given token ID",
+          "tokenId": "uint256 ID of the token to be transferred"
+        }
+      }
+    }
+  },
+  "userdoc": {
+    "methods": {}
+  }
+}
\ No newline at end of file
diff --git a/src/abis/Counters.json b/src/abis/Counters.json
new file mode 100644
index 0000000..8dc6f02
--- /dev/null
+++ b/src/abis/Counters.json
@@ -0,0 +1,37450 @@
+{
+  "contractName": "Counters",
+  "abi": [],
+  "bytecode": "0x604c602c600b82828239805160001a60731460008114601c57601e565bfe5b5030600052607381538281f3fe73000000000000000000000000000000000000000030146080604052600080fdfea165627a7a72305820f19ec424b82475ebe631f2854b885dcc95da62364ec8658a04f38c5c0641a8ab0029",
+  "deployedBytecode": "0x73000000000000000000000000000000000000000030146080604052600080fdfea165627a7a72305820f19ec424b82475ebe631f2854b885dcc95da62364ec8658a04f38c5c0641a8ab0029",
+  "sourceMap": "9303:759:1:-;;132:2:-1;166:7;155:9;146:7;137:37;252:7;246:14;243:1;238:23;232:4;229:33;270:1;265:20;;;;222:63;;265:20;274:9;222:63;;298:9;295:1;288:20;328:4;319:7;311:22;352:7;343;336:24",
+  "deployedSourceMap": "9303:759:1:-;;;;;;;;",
+  "source": "\n// File: @openzeppelin/contracts/introspection/IERC165.sol\n\npragma solidity ^0.5.0;\n\n/**\n * @dev Interface of the ERC165 standard, as defined in the\n * [EIP](https://eips.ethereum.org/EIPS/eip-165).\n *\n * Implementers can declare support of contract interfaces, which can then be\n * queried by others (`ERC165Checker`).\n *\n * For an implementation, see `ERC165`.\n */\ninterface IERC165 {\n    /**\n     * @dev Returns true if this contract implements the interface defined by\n     * `interfaceId`. See the corresponding\n     * [EIP section](https://eips.ethereum.org/EIPS/eip-165#how-interfaces-are-identified)\n     * to learn more about how these ids are created.\n     *\n     * This function call must use less than 30 000 gas.\n     */\n    function supportsInterface(bytes4 interfaceId) external view returns (bool);\n}\n\n// File: @openzeppelin/contracts/token/ERC721/IERC721.sol\n\npragma solidity ^0.5.0;\n\n\n/**\n * @dev Required interface of an ERC721 compliant contract.\n */\ncontract IERC721 is IERC165 {\n    event Transfer(address indexed from, address indexed to, uint256 indexed tokenId);\n    event Approval(address indexed owner, address indexed approved, uint256 indexed tokenId);\n    event ApprovalForAll(address indexed owner, address indexed operator, bool approved);\n\n    /**\n     * @dev Returns the number of NFTs in `owner`'s account.\n     */\n    function balanceOf(address owner) public view returns (uint256 balance);\n\n    /**\n     * @dev Returns the owner of the NFT specified by `tokenId`.\n     */\n    function ownerOf(uint256 tokenId) public view returns (address owner);\n\n    /**\n     * @dev Transfers a specific NFT (`tokenId`) from one account (`from`) to\n     * another (`to`).\n     *\n     * \n     *\n     * Requirements:\n     * - `from`, `to` cannot be zero.\n     * - `tokenId` must be owned by `from`.\n     * - If the caller is not `from`, it must be have been allowed to move this\n     * NFT by either `approve` or `setApproveForAll`.\n     */\n    function safeTransferFrom(address from, address to, uint256 tokenId) public;\n    /**\n     * @dev Transfers a specific NFT (`tokenId`) from one account (`from`) to\n     * another (`to`).\n     *\n     * Requirements:\n     * - If the caller is not `from`, it must be approved to move this NFT by\n     * either `approve` or `setApproveForAll`.\n     */\n    function transferFrom(address from, address to, uint256 tokenId) public;\n    function approve(address to, uint256 tokenId) public;\n    function getApproved(uint256 tokenId) public view returns (address operator);\n\n    function setApprovalForAll(address operator, bool _approved) public;\n    function isApprovedForAll(address owner, address operator) public view returns (bool);\n\n\n    function safeTransferFrom(address from, address to, uint256 tokenId, bytes memory data) public;\n}\n\n// File: @openzeppelin/contracts/token/ERC721/IERC721Receiver.sol\n\npragma solidity ^0.5.0;\n\n/**\n * @title ERC721 token receiver interface\n * @dev Interface for any contract that wants to support safeTransfers\n * from ERC721 asset contracts.\n */\ncontract IERC721Receiver {\n    /**\n     * @notice Handle the receipt of an NFT\n     * @dev The ERC721 smart contract calls this function on the recipient\n     * after a `safeTransfer`. This function MUST return the function selector,\n     * otherwise the caller will revert the transaction. The selector to be\n     * returned can be obtained as `this.onERC721Received.selector`. This\n     * function MAY throw to revert and reject the transfer.\n     * Note: the ERC721 contract address is always the message sender.\n     * @param operator The address which called `safeTransferFrom` function\n     * @param from The address which previously owned the token\n     * @param tokenId The NFT identifier which is being transferred\n     * @param data Additional data with no specified format\n     * @return bytes4 `bytes4(keccak256(\"onERC721Received(address,address,uint256,bytes)\"))`\n     */\n    function onERC721Received(address operator, address from, uint256 tokenId, bytes memory data)\n    public returns (bytes4);\n}\n\n// File: @openzeppelin/contracts/math/SafeMath.sol\n\npragma solidity ^0.5.0;\n\n/**\n * @dev Wrappers over Solidity's arithmetic operations with added overflow\n * checks.\n *\n * Arithmetic operations in Solidity wrap on overflow. This can easily result\n * in bugs, because programmers usually assume that an overflow raises an\n * error, which is the standard behavior in high level programming languages.\n * `SafeMath` restores this intuition by reverting the transaction when an\n * operation overflows.\n *\n * Using this library instead of the unchecked operations eliminates an entire\n * class of bugs, so it's recommended to use it always.\n */\nlibrary SafeMath {\n    /**\n     * @dev Returns the addition of two unsigned integers, reverting on\n     * overflow.\n     *\n     * Counterpart to Solidity's `+` operator.\n     *\n     * Requirements:\n     * - Addition cannot overflow.\n     */\n    function add(uint256 a, uint256 b) internal pure returns (uint256) {\n        uint256 c = a + b;\n        require(c >= a, \"SafeMath: addition overflow\");\n\n        return c;\n    }\n\n    /**\n     * @dev Returns the subtraction of two unsigned integers, reverting on\n     * overflow (when the result is negative).\n     *\n     * Counterpart to Solidity's `-` operator.\n     *\n     * Requirements:\n     * - Subtraction cannot overflow.\n     */\n    function sub(uint256 a, uint256 b) internal pure returns (uint256) {\n        require(b <= a, \"SafeMath: subtraction overflow\");\n        uint256 c = a - b;\n\n        return c;\n    }\n\n    /**\n     * @dev Returns the multiplication of two unsigned integers, reverting on\n     * overflow.\n     *\n     * Counterpart to Solidity's `*` operator.\n     *\n     * Requirements:\n     * - Multiplication cannot overflow.\n     */\n    function mul(uint256 a, uint256 b) internal pure returns (uint256) {\n        // Gas optimization: this is cheaper than requiring 'a' not being zero, but the\n        // benefit is lost if 'b' is also tested.\n        // See: https://github.com/OpenZeppelin/openzeppelin-contracts/pull/522\n        if (a == 0) {\n            return 0;\n        }\n\n        uint256 c = a * b;\n        require(c / a == b, \"SafeMath: multiplication overflow\");\n\n        return c;\n    }\n\n    /**\n     * @dev Returns the integer division of two unsigned integers. Reverts on\n     * division by zero. The result is rounded towards zero.\n     *\n     * Counterpart to Solidity's `/` operator. Note: this function uses a\n     * `revert` opcode (which leaves remaining gas untouched) while Solidity\n     * uses an invalid opcode to revert (consuming all remaining gas).\n     *\n     * Requirements:\n     * - The divisor cannot be zero.\n     */\n    function div(uint256 a, uint256 b) internal pure returns (uint256) {\n        // Solidity only automatically asserts when dividing by 0\n        require(b > 0, \"SafeMath: division by zero\");\n        uint256 c = a / b;\n        // assert(a == b * c + a % b); // There is no case in which this doesn't hold\n\n        return c;\n    }\n\n    /**\n     * @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo),\n     * Reverts when dividing by zero.\n     *\n     * Counterpart to Solidity's `%` operator. This function uses a `revert`\n     * opcode (which leaves remaining gas untouched) while Solidity uses an\n     * invalid opcode to revert (consuming all remaining gas).\n     *\n     * Requirements:\n     * - The divisor cannot be zero.\n     */\n    function mod(uint256 a, uint256 b) internal pure returns (uint256) {\n        require(b != 0, \"SafeMath: modulo by zero\");\n        return a % b;\n    }\n}\n\n// File: @openzeppelin/contracts/utils/Address.sol\n\npragma solidity ^0.5.0;\n\n/**\n * @dev Collection of functions related to the address type,\n */\nlibrary Address {\n    /**\n     * @dev Returns true if `account` is a contract.\n     *\n     * This test is non-exhaustive, and there may be false-negatives: during the\n     * execution of a contract's constructor, its address will be reported as\n     * not containing a contract.\n     *\n     * > It is unsafe to assume that an address for which this function returns\n     * false is an externally-owned account (EOA) and not a contract.\n     */\n    function isContract(address account) internal view returns (bool) {\n        // This method relies in extcodesize, which returns 0 for contracts in\n        // construction, since the code is only stored at the end of the\n        // constructor execution.\n\n        uint256 size;\n        // solhint-disable-next-line no-inline-assembly\n        assembly { size := extcodesize(account) }\n        return size > 0;\n    }\n}\n\n// File: @openzeppelin/contracts/drafts/Counters.sol\n\npragma solidity ^0.5.0;\n\n\n/**\n * @title Counters\n * @author Matt Condon (@shrugs)\n * @dev Provides counters that can only be incremented or decremented by one. This can be used e.g. to track the number\n * of elements in a mapping, issuing ERC721 ids, or counting request ids.\n *\n * Include with `using Counters for Counters.Counter;`\n * Since it is not possible to overflow a 256 bit integer with increments of one, `increment` can skip the SafeMath\n * overflow check, thereby saving gas. This does assume however correct usage, in that the underlying `_value` is never\n * directly accessed.\n */\nlibrary Counters {\n    using SafeMath for uint256;\n\n    struct Counter {\n        // This variable should never be directly accessed by users of the library: interactions must be restricted to\n        // the library's function. As of Solidity v0.5.2, this cannot be enforced, though there is a proposal to add\n        // this feature: see https://github.com/ethereum/solidity/issues/4637\n        uint256 _value; // default: 0\n    }\n\n    function current(Counter storage counter) internal view returns (uint256) {\n        return counter._value;\n    }\n\n    function increment(Counter storage counter) internal {\n        counter._value += 1;\n    }\n\n    function decrement(Counter storage counter) internal {\n        counter._value = counter._value.sub(1);\n    }\n}\n\n// File: @openzeppelin/contracts/introspection/ERC165.sol\n\npragma solidity ^0.5.0;\n\n\n/**\n * @dev Implementation of the `IERC165` interface.\n *\n * Contracts may inherit from this and call `_registerInterface` to declare\n * their support of an interface.\n */\ncontract ERC165 is IERC165 {\n    /*\n     * bytes4(keccak256('supportsInterface(bytes4)')) == 0x01ffc9a7\n     */\n    bytes4 private constant _INTERFACE_ID_ERC165 = 0x01ffc9a7;\n\n    /**\n     * @dev Mapping of interface ids to whether or not it's supported.\n     */\n    mapping(bytes4 => bool) private _supportedInterfaces;\n\n    constructor () internal {\n        // Derived contracts need only register support for their own interfaces,\n        // we register support for ERC165 itself here\n        _registerInterface(_INTERFACE_ID_ERC165);\n    }\n\n    /**\n     * @dev See `IERC165.supportsInterface`.\n     *\n     * Time complexity O(1), guaranteed to always use less than 30 000 gas.\n     */\n    function supportsInterface(bytes4 interfaceId) external view returns (bool) {\n        return _supportedInterfaces[interfaceId];\n    }\n\n    /**\n     * @dev Registers the contract as an implementer of the interface defined by\n     * `interfaceId`. Support of the actual ERC165 interface is automatic and\n     * registering its interface id is not required.\n     *\n     * See `IERC165.supportsInterface`.\n     *\n     * Requirements:\n     *\n     * - `interfaceId` cannot be the ERC165 invalid interface (`0xffffffff`).\n     */\n    function _registerInterface(bytes4 interfaceId) internal {\n        require(interfaceId != 0xffffffff, \"ERC165: invalid interface id\");\n        _supportedInterfaces[interfaceId] = true;\n    }\n}\n\n// File: @openzeppelin/contracts/token/ERC721/ERC721.sol\n\npragma solidity ^0.5.0;\n\n\n\n\n\n\n\n/**\n * @title ERC721 Non-Fungible Token Standard basic implementation\n * @dev see https://eips.ethereum.org/EIPS/eip-721\n */\ncontract ERC721 is ERC165, IERC721 {\n    using SafeMath for uint256;\n    using Address for address;\n    using Counters for Counters.Counter;\n\n    // Equals to `bytes4(keccak256(\"onERC721Received(address,address,uint256,bytes)\"))`\n    // which can be also obtained as `IERC721Receiver(0).onERC721Received.selector`\n    bytes4 private constant _ERC721_RECEIVED = 0x150b7a02;\n\n    // Mapping from token ID to owner\n    mapping (uint256 => address) private _tokenOwner;\n\n    // Mapping from token ID to approved address\n    mapping (uint256 => address) private _tokenApprovals;\n\n    // Mapping from owner to number of owned token\n    mapping (address => Counters.Counter) private _ownedTokensCount;\n\n    // Mapping from owner to operator approvals\n    mapping (address => mapping (address => bool)) private _operatorApprovals;\n\n    /*\n     *     bytes4(keccak256('balanceOf(address)')) == 0x70a08231\n     *     bytes4(keccak256('ownerOf(uint256)')) == 0x6352211e\n     *     bytes4(keccak256('approve(address,uint256)')) == 0x095ea7b3\n     *     bytes4(keccak256('getApproved(uint256)')) == 0x081812fc\n     *     bytes4(keccak256('setApprovalForAll(address,bool)')) == 0xa22cb465\n     *     bytes4(keccak256('isApprovedForAll(address,address)')) == 0xe985e9c\n     *     bytes4(keccak256('transferFrom(address,address,uint256)')) == 0x23b872dd\n     *     bytes4(keccak256('safeTransferFrom(address,address,uint256)')) == 0x42842e0e\n     *     bytes4(keccak256('safeTransferFrom(address,address,uint256,bytes)')) == 0xb88d4fde\n     *\n     *     => 0x70a08231 ^ 0x6352211e ^ 0x095ea7b3 ^ 0x081812fc ^\n     *        0xa22cb465 ^ 0xe985e9c ^ 0x23b872dd ^ 0x42842e0e ^ 0xb88d4fde == 0x80ac58cd\n     */\n    bytes4 private constant _INTERFACE_ID_ERC721 = 0x80ac58cd;\n\n    constructor () public {\n        // register the supported interfaces to conform to ERC721 via ERC165\n        _registerInterface(_INTERFACE_ID_ERC721);\n    }\n\n    /**\n     * @dev Gets the balance of the specified address.\n     * @param owner address to query the balance of\n     * @return uint256 representing the amount owned by the passed address\n     */\n    function balanceOf(address owner) public view returns (uint256) {\n        require(owner != address(0), \"ERC721: balance query for the zero address\");\n\n        return _ownedTokensCount[owner].current();\n    }\n\n    /**\n     * @dev Gets the owner of the specified token ID.\n     * @param tokenId uint256 ID of the token to query the owner of\n     * @return address currently marked as the owner of the given token ID\n     */\n    function ownerOf(uint256 tokenId) public view returns (address) {\n        address owner = _tokenOwner[tokenId];\n        require(owner != address(0), \"ERC721: owner query for nonexistent token\");\n\n        return owner;\n    }\n\n    /**\n     * @dev Approves another address to transfer the given token ID\n     * The zero address indicates there is no approved address.\n     * There can only be one approved address per token at a given time.\n     * Can only be called by the token owner or an approved operator.\n     * @param to address to be approved for the given token ID\n     * @param tokenId uint256 ID of the token to be approved\n     */\n    function approve(address to, uint256 tokenId) public {\n        address owner = ownerOf(tokenId);\n        require(to != owner, \"ERC721: approval to current owner\");\n\n        require(msg.sender == owner || isApprovedForAll(owner, msg.sender),\n            \"ERC721: approve caller is not owner nor approved for all\"\n        );\n\n        _tokenApprovals[tokenId] = to;\n        emit Approval(owner, to, tokenId);\n    }\n\n    /**\n     * @dev Gets the approved address for a token ID, or zero if no address set\n     * Reverts if the token ID does not exist.\n     * @param tokenId uint256 ID of the token to query the approval of\n     * @return address currently approved for the given token ID\n     */\n    function getApproved(uint256 tokenId) public view returns (address) {\n        require(_exists(tokenId), \"ERC721: approved query for nonexistent token\");\n\n        return _tokenApprovals[tokenId];\n    }\n\n    /**\n     * @dev Sets or unsets the approval of a given operator\n     * An operator is allowed to transfer all tokens of the sender on their behalf.\n     * @param to operator address to set the approval\n     * @param approved representing the status of the approval to be set\n     */\n    function setApprovalForAll(address to, bool approved) public {\n        require(to != msg.sender, \"ERC721: approve to caller\");\n\n        _operatorApprovals[msg.sender][to] = approved;\n        emit ApprovalForAll(msg.sender, to, approved);\n    }\n\n    /**\n     * @dev Tells whether an operator is approved by a given owner.\n     * @param owner owner address which you want to query the approval of\n     * @param operator operator address which you want to query the approval of\n     * @return bool whether the given operator is approved by the given owner\n     */\n    function isApprovedForAll(address owner, address operator) public view returns (bool) {\n        return _operatorApprovals[owner][operator];\n    }\n\n    /**\n     * @dev Transfers the ownership of a given token ID to another address.\n     * Usage of this method is discouraged, use `safeTransferFrom` whenever possible.\n     * Requires the msg.sender to be the owner, approved, or operator.\n     * @param from current owner of the token\n     * @param to address to receive the ownership of the given token ID\n     * @param tokenId uint256 ID of the token to be transferred\n     */\n    function transferFrom(address from, address to, uint256 tokenId) public {\n        //solhint-disable-next-line max-line-length\n        require(_isApprovedOrOwner(msg.sender, tokenId), \"ERC721: transfer caller is not owner nor approved\");\n\n        _transferFrom(from, to, tokenId);\n    }\n\n    /**\n     * @dev Safely transfers the ownership of a given token ID to another address\n     * If the target address is a contract, it must implement `onERC721Received`,\n     * which is called upon a safe transfer, and return the magic value\n     * `bytes4(keccak256(\"onERC721Received(address,address,uint256,bytes)\"))`; otherwise,\n     * the transfer is reverted.\n     * Requires the msg.sender to be the owner, approved, or operator\n     * @param from current owner of the token\n     * @param to address to receive the ownership of the given token ID\n     * @param tokenId uint256 ID of the token to be transferred\n     */\n    function safeTransferFrom(address from, address to, uint256 tokenId) public {\n        safeTransferFrom(from, to, tokenId, \"\");\n    }\n\n    /**\n     * @dev Safely transfers the ownership of a given token ID to another address\n     * If the target address is a contract, it must implement `onERC721Received`,\n     * which is called upon a safe transfer, and return the magic value\n     * `bytes4(keccak256(\"onERC721Received(address,address,uint256,bytes)\"))`; otherwise,\n     * the transfer is reverted.\n     * Requires the msg.sender to be the owner, approved, or operator\n     * @param from current owner of the token\n     * @param to address to receive the ownership of the given token ID\n     * @param tokenId uint256 ID of the token to be transferred\n     * @param _data bytes data to send along with a safe transfer check\n     */\n    function safeTransferFrom(address from, address to, uint256 tokenId, bytes memory _data) public {\n        transferFrom(from, to, tokenId);\n        require(_checkOnERC721Received(from, to, tokenId, _data), \"ERC721: transfer to non ERC721Receiver implementer\");\n    }\n\n    /**\n     * @dev Returns whether the specified token exists.\n     * @param tokenId uint256 ID of the token to query the existence of\n     * @return bool whether the token exists\n     */\n    function _exists(uint256 tokenId) internal view returns (bool) {\n        address owner = _tokenOwner[tokenId];\n        return owner != address(0);\n    }\n\n    /**\n     * @dev Returns whether the given spender can transfer a given token ID.\n     * @param spender address of the spender to query\n     * @param tokenId uint256 ID of the token to be transferred\n     * @return bool whether the msg.sender is approved for the given token ID,\n     * is an operator of the owner, or is the owner of the token\n     */\n    function _isApprovedOrOwner(address spender, uint256 tokenId) internal view returns (bool) {\n        require(_exists(tokenId), \"ERC721: operator query for nonexistent token\");\n        address owner = ownerOf(tokenId);\n        return (spender == owner || getApproved(tokenId) == spender || isApprovedForAll(owner, spender));\n    }\n\n    /**\n     * @dev Internal function to mint a new token.\n     * Reverts if the given token ID already exists.\n     * @param to The address that will own the minted token\n     * @param tokenId uint256 ID of the token to be minted\n     */\n    function _mint(address to, uint256 tokenId) internal {\n        require(to != address(0), \"ERC721: mint to the zero address\");\n        require(!_exists(tokenId), \"ERC721: token already minted\");\n\n        _tokenOwner[tokenId] = to;\n        _ownedTokensCount[to].increment();\n\n        emit Transfer(address(0), to, tokenId);\n    }\n\n    /**\n     * @dev Internal function to burn a specific token.\n     * Reverts if the token does not exist.\n     * Deprecated, use _burn(uint256) instead.\n     * @param owner owner of the token to burn\n     * @param tokenId uint256 ID of the token being burned\n     */\n    function _burn(address owner, uint256 tokenId) internal {\n        require(ownerOf(tokenId) == owner, \"ERC721: burn of token that is not own\");\n\n        _clearApproval(tokenId);\n\n        _ownedTokensCount[owner].decrement();\n        _tokenOwner[tokenId] = address(0);\n\n        emit Transfer(owner, address(0), tokenId);\n    }\n\n    /**\n     * @dev Internal function to burn a specific token.\n     * Reverts if the token does not exist.\n     * @param tokenId uint256 ID of the token being burned\n     */\n    function _burn(uint256 tokenId) internal {\n        _burn(ownerOf(tokenId), tokenId);\n    }\n\n    /**\n     * @dev Internal function to transfer ownership of a given token ID to another address.\n     * As opposed to transferFrom, this imposes no restrictions on msg.sender.\n     * @param from current owner of the token\n     * @param to address to receive the ownership of the given token ID\n     * @param tokenId uint256 ID of the token to be transferred\n     */\n    function _transferFrom(address from, address to, uint256 tokenId) internal {\n        require(ownerOf(tokenId) == from, \"ERC721: transfer of token that is not own\");\n        require(to != address(0), \"ERC721: transfer to the zero address\");\n\n        _clearApproval(tokenId);\n\n        _ownedTokensCount[from].decrement();\n        _ownedTokensCount[to].increment();\n\n        _tokenOwner[tokenId] = to;\n\n        emit Transfer(from, to, tokenId);\n    }\n\n    /**\n     * @dev Internal function to invoke `onERC721Received` on a target address.\n     * The call is not executed if the target address is not a contract.\n     *\n     * This function is deprecated.\n     * @param from address representing the previous owner of the given token ID\n     * @param to target address that will receive the tokens\n     * @param tokenId uint256 ID of the token to be transferred\n     * @param _data bytes optional data to send along with the call\n     * @return bool whether the call correctly returned the expected magic value\n     */\n    function _checkOnERC721Received(address from, address to, uint256 tokenId, bytes memory _data)\n        internal returns (bool)\n    {\n        if (!to.isContract()) {\n            return true;\n        }\n\n        bytes4 retval = IERC721Receiver(to).onERC721Received(msg.sender, from, tokenId, _data);\n        return (retval == _ERC721_RECEIVED);\n    }\n\n    /**\n     * @dev Private function to clear current approval of a given token ID.\n     * @param tokenId uint256 ID of the token to be transferred\n     */\n    function _clearApproval(uint256 tokenId) private {\n        if (_tokenApprovals[tokenId] != address(0)) {\n            _tokenApprovals[tokenId] = address(0);\n        }\n    }\n}\n\n// File: @openzeppelin/contracts/token/ERC721/IERC721Enumerable.sol\n\npragma solidity ^0.5.0;\n\n\n/**\n * @title ERC-721 Non-Fungible Token Standard, optional enumeration extension\n * @dev See https://eips.ethereum.org/EIPS/eip-721\n */\ncontract IERC721Enumerable is IERC721 {\n    function totalSupply() public view returns (uint256);\n    function tokenOfOwnerByIndex(address owner, uint256 index) public view returns (uint256 tokenId);\n\n    function tokenByIndex(uint256 index) public view returns (uint256);\n}\n\n// File: @openzeppelin/contracts/token/ERC721/ERC721Enumerable.sol\n\npragma solidity ^0.5.0;\n\n\n\n\n/**\n * @title ERC-721 Non-Fungible Token with optional enumeration extension logic\n * @dev See https://eips.ethereum.org/EIPS/eip-721\n */\ncontract ERC721Enumerable is ERC165, ERC721, IERC721Enumerable {\n    // Mapping from owner to list of owned token IDs\n    mapping(address => uint256[]) private _ownedTokens;\n\n    // Mapping from token ID to index of the owner tokens list\n    mapping(uint256 => uint256) private _ownedTokensIndex;\n\n    // Array with all token ids, used for enumeration\n    uint256[] private _allTokens;\n\n    // Mapping from token id to position in the allTokens array\n    mapping(uint256 => uint256) private _allTokensIndex;\n\n    /*\n     *     bytes4(keccak256('totalSupply()')) == 0x18160ddd\n     *     bytes4(keccak256('tokenOfOwnerByIndex(address,uint256)')) == 0x2f745c59\n     *     bytes4(keccak256('tokenByIndex(uint256)')) == 0x4f6ccce7\n     *\n     *     => 0x18160ddd ^ 0x2f745c59 ^ 0x4f6ccce7 == 0x780e9d63\n     */\n    bytes4 private constant _INTERFACE_ID_ERC721_ENUMERABLE = 0x780e9d63;\n\n    /**\n     * @dev Constructor function.\n     */\n    constructor () public {\n        // register the supported interface to conform to ERC721Enumerable via ERC165\n        _registerInterface(_INTERFACE_ID_ERC721_ENUMERABLE);\n    }\n\n    /**\n     * @dev Gets the token ID at a given index of the tokens list of the requested owner.\n     * @param owner address owning the tokens list to be accessed\n     * @param index uint256 representing the index to be accessed of the requested tokens list\n     * @return uint256 token ID at the given index of the tokens list owned by the requested address\n     */\n    function tokenOfOwnerByIndex(address owner, uint256 index) public view returns (uint256) {\n        require(index < balanceOf(owner), \"ERC721Enumerable: owner index out of bounds\");\n        return _ownedTokens[owner][index];\n    }\n\n    /**\n     * @dev Gets the total amount of tokens stored by the contract.\n     * @return uint256 representing the total amount of tokens\n     */\n    function totalSupply() public view returns (uint256) {\n        return _allTokens.length;\n    }\n\n    /**\n     * @dev Gets the token ID at a given index of all the tokens in this contract\n     * Reverts if the index is greater or equal to the total number of tokens.\n     * @param index uint256 representing the index to be accessed of the tokens list\n     * @return uint256 token ID at the given index of the tokens list\n     */\n    function tokenByIndex(uint256 index) public view returns (uint256) {\n        require(index < totalSupply(), \"ERC721Enumerable: global index out of bounds\");\n        return _allTokens[index];\n    }\n\n    /**\n     * @dev Internal function to transfer ownership of a given token ID to another address.\n     * As opposed to transferFrom, this imposes no restrictions on msg.sender.\n     * @param from current owner of the token\n     * @param to address to receive the ownership of the given token ID\n     * @param tokenId uint256 ID of the token to be transferred\n     */\n    function _transferFrom(address from, address to, uint256 tokenId) internal {\n        super._transferFrom(from, to, tokenId);\n\n        _removeTokenFromOwnerEnumeration(from, tokenId);\n\n        _addTokenToOwnerEnumeration(to, tokenId);\n    }\n\n    /**\n     * @dev Internal function to mint a new token.\n     * Reverts if the given token ID already exists.\n     * @param to address the beneficiary that will own the minted token\n     * @param tokenId uint256 ID of the token to be minted\n     */\n    function _mint(address to, uint256 tokenId) internal {\n        super._mint(to, tokenId);\n\n        _addTokenToOwnerEnumeration(to, tokenId);\n\n        _addTokenToAllTokensEnumeration(tokenId);\n    }\n\n    /**\n     * @dev Internal function to burn a specific token.\n     * Reverts if the token does not exist.\n     * Deprecated, use _burn(uint256) instead.\n     * @param owner owner of the token to burn\n     * @param tokenId uint256 ID of the token being burned\n     */\n    function _burn(address owner, uint256 tokenId) internal {\n        super._burn(owner, tokenId);\n\n        _removeTokenFromOwnerEnumeration(owner, tokenId);\n        // Since tokenId will be deleted, we can clear its slot in _ownedTokensIndex to trigger a gas refund\n        _ownedTokensIndex[tokenId] = 0;\n\n        _removeTokenFromAllTokensEnumeration(tokenId);\n    }\n\n    /**\n     * @dev Gets the list of token IDs of the requested owner.\n     * @param owner address owning the tokens\n     * @return uint256[] List of token IDs owned by the requested address\n     */\n    function _tokensOfOwner(address owner) internal view returns (uint256[] storage) {\n        return _ownedTokens[owner];\n    }\n\n    /**\n     * @dev Private function to add a token to this extension's ownership-tracking data structures.\n     * @param to address representing the new owner of the given token ID\n     * @param tokenId uint256 ID of the token to be added to the tokens list of the given address\n     */\n    function _addTokenToOwnerEnumeration(address to, uint256 tokenId) private {\n        _ownedTokensIndex[tokenId] = _ownedTokens[to].length;\n        _ownedTokens[to].push(tokenId);\n    }\n\n    /**\n     * @dev Private function to add a token to this extension's token tracking data structures.\n     * @param tokenId uint256 ID of the token to be added to the tokens list\n     */\n    function _addTokenToAllTokensEnumeration(uint256 tokenId) private {\n        _allTokensIndex[tokenId] = _allTokens.length;\n        _allTokens.push(tokenId);\n    }\n\n    /**\n     * @dev Private function to remove a token from this extension's ownership-tracking data structures. Note that\n     * while the token is not assigned a new owner, the _ownedTokensIndex mapping is _not_ updated: this allows for\n     * gas optimizations e.g. when performing a transfer operation (avoiding double writes).\n     * This has O(1) time complexity, but alters the order of the _ownedTokens array.\n     * @param from address representing the previous owner of the given token ID\n     * @param tokenId uint256 ID of the token to be removed from the tokens list of the given address\n     */\n    function _removeTokenFromOwnerEnumeration(address from, uint256 tokenId) private {\n        // To prevent a gap in from's tokens array, we store the last token in the index of the token to delete, and\n        // then delete the last slot (swap and pop).\n\n        uint256 lastTokenIndex = _ownedTokens[from].length.sub(1);\n        uint256 tokenIndex = _ownedTokensIndex[tokenId];\n\n        // When the token to delete is the last token, the swap operation is unnecessary\n        if (tokenIndex != lastTokenIndex) {\n            uint256 lastTokenId = _ownedTokens[from][lastTokenIndex];\n\n            _ownedTokens[from][tokenIndex] = lastTokenId; // Move the last token to the slot of the to-delete token\n            _ownedTokensIndex[lastTokenId] = tokenIndex; // Update the moved token's index\n        }\n\n        // This also deletes the contents at the last position of the array\n        _ownedTokens[from].length--;\n\n        // Note that _ownedTokensIndex[tokenId] hasn't been cleared: it still points to the old slot (now occupied by\n        // lastTokenId, or just over the end of the array if the token was the last one).\n    }\n\n    /**\n     * @dev Private function to remove a token from this extension's token tracking data structures.\n     * This has O(1) time complexity, but alters the order of the _allTokens array.\n     * @param tokenId uint256 ID of the token to be removed from the tokens list\n     */\n    function _removeTokenFromAllTokensEnumeration(uint256 tokenId) private {\n        // To prevent a gap in the tokens array, we store the last token in the index of the token to delete, and\n        // then delete the last slot (swap and pop).\n\n        uint256 lastTokenIndex = _allTokens.length.sub(1);\n        uint256 tokenIndex = _allTokensIndex[tokenId];\n\n        // When the token to delete is the last token, the swap operation is unnecessary. However, since this occurs so\n        // rarely (when the last minted token is burnt) that we still do the swap here to avoid the gas cost of adding\n        // an 'if' statement (like in _removeTokenFromOwnerEnumeration)\n        uint256 lastTokenId = _allTokens[lastTokenIndex];\n\n        _allTokens[tokenIndex] = lastTokenId; // Move the last token to the slot of the to-delete token\n        _allTokensIndex[lastTokenId] = tokenIndex; // Update the moved token's index\n\n        // This also deletes the contents at the last position of the array\n        _allTokens.length--;\n        _allTokensIndex[tokenId] = 0;\n    }\n}\n\n// File: @openzeppelin/contracts/token/ERC721/IERC721Metadata.sol\n\npragma solidity ^0.5.0;\n\n\n/**\n * @title ERC-721 Non-Fungible Token Standard, optional metadata extension\n * @dev See https://eips.ethereum.org/EIPS/eip-721\n */\ncontract IERC721Metadata is IERC721 {\n    function name() external view returns (string memory);\n    function symbol() external view returns (string memory);\n    function tokenURI(uint256 tokenId) external view returns (string memory);\n}\n\n// File: @openzeppelin/contracts/token/ERC721/ERC721Metadata.sol\n\npragma solidity ^0.5.0;\n\n\n\n\ncontract ERC721Metadata is ERC165, ERC721, IERC721Metadata {\n    // Token name\n    string private _name;\n\n    // Token symbol\n    string private _symbol;\n\n    // Optional mapping for token URIs\n    mapping(uint256 => string) private _tokenURIs;\n\n    /*\n     *     bytes4(keccak256('name()')) == 0x06fdde03\n     *     bytes4(keccak256('symbol()')) == 0x95d89b41\n     *     bytes4(keccak256('tokenURI(uint256)')) == 0xc87b56dd\n     *\n     *     => 0x06fdde03 ^ 0x95d89b41 ^ 0xc87b56dd == 0x5b5e139f\n     */\n    bytes4 private constant _INTERFACE_ID_ERC721_METADATA = 0x5b5e139f;\n\n    /**\n     * @dev Constructor function\n     */\n    constructor (string memory name, string memory symbol) public {\n        _name = name;\n        _symbol = symbol;\n\n        // register the supported interfaces to conform to ERC721 via ERC165\n        _registerInterface(_INTERFACE_ID_ERC721_METADATA);\n    }\n\n    /**\n     * @dev Gets the token name.\n     * @return string representing the token name\n     */\n    function name() external view returns (string memory) {\n        return _name;\n    }\n\n    /**\n     * @dev Gets the token symbol.\n     * @return string representing the token symbol\n     */\n    function symbol() external view returns (string memory) {\n        return _symbol;\n    }\n\n    /**\n     * @dev Returns an URI for a given token ID.\n     * Throws if the token ID does not exist. May return an empty string.\n     * @param tokenId uint256 ID of the token to query\n     */\n    function tokenURI(uint256 tokenId) external view returns (string memory) {\n        require(_exists(tokenId), \"ERC721Metadata: URI query for nonexistent token\");\n        return _tokenURIs[tokenId];\n    }\n\n    /**\n     * @dev Internal function to set the token URI for a given token.\n     * Reverts if the token ID does not exist.\n     * @param tokenId uint256 ID of the token to set its URI\n     * @param uri string URI to assign\n     */\n    function _setTokenURI(uint256 tokenId, string memory uri) internal {\n        require(_exists(tokenId), \"ERC721Metadata: URI set of nonexistent token\");\n        _tokenURIs[tokenId] = uri;\n    }\n\n    /**\n     * @dev Internal function to burn a specific token.\n     * Reverts if the token does not exist.\n     * Deprecated, use _burn(uint256) instead.\n     * @param owner owner of the token to burn\n     * @param tokenId uint256 ID of the token being burned by the msg.sender\n     */\n    function _burn(address owner, uint256 tokenId) internal {\n        super._burn(owner, tokenId);\n\n        // Clear metadata (if any)\n        if (bytes(_tokenURIs[tokenId]).length != 0) {\n            delete _tokenURIs[tokenId];\n        }\n    }\n}\n\n// File: @openzeppelin/contracts/token/ERC721/ERC721Full.sol\n\npragma solidity ^0.5.0;\n\n\n\n\n/**\n * @title Full ERC721 Token\n * This implementation includes all the required and some optional functionality of the ERC721 standard\n * Moreover, it includes approve all functionality using operator terminology\n * @dev see https://eips.ethereum.org/EIPS/eip-721\n */\ncontract ERC721Full is ERC721, ERC721Enumerable, ERC721Metadata {\n    constructor (string memory name, string memory symbol) public ERC721Metadata(name, symbol) {\n        // solhint-disable-previous-line no-empty-blocks\n    }\n}\n",
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+                          "typeIdentifier": "t_mapping$_t_uint256_$_t_address_$",
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+                          "typeString": "uint256"
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+                        "typeString": "address"
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+                        "name": "from",
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+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        }
+                      },
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+                        "name": "to",
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+                        "typeDescriptions": {
+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        }
+                      },
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+                        "src": "22780:7:1",
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+                          "typeString": "uint256"
+                        }
+                      }
+                    ],
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+                      "argumentTypes": [
+                        {
+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        },
+                        {
+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        },
+                        {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      ],
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+                      "name": "Transfer",
+                      "nodeType": "Identifier",
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+                      }
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+                  "nodeType": "EmitStatement",
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+                }
+              ]
+            },
+            "documentation": "@dev Internal function to transfer ownership of a given token ID to another address.\nAs opposed to transferFrom, this imposes no restrictions on msg.sender.\n@param from current owner of the token\n@param to address to receive the ownership of the given token ID\n@param tokenId uint256 ID of the token to be transferred",
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+                    "typeString": "address"
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+                      "typeIdentifier": "t_address",
+                      "typeString": "address"
+                    }
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+                    "typeString": "address"
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+                    "name": "address",
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+                      "typeString": "address"
+                    }
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+            "visibility": "internal"
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+                          "name": "to",
+                          "nodeType": "Identifier",
+                          "overloadedDeclarations": [],
+                          "referencedDeclaration": 884,
+                          "src": "23514:2:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_address",
+                            "typeString": "address"
+                          }
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+                        "src": "23514:13:1",
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+                        "name": "bytes4",
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+                          "typeIdentifier": "t_bytes4",
+                          "typeString": "bytes4"
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+                        "expression": {
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+                          "id": 907,
+                          "name": "msg",
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+                          "src": "23630:3:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_magic_message",
+                            "typeString": "msg"
+                          }
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+                        "isLValue": false,
+                        "isPure": false,
+                        "lValueRequested": false,
+                        "memberName": "sender",
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+                        "src": "23630:10:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_address_payable",
+                          "typeString": "address payable"
+                        }
+                      },
+                      {
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+                        "id": 909,
+                        "name": "from",
+                        "nodeType": "Identifier",
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+                        "src": "23642:4:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        }
+                      },
+                      {
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+                        "id": 910,
+                        "name": "tokenId",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
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+                        "src": "23648:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      },
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+                        "id": 911,
+                        "name": "_data",
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+                        "src": "23657:5:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_bytes_memory_ptr",
+                          "typeString": "bytes memory"
+                        }
+                      }
+                    ],
+                    "expression": {
+                      "argumentTypes": [
+                        {
+                          "typeIdentifier": "t_address_payable",
+                          "typeString": "address payable"
+                        },
+                        {
+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        },
+                        {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        },
+                        {
+                          "typeIdentifier": "t_bytes_memory_ptr",
+                          "typeString": "bytes memory"
+                        }
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+                        "arguments": [
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+                            "id": 904,
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+                            "src": "23609:2:1",
+                            "typeDescriptions": {
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+                              "typeString": "address"
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+                              "typeIdentifier": "t_address",
+                              "typeString": "address"
+                            }
+                          ],
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+                          "name": "IERC721Receiver",
+                          "nodeType": "Identifier",
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+                          "referencedDeclaration": 139,
+                          "src": "23593:15:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_type$_t_contract$_IERC721Receiver_$139_$",
+                            "typeString": "type(contract IERC721Receiver)"
+                          }
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+                        "isLValue": false,
+                        "isPure": false,
+                        "kind": "typeConversion",
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+                        "typeDescriptions": {
+                          "typeIdentifier": "t_contract$_IERC721Receiver_$139",
+                          "typeString": "contract IERC721Receiver"
+                        }
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+                      "memberName": "onERC721Received",
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+                      "src": "23593:36:1",
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+                        "typeString": "function (address,address,uint256,bytes memory) external returns (bytes4)"
+                      }
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+                      "typeString": "bytes4"
+                    }
+                  },
+                  "nodeType": "VariableDeclarationStatement",
+                  "src": "23577:86:1"
+                },
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+                    "components": [
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+                        "argumentTypes": null,
+                        "commonType": {
+                          "typeIdentifier": "t_bytes4",
+                          "typeString": "bytes4"
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+                        "lValueRequested": false,
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+                          "name": "retval",
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+                          "overloadedDeclarations": [],
+                          "referencedDeclaration": 902,
+                          "src": "23681:6:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_bytes4",
+                            "typeString": "bytes4"
+                          }
+                        },
+                        "nodeType": "BinaryOperation",
+                        "operator": "==",
+                        "rightExpression": {
+                          "argumentTypes": null,
+                          "id": 915,
+                          "name": "_ERC721_RECEIVED",
+                          "nodeType": "Identifier",
+                          "overloadedDeclarations": [],
+                          "referencedDeclaration": 403,
+                          "src": "23691:16:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_bytes4",
+                            "typeString": "bytes4"
+                          }
+                        },
+                        "src": "23681:26:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_bool",
+                          "typeString": "bool"
+                        }
+                      }
+                    ],
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+                    "isConstant": false,
+                    "isInlineArray": false,
+                    "isLValue": false,
+                    "isPure": false,
+                    "lValueRequested": false,
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+                    "src": "23680:28:1",
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+                  },
+                  "functionReturnParameters": 892,
+                  "id": 918,
+                  "nodeType": "Return",
+                  "src": "23673:35:1"
+                }
+              ]
+            },
+            "documentation": "@dev Internal function to invoke `onERC721Received` on a target address.\nThe call is not executed if the target address is not a contract.\n     * This function is deprecated.\n@param from address representing the previous owner of the given token ID\n@param to target address that will receive the tokens\n@param tokenId uint256 ID of the token to be transferred\n@param _data bytes optional data to send along with the call\n@return bool whether the call correctly returned the expected magic value",
+            "id": 920,
+            "implemented": true,
+            "kind": "function",
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+            "name": "_checkOnERC721Received",
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+                  "scope": 920,
+                  "src": "23400:12:1",
+                  "stateVariable": false,
+                  "storageLocation": "default",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_address",
+                    "typeString": "address"
+                  },
+                  "typeName": {
+                    "id": 881,
+                    "name": "address",
+                    "nodeType": "ElementaryTypeName",
+                    "src": "23400:7:1",
+                    "stateMutability": "nonpayable",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_address",
+                      "typeString": "address"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                },
+                {
+                  "constant": false,
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+                      "src": "27266:10:1",
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+                        "src": "27780:7:1",
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+                          "typeString": "uint256"
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+                          "typeString": "address"
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+                          "typeString": "address"
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+                        {
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+                          "typeString": "uint256"
+                        }
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+                      "typeString": "tuple()"
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+                        "nodeType": "Identifier",
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+                        "src": "28342:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
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+                        {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
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+                      "name": "_addTokenToAllTokensEnumeration",
+                      "nodeType": "Identifier",
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+                      "src": "28310:31:1",
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+                        "typeString": "function (uint256)"
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+                }
+              ]
+            },
+            "documentation": "@dev Internal function to mint a new token.\nReverts if the given token ID already exists.\n@param to address the beneficiary that will own the minted token\n@param tokenId uint256 ID of the token to be minted",
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+                  "stateVariable": false,
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+                    "typeString": "address"
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+                    "name": "address",
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+                      "typeIdentifier": "t_address",
+                      "typeString": "address"
+                    }
+                  },
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+                  "src": "28188:15:1",
+                  "stateVariable": false,
+                  "storageLocation": "default",
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+                    "typeString": "uint256"
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+                      "typeString": "uint256"
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+                  "visibility": "internal"
+                }
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+            "visibility": "internal"
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+                        "name": "owner",
+                        "nodeType": "Identifier",
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+                        "src": "28710:5:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        }
+                      },
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+                        "id": 1120,
+                        "name": "tokenId",
+                        "nodeType": "Identifier",
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+                        "referencedDeclaration": 1113,
+                        "src": "28717:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
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+                      "argumentTypes": [
+                        {
+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        },
+                        {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      ],
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+                        "id": 1116,
+                        "name": "super",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 1572,
+                        "src": "28698:5:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_super$_ERC721Enumerable_$1302",
+                          "typeString": "contract super ERC721Enumerable"
+                        }
+                      },
+                      "id": 1118,
+                      "isConstant": false,
+                      "isLValue": false,
+                      "isPure": false,
+                      "lValueRequested": false,
+                      "memberName": "_burn",
+                      "nodeType": "MemberAccess",
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+                      "src": "28698:11:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_function_internal_nonpayable$_t_address_$_t_uint256_$returns$__$",
+                        "typeString": "function (address,uint256)"
+                      }
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+                    "kind": "functionCall",
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+                    "nodeType": "FunctionCall",
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+                      "typeString": "tuple()"
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+                        "id": 1124,
+                        "name": "owner",
+                        "nodeType": "Identifier",
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+                        "src": "28769:5:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        }
+                      },
+                      {
+                        "argumentTypes": null,
+                        "id": 1125,
+                        "name": "tokenId",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 1113,
+                        "src": "28776:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      }
+                    ],
+                    "expression": {
+                      "argumentTypes": [
+                        {
+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        },
+                        {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      ],
+                      "id": 1123,
+                      "name": "_removeTokenFromOwnerEnumeration",
+                      "nodeType": "Identifier",
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+                      "referencedDeclaration": 1252,
+                      "src": "28736:32:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_function_internal_nonpayable$_t_address_$_t_uint256_$returns$__$",
+                        "typeString": "function (address,uint256)"
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+                    "isLValue": false,
+                    "isPure": false,
+                    "kind": "functionCall",
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+                    "nodeType": "FunctionCall",
+                    "src": "28736:48:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_tuple$__$",
+                      "typeString": "tuple()"
+                    }
+                  },
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+                  "nodeType": "ExpressionStatement",
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+                },
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+                      "baseExpression": {
+                        "argumentTypes": null,
+                        "id": 1128,
+                        "name": "_ownedTokensIndex",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 985,
+                        "src": "28903:17:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_mapping$_t_uint256_$_t_uint256_$",
+                          "typeString": "mapping(uint256 => uint256)"
+                        }
+                      },
+                      "id": 1130,
+                      "indexExpression": {
+                        "argumentTypes": null,
+                        "id": 1129,
+                        "name": "tokenId",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 1113,
+                        "src": "28921:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      },
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+                      "isLValue": true,
+                      "isPure": false,
+                      "lValueRequested": true,
+                      "nodeType": "IndexAccess",
+                      "src": "28903:26:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_uint256",
+                        "typeString": "uint256"
+                      }
+                    },
+                    "nodeType": "Assignment",
+                    "operator": "=",
+                    "rightHandSide": {
+                      "argumentTypes": null,
+                      "hexValue": "30",
+                      "id": 1131,
+                      "isConstant": false,
+                      "isLValue": false,
+                      "isPure": true,
+                      "kind": "number",
+                      "lValueRequested": false,
+                      "nodeType": "Literal",
+                      "src": "28932:1:1",
+                      "subdenomination": null,
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_rational_0_by_1",
+                        "typeString": "int_const 0"
+                      },
+                      "value": "0"
+                    },
+                    "src": "28903:30:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_uint256",
+                      "typeString": "uint256"
+                    }
+                  },
+                  "id": 1133,
+                  "nodeType": "ExpressionStatement",
+                  "src": "28903:30:1"
+                },
+                {
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+                    "arguments": [
+                      {
+                        "argumentTypes": null,
+                        "id": 1135,
+                        "name": "tokenId",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 1113,
+                        "src": "28981:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      }
+                    ],
+                    "expression": {
+                      "argumentTypes": [
+                        {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      ],
+                      "id": 1134,
+                      "name": "_removeTokenFromAllTokensEnumeration",
+                      "nodeType": "Identifier",
+                      "overloadedDeclarations": [],
+                      "referencedDeclaration": 1301,
+                      "src": "28944:36:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_function_internal_nonpayable$_t_uint256_$returns$__$",
+                        "typeString": "function (uint256)"
+                      }
+                    },
+                    "id": 1136,
+                    "isConstant": false,
+                    "isLValue": false,
+                    "isPure": false,
+                    "kind": "functionCall",
+                    "lValueRequested": false,
+                    "names": [],
+                    "nodeType": "FunctionCall",
+                    "src": "28944:45:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_tuple$__$",
+                      "typeString": "tuple()"
+                    }
+                  },
+                  "id": 1137,
+                  "nodeType": "ExpressionStatement",
+                  "src": "28944:45:1"
+                }
+              ]
+            },
+            "documentation": "@dev Internal function to burn a specific token.\nReverts if the token does not exist.\nDeprecated, use _burn(uint256) instead.\n@param owner owner of the token to burn\n@param tokenId uint256 ID of the token being burned",
+            "id": 1139,
+            "implemented": true,
+            "kind": "function",
+            "modifiers": [],
+            "name": "_burn",
+            "nodeType": "FunctionDefinition",
+            "parameters": {
+              "id": 1114,
+              "nodeType": "ParameterList",
+              "parameters": [
+                {
+                  "constant": false,
+                  "id": 1111,
+                  "name": "owner",
+                  "nodeType": "VariableDeclaration",
+                  "scope": 1139,
+                  "src": "28647:13:1",
+                  "stateVariable": false,
+                  "storageLocation": "default",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_address",
+                    "typeString": "address"
+                  },
+                  "typeName": {
+                    "id": 1110,
+                    "name": "address",
+                    "nodeType": "ElementaryTypeName",
+                    "src": "28647:7:1",
+                    "stateMutability": "nonpayable",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_address",
+                      "typeString": "address"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                },
+                {
+                  "constant": false,
+                  "id": 1113,
+                  "name": "tokenId",
+                  "nodeType": "VariableDeclaration",
+                  "scope": 1139,
+                  "src": "28662:15:1",
+                  "stateVariable": false,
+                  "storageLocation": "default",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_uint256",
+                    "typeString": "uint256"
+                  },
+                  "typeName": {
+                    "id": 1112,
+                    "name": "uint256",
+                    "nodeType": "ElementaryTypeName",
+                    "src": "28662:7:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_uint256",
+                      "typeString": "uint256"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                }
+              ],
+              "src": "28646:32:1"
+            },
+            "returnParameters": {
+              "id": 1115,
+              "nodeType": "ParameterList",
+              "parameters": [],
+              "src": "28688:0:1"
+            },
+            "scope": 1302,
+            "src": "28632:364:1",
+            "stateMutability": "nonpayable",
+            "superFunction": 811,
+            "visibility": "internal"
+          },
+          {
+            "body": {
+              "id": 1151,
+              "nodeType": "Block",
+              "src": "29282:43:1",
+              "statements": [
+                {
+                  "expression": {
+                    "argumentTypes": null,
+                    "baseExpression": {
+                      "argumentTypes": null,
+                      "id": 1147,
+                      "name": "_ownedTokens",
+                      "nodeType": "Identifier",
+                      "overloadedDeclarations": [],
+                      "referencedDeclaration": 981,
+                      "src": "29299:12:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_mapping$_t_address_$_t_array$_t_uint256_$dyn_storage_$",
+                        "typeString": "mapping(address => uint256[] storage ref)"
+                      }
+                    },
+                    "id": 1149,
+                    "indexExpression": {
+                      "argumentTypes": null,
+                      "id": 1148,
+                      "name": "owner",
+                      "nodeType": "Identifier",
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+                      "referencedDeclaration": 1141,
+                      "src": "29312:5:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_address",
+                        "typeString": "address"
+                      }
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+                    "isLValue": true,
+                    "isPure": false,
+                    "lValueRequested": false,
+                    "nodeType": "IndexAccess",
+                    "src": "29299:19:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_array$_t_uint256_$dyn_storage",
+                      "typeString": "uint256[] storage ref"
+                    }
+                  },
+                  "functionReturnParameters": 1146,
+                  "id": 1150,
+                  "nodeType": "Return",
+                  "src": "29292:26:1"
+                }
+              ]
+            },
+            "documentation": "@dev Gets the list of token IDs of the requested owner.\n@param owner address owning the tokens\n@return uint256[] List of token IDs owned by the requested address",
+            "id": 1152,
+            "implemented": true,
+            "kind": "function",
+            "modifiers": [],
+            "name": "_tokensOfOwner",
+            "nodeType": "FunctionDefinition",
+            "parameters": {
+              "id": 1142,
+              "nodeType": "ParameterList",
+              "parameters": [
+                {
+                  "constant": false,
+                  "id": 1141,
+                  "name": "owner",
+                  "nodeType": "VariableDeclaration",
+                  "scope": 1152,
+                  "src": "29225:13:1",
+                  "stateVariable": false,
+                  "storageLocation": "default",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_address",
+                    "typeString": "address"
+                  },
+                  "typeName": {
+                    "id": 1140,
+                    "name": "address",
+                    "nodeType": "ElementaryTypeName",
+                    "src": "29225:7:1",
+                    "stateMutability": "nonpayable",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_address",
+                      "typeString": "address"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                }
+              ],
+              "src": "29224:15:1"
+            },
+            "returnParameters": {
+              "id": 1146,
+              "nodeType": "ParameterList",
+              "parameters": [
+                {
+                  "constant": false,
+                  "id": 1145,
+                  "name": "",
+                  "nodeType": "VariableDeclaration",
+                  "scope": 1152,
+                  "src": "29263:17:1",
+                  "stateVariable": false,
+                  "storageLocation": "storage",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_array$_t_uint256_$dyn_storage_ptr",
+                    "typeString": "uint256[]"
+                  },
+                  "typeName": {
+                    "baseType": {
+                      "id": 1143,
+                      "name": "uint256",
+                      "nodeType": "ElementaryTypeName",
+                      "src": "29263:7:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_uint256",
+                        "typeString": "uint256"
+                      }
+                    },
+                    "id": 1144,
+                    "length": null,
+                    "nodeType": "ArrayTypeName",
+                    "src": "29263:9:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_array$_t_uint256_$dyn_storage_ptr",
+                      "typeString": "uint256[]"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                }
+              ],
+              "src": "29262:19:1"
+            },
+            "scope": 1302,
+            "src": "29201:124:1",
+            "stateMutability": "view",
+            "superFunction": null,
+            "visibility": "internal"
+          },
+          {
+            "body": {
+              "id": 1175,
+              "nodeType": "Block",
+              "src": "29693:109:1",
+              "statements": [
+                {
+                  "expression": {
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+                    "id": 1166,
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+                    "isLValue": false,
+                    "isPure": false,
+                    "lValueRequested": false,
+                    "leftHandSide": {
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+                      "baseExpression": {
+                        "argumentTypes": null,
+                        "id": 1159,
+                        "name": "_ownedTokensIndex",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 985,
+                        "src": "29703:17:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_mapping$_t_uint256_$_t_uint256_$",
+                          "typeString": "mapping(uint256 => uint256)"
+                        }
+                      },
+                      "id": 1161,
+                      "indexExpression": {
+                        "argumentTypes": null,
+                        "id": 1160,
+                        "name": "tokenId",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 1156,
+                        "src": "29721:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
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+                      "isLValue": true,
+                      "isPure": false,
+                      "lValueRequested": true,
+                      "nodeType": "IndexAccess",
+                      "src": "29703:26:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_uint256",
+                        "typeString": "uint256"
+                      }
+                    },
+                    "nodeType": "Assignment",
+                    "operator": "=",
+                    "rightHandSide": {
+                      "argumentTypes": null,
+                      "expression": {
+                        "argumentTypes": null,
+                        "baseExpression": {
+                          "argumentTypes": null,
+                          "id": 1162,
+                          "name": "_ownedTokens",
+                          "nodeType": "Identifier",
+                          "overloadedDeclarations": [],
+                          "referencedDeclaration": 981,
+                          "src": "29732:12:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_mapping$_t_address_$_t_array$_t_uint256_$dyn_storage_$",
+                            "typeString": "mapping(address => uint256[] storage ref)"
+                          }
+                        },
+                        "id": 1164,
+                        "indexExpression": {
+                          "argumentTypes": null,
+                          "id": 1163,
+                          "name": "to",
+                          "nodeType": "Identifier",
+                          "overloadedDeclarations": [],
+                          "referencedDeclaration": 1154,
+                          "src": "29745:2:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_address",
+                            "typeString": "address"
+                          }
+                        },
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+                              "typeDescriptions": {
+                                "typeIdentifier": "t_mapping$_t_address_$_t_array$_t_uint256_$dyn_storage_$",
+                                "typeString": "mapping(address => uint256[] storage ref)"
+                              }
+                            },
+                            "id": 1225,
+                            "indexExpression": {
+                              "argumentTypes": null,
+                              "id": 1224,
+                              "name": "from",
+                              "nodeType": "Identifier",
+                              "overloadedDeclarations": [],
+                              "referencedDeclaration": 1197,
+                              "src": "31332:4:1",
+                              "typeDescriptions": {
+                                "typeIdentifier": "t_address",
+                                "typeString": "address"
+                              }
+                            },
+                            "isConstant": false,
+                            "isLValue": true,
+                            "isPure": false,
+                            "lValueRequested": false,
+                            "nodeType": "IndexAccess",
+                            "src": "31319:18:1",
+                            "typeDescriptions": {
+                              "typeIdentifier": "t_array$_t_uint256_$dyn_storage",
+                              "typeString": "uint256[] storage ref"
+                            }
+                          },
+                          "id": 1227,
+                          "indexExpression": {
+                            "argumentTypes": null,
+                            "id": 1226,
+                            "name": "lastTokenIndex",
+                            "nodeType": "Identifier",
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+                            "referencedDeclaration": 1203,
+                            "src": "31338:14:1",
+                            "typeDescriptions": {
+                              "typeIdentifier": "t_uint256",
+                              "typeString": "uint256"
+                            }
+                          },
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+                          "isLValue": true,
+                          "isPure": false,
+                          "lValueRequested": false,
+                          "nodeType": "IndexAccess",
+                          "src": "31319:34:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_uint256",
+                            "typeString": "uint256"
+                          }
+                        },
+                        "nodeType": "VariableDeclarationStatement",
+                        "src": "31297:56:1"
+                      },
+                      {
+                        "expression": {
+                          "argumentTypes": null,
+                          "id": 1235,
+                          "isConstant": false,
+                          "isLValue": false,
+                          "isPure": false,
+                          "lValueRequested": false,
+                          "leftHandSide": {
+                            "argumentTypes": null,
+                            "baseExpression": {
+                              "argumentTypes": null,
+                              "baseExpression": {
+                                "argumentTypes": null,
+                                "id": 1229,
+                                "name": "_ownedTokens",
+                                "nodeType": "Identifier",
+                                "overloadedDeclarations": [],
+                                "referencedDeclaration": 981,
+                                "src": "31368:12:1",
+                                "typeDescriptions": {
+                                  "typeIdentifier": "t_mapping$_t_address_$_t_array$_t_uint256_$dyn_storage_$",
+                                  "typeString": "mapping(address => uint256[] storage ref)"
+                                }
+                              },
+                              "id": 1232,
+                              "indexExpression": {
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+                                "id": 1230,
+                                "name": "from",
+                                "nodeType": "Identifier",
+                                "overloadedDeclarations": [],
+                                "referencedDeclaration": 1197,
+                                "src": "31381:4:1",
+                                "typeDescriptions": {
+                                  "typeIdentifier": "t_address",
+                                  "typeString": "address"
+                                }
+                              },
+                              "isConstant": false,
+                              "isLValue": true,
+                              "isPure": false,
+                              "lValueRequested": false,
+                              "nodeType": "IndexAccess",
+                              "src": "31368:18:1",
+                              "typeDescriptions": {
+                                "typeIdentifier": "t_array$_t_uint256_$dyn_storage",
+                                "typeString": "uint256[] storage ref"
+                              }
+                            },
+                            "id": 1233,
+                            "indexExpression": {
+                              "argumentTypes": null,
+                              "id": 1231,
+                              "name": "tokenIndex",
+                              "nodeType": "Identifier",
+                              "overloadedDeclarations": [],
+                              "referencedDeclaration": 1213,
+                              "src": "31387:10:1",
+                              "typeDescriptions": {
+                                "typeIdentifier": "t_uint256",
+                                "typeString": "uint256"
+                              }
+                            },
+                            "isConstant": false,
+                            "isLValue": true,
+                            "isPure": false,
+                            "lValueRequested": true,
+                            "nodeType": "IndexAccess",
+                            "src": "31368:30:1",
+                            "typeDescriptions": {
+                              "typeIdentifier": "t_uint256",
+                              "typeString": "uint256"
+                            }
+                          },
+                          "nodeType": "Assignment",
+                          "operator": "=",
+                          "rightHandSide": {
+                            "argumentTypes": null,
+                            "id": 1234,
+                            "name": "lastTokenId",
+                            "nodeType": "Identifier",
+                            "overloadedDeclarations": [],
+                            "referencedDeclaration": 1222,
+                            "src": "31401:11:1",
+                            "typeDescriptions": {
+                              "typeIdentifier": "t_uint256",
+                              "typeString": "uint256"
+                            }
+                          },
+                          "src": "31368:44:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_uint256",
+                            "typeString": "uint256"
+                          }
+                        },
+                        "id": 1236,
+                        "nodeType": "ExpressionStatement",
+                        "src": "31368:44:1"
+                      },
+                      {
+                        "expression": {
+                          "argumentTypes": null,
+                          "id": 1241,
+                          "isConstant": false,
+                          "isLValue": false,
+                          "isPure": false,
+                          "lValueRequested": false,
+                          "leftHandSide": {
+                            "argumentTypes": null,
+                            "baseExpression": {
+                              "argumentTypes": null,
+                              "id": 1237,
+                              "name": "_ownedTokensIndex",
+                              "nodeType": "Identifier",
+                              "overloadedDeclarations": [],
+                              "referencedDeclaration": 985,
+                              "src": "31484:17:1",
+                              "typeDescriptions": {
+                                "typeIdentifier": "t_mapping$_t_uint256_$_t_uint256_$",
+                                "typeString": "mapping(uint256 => uint256)"
+                              }
+                            },
+                            "id": 1239,
+                            "indexExpression": {
+                              "argumentTypes": null,
+                              "id": 1238,
+                              "name": "lastTokenId",
+                              "nodeType": "Identifier",
+                              "overloadedDeclarations": [],
+                              "referencedDeclaration": 1222,
+                              "src": "31502:11:1",
+                              "typeDescriptions": {
+                                "typeIdentifier": "t_uint256",
+                                "typeString": "uint256"
+                              }
+                            },
+                            "isConstant": false,
+                            "isLValue": true,
+                            "isPure": false,
+                            "lValueRequested": true,
+                            "nodeType": "IndexAccess",
+                            "src": "31484:30:1",
+                            "typeDescriptions": {
+                              "typeIdentifier": "t_uint256",
+                              "typeString": "uint256"
+                            }
+                          },
+                          "nodeType": "Assignment",
+                          "operator": "=",
+                          "rightHandSide": {
+                            "argumentTypes": null,
+                            "id": 1240,
+                            "name": "tokenIndex",
+                            "nodeType": "Identifier",
+                            "overloadedDeclarations": [],
+                            "referencedDeclaration": 1213,
+                            "src": "31517:10:1",
+                            "typeDescriptions": {
+                              "typeIdentifier": "t_uint256",
+                              "typeString": "uint256"
+                            }
+                          },
+                          "src": "31484:43:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_uint256",
+                            "typeString": "uint256"
+                          }
+                        },
+                        "id": 1242,
+                        "nodeType": "ExpressionStatement",
+                        "src": "31484:43:1"
+                      }
+                    ]
+                  }
+                },
+                {
+                  "expression": {
+                    "argumentTypes": null,
+                    "id": 1249,
+                    "isConstant": false,
+                    "isLValue": false,
+                    "isPure": false,
+                    "lValueRequested": false,
+                    "nodeType": "UnaryOperation",
+                    "operator": "--",
+                    "prefix": false,
+                    "src": "31658:27:1",
+                    "subExpression": {
+                      "argumentTypes": null,
+                      "expression": {
+                        "argumentTypes": null,
+                        "baseExpression": {
+                          "argumentTypes": null,
+                          "id": 1245,
+                          "name": "_ownedTokens",
+                          "nodeType": "Identifier",
+                          "overloadedDeclarations": [],
+                          "referencedDeclaration": 981,
+                          "src": "31658:12:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_mapping$_t_address_$_t_array$_t_uint256_$dyn_storage_$",
+                            "typeString": "mapping(address => uint256[] storage ref)"
+                          }
+                        },
+                        "id": 1247,
+                        "indexExpression": {
+                          "argumentTypes": null,
+                          "id": 1246,
+                          "name": "from",
+                          "nodeType": "Identifier",
+                          "overloadedDeclarations": [],
+                          "referencedDeclaration": 1197,
+                          "src": "31671:4:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_address",
+                            "typeString": "address"
+                          }
+                        },
+                        "isConstant": false,
+                        "isLValue": true,
+                        "isPure": false,
+                        "lValueRequested": false,
+                        "nodeType": "IndexAccess",
+                        "src": "31658:18:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_array$_t_uint256_$dyn_storage",
+                          "typeString": "uint256[] storage ref"
+                        }
+                      },
+                      "id": 1248,
+                      "isConstant": false,
+                      "isLValue": true,
+                      "isPure": false,
+                      "lValueRequested": true,
+                      "memberName": "length",
+                      "nodeType": "MemberAccess",
+                      "referencedDeclaration": null,
+                      "src": "31658:25:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_uint256",
+                        "typeString": "uint256"
+                      }
+                    },
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_uint256",
+                      "typeString": "uint256"
+                    }
+                  },
+                  "id": 1250,
+                  "nodeType": "ExpressionStatement",
+                  "src": "31658:27:1"
+                }
+              ]
+            },
+            "documentation": "@dev Private function to remove a token from this extension's ownership-tracking data structures. Note that\nwhile the token is not assigned a new owner, the _ownedTokensIndex mapping is _not_ updated: this allows for\ngas optimizations e.g. when performing a transfer operation (avoiding double writes).\nThis has O(1) time complexity, but alters the order of the _ownedTokens array.\n@param from address representing the previous owner of the given token ID\n@param tokenId uint256 ID of the token to be removed from the tokens list of the given address",
+            "id": 1252,
+            "implemented": true,
+            "kind": "function",
+            "modifiers": [],
+            "name": "_removeTokenFromOwnerEnumeration",
+            "nodeType": "FunctionDefinition",
+            "parameters": {
+              "id": 1200,
+              "nodeType": "ParameterList",
+              "parameters": [
+                {
+                  "constant": false,
+                  "id": 1197,
+                  "name": "from",
+                  "nodeType": "VariableDeclaration",
+                  "scope": 1252,
+                  "src": "30815:12:1",
+                  "stateVariable": false,
+                  "storageLocation": "default",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_address",
+                    "typeString": "address"
+                  },
+                  "typeName": {
+                    "id": 1196,
+                    "name": "address",
+                    "nodeType": "ElementaryTypeName",
+                    "src": "30815:7:1",
+                    "stateMutability": "nonpayable",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_address",
+                      "typeString": "address"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                },
+                {
+                  "constant": false,
+                  "id": 1199,
+                  "name": "tokenId",
+                  "nodeType": "VariableDeclaration",
+                  "scope": 1252,
+                  "src": "30829:15:1",
+                  "stateVariable": false,
+                  "storageLocation": "default",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_uint256",
+                    "typeString": "uint256"
+                  },
+                  "typeName": {
+                    "id": 1198,
+                    "name": "uint256",
+                    "nodeType": "ElementaryTypeName",
+                    "src": "30829:7:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_uint256",
+                      "typeString": "uint256"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                }
+              ],
+              "src": "30814:31:1"
+            },
+            "returnParameters": {
+              "id": 1201,
+              "nodeType": "ParameterList",
+              "parameters": [],
+              "src": "30854:0:1"
+            },
+            "scope": 1302,
+            "src": "30773:1128:1",
+            "stateMutability": "nonpayable",
+            "superFunction": null,
+            "visibility": "private"
+          },
+          {
+            "body": {
+              "id": 1300,
+              "nodeType": "Block",
+              "src": "32260:993:1",
+              "statements": [
+                {
+                  "assignments": [
+                    1258
+                  ],
+                  "declarations": [
+                    {
+                      "constant": false,
+                      "id": 1258,
+                      "name": "lastTokenIndex",
+                      "nodeType": "VariableDeclaration",
+                      "scope": 1300,
+                      "src": "32438:22:1",
+                      "stateVariable": false,
+                      "storageLocation": "default",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_uint256",
+                        "typeString": "uint256"
+                      },
+                      "typeName": {
+                        "id": 1257,
+                        "name": "uint256",
+                        "nodeType": "ElementaryTypeName",
+                        "src": "32438:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      },
+                      "value": null,
+                      "visibility": "internal"
+                    }
+                  ],
+                  "id": 1264,
+                  "initialValue": {
+                    "argumentTypes": null,
+                    "arguments": [
+                      {
+                        "argumentTypes": null,
+                        "hexValue": "31",
+                        "id": 1262,
+                        "isConstant": false,
+                        "isLValue": false,
+                        "isPure": true,
+                        "kind": "number",
+                        "lValueRequested": false,
+                        "nodeType": "Literal",
+                        "src": "32485:1:1",
+                        "subdenomination": null,
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_rational_1_by_1",
+                          "typeString": "int_const 1"
+                        },
+                        "value": "1"
+                      }
+                    ],
+                    "expression": {
+                      "argumentTypes": [
+                        {
+                          "typeIdentifier": "t_rational_1_by_1",
+                          "typeString": "int_const 1"
+                        }
+                      ],
+                      "expression": {
+                        "argumentTypes": null,
+                        "expression": {
+                          "argumentTypes": null,
+                          "id": 1259,
+                          "name": "_allTokens",
+                          "nodeType": "Identifier",
+                          "overloadedDeclarations": [],
+                          "referencedDeclaration": 988,
+                          "src": "32463:10:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_array$_t_uint256_$dyn_storage",
+                            "typeString": "uint256[] storage ref"
+                          }
+                        },
+                        "id": 1260,
+                        "isConstant": false,
+                        "isLValue": true,
+                        "isPure": false,
+                        "lValueRequested": false,
+                        "memberName": "length",
+                        "nodeType": "MemberAccess",
+                        "referencedDeclaration": null,
+                        "src": "32463:17:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      },
+                      "id": 1261,
+                      "isConstant": false,
+                      "isLValue": false,
+                      "isPure": false,
+                      "lValueRequested": false,
+                      "memberName": "sub",
+                      "nodeType": "MemberAccess",
+                      "referencedDeclaration": 190,
+                      "src": "32463:21:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_function_internal_pure$_t_uint256_$_t_uint256_$returns$_t_uint256_$bound_to$_t_uint256_$",
+                        "typeString": "function (uint256,uint256) pure returns (uint256)"
+                      }
+                    },
+                    "id": 1263,
+                    "isConstant": false,
+                    "isLValue": false,
+                    "isPure": false,
+                    "kind": "functionCall",
+                    "lValueRequested": false,
+                    "names": [],
+                    "nodeType": "FunctionCall",
+                    "src": "32463:24:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_uint256",
+                      "typeString": "uint256"
+                    }
+                  },
+                  "nodeType": "VariableDeclarationStatement",
+                  "src": "32438:49:1"
+                },
+                {
+                  "assignments": [
+                    1266
+                  ],
+                  "declarations": [
+                    {
+                      "constant": false,
+                      "id": 1266,
+                      "name": "tokenIndex",
+                      "nodeType": "VariableDeclaration",
+                      "scope": 1300,
+                      "src": "32497:18:1",
+                      "stateVariable": false,
+                      "storageLocation": "default",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_uint256",
+                        "typeString": "uint256"
+                      },
+                      "typeName": {
+                        "id": 1265,
+                        "name": "uint256",
+                        "nodeType": "ElementaryTypeName",
+                        "src": "32497:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      },
+                      "value": null,
+                      "visibility": "internal"
+                    }
+                  ],
+                  "id": 1270,
+                  "initialValue": {
+                    "argumentTypes": null,
+                    "baseExpression": {
+                      "argumentTypes": null,
+                      "id": 1267,
+                      "name": "_allTokensIndex",
+                      "nodeType": "Identifier",
+                      "overloadedDeclarations": [],
+                      "referencedDeclaration": 992,
+                      "src": "32518:15:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_mapping$_t_uint256_$_t_uint256_$",
+                        "typeString": "mapping(uint256 => uint256)"
+                      }
+                    },
+                    "id": 1269,
+                    "indexExpression": {
+                      "argumentTypes": null,
+                      "id": 1268,
+                      "name": "tokenId",
+                      "nodeType": "Identifier",
+                      "overloadedDeclarations": [],
+                      "referencedDeclaration": 1254,
+                      "src": "32534:7:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_uint256",
+                        "typeString": "uint256"
+                      }
+                    },
+                    "isConstant": false,
+                    "isLValue": true,
+                    "isPure": false,
+                    "lValueRequested": false,
+                    "nodeType": "IndexAccess",
+                    "src": "32518:24:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_uint256",
+                      "typeString": "uint256"
+                    }
+                  },
+                  "nodeType": "VariableDeclarationStatement",
+                  "src": "32497:45:1"
+                },
+                {
+                  "assignments": [
+                    1272
+                  ],
+                  "declarations": [
+                    {
+                      "constant": false,
+                      "id": 1272,
+                      "name": "lastTokenId",
+                      "nodeType": "VariableDeclaration",
+                      "scope": 1300,
+                      "src": "32864:19:1",
+                      "stateVariable": false,
+                      "storageLocation": "default",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_uint256",
+                        "typeString": "uint256"
+                      },
+                      "typeName": {
+                        "id": 1271,
+                        "name": "uint256",
+                        "nodeType": "ElementaryTypeName",
+                        "src": "32864:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      },
+                      "value": null,
+                      "visibility": "internal"
+                    }
+                  ],
+                  "id": 1276,
+                  "initialValue": {
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+                    "baseExpression": {
+                      "argumentTypes": null,
+                      "id": 1273,
+                      "name": "_allTokens",
+                      "nodeType": "Identifier",
+                      "overloadedDeclarations": [],
+                      "referencedDeclaration": 988,
+                      "src": "32886:10:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_array$_t_uint256_$dyn_storage",
+                        "typeString": "uint256[] storage ref"
+                      }
+                    },
+                    "id": 1275,
+                    "indexExpression": {
+                      "argumentTypes": null,
+                      "id": 1274,
+                      "name": "lastTokenIndex",
+                      "nodeType": "Identifier",
+                      "overloadedDeclarations": [],
+                      "referencedDeclaration": 1258,
+                      "src": "32897:14:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_uint256",
+                        "typeString": "uint256"
+                      }
+                    },
+                    "isConstant": false,
+                    "isLValue": true,
+                    "isPure": false,
+                    "lValueRequested": false,
+                    "nodeType": "IndexAccess",
+                    "src": "32886:26:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_uint256",
+                      "typeString": "uint256"
+                    }
+                  },
+                  "nodeType": "VariableDeclarationStatement",
+                  "src": "32864:48:1"
+                },
+                {
+                  "expression": {
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+                    "id": 1281,
+                    "isConstant": false,
+                    "isLValue": false,
+                    "isPure": false,
+                    "lValueRequested": false,
+                    "leftHandSide": {
+                      "argumentTypes": null,
+                      "baseExpression": {
+                        "argumentTypes": null,
+                        "id": 1277,
+                        "name": "_allTokens",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 988,
+                        "src": "32923:10:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_array$_t_uint256_$dyn_storage",
+                          "typeString": "uint256[] storage ref"
+                        }
+                      },
+                      "id": 1279,
+                      "indexExpression": {
+                        "argumentTypes": null,
+                        "id": 1278,
+                        "name": "tokenIndex",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 1266,
+                        "src": "32934:10:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      },
+                      "isConstant": false,
+                      "isLValue": true,
+                      "isPure": false,
+                      "lValueRequested": true,
+                      "nodeType": "IndexAccess",
+                      "src": "32923:22:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_uint256",
+                        "typeString": "uint256"
+                      }
+                    },
+                    "nodeType": "Assignment",
+                    "operator": "=",
+                    "rightHandSide": {
+                      "argumentTypes": null,
+                      "id": 1280,
+                      "name": "lastTokenId",
+                      "nodeType": "Identifier",
+                      "overloadedDeclarations": [],
+                      "referencedDeclaration": 1272,
+                      "src": "32948:11:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_uint256",
+                        "typeString": "uint256"
+                      }
+                    },
+                    "src": "32923:36:1",
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+              "name": "IERC165",
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+                "typeString": "contract IERC165"
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+                          "typeString": "bytes memory"
+                        }
+                      }
+                    ],
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+                          "typeString": "address payable"
+                        },
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+                          "typeString": "address"
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+                            }
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+                          "name": "IERC721Receiver",
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+                          "src": "23593:15:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_type$_t_contract$_IERC721Receiver_$139_$",
+                            "typeString": "type(contract IERC721Receiver)"
+                          }
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+                          "typeDescriptions": {
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+                            "typeString": "bytes4"
+                          }
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+              ]
+            },
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+                        "src": "23940:15:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_mapping$_t_uint256_$_t_address_$",
+                          "typeString": "mapping(uint256 => address)"
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+                              "src": "23994:15:1",
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+                                "kind": "number",
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+                                "nodeType": "Literal",
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+                                  "typeString": "int_const 0"
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+                            ],
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+                              "isConstant": false,
+                              "isLValue": false,
+                              "isPure": true,
+                              "lValueRequested": false,
+                              "nodeType": "ElementaryTypeNameExpression",
+                              "src": "24021:7:1",
+                              "typeDescriptions": {
+                                "typeIdentifier": "t_type$_t_address_$",
+                                "typeString": "type(address)"
+                              },
+                              "typeName": "address"
+                            },
+                            "id": 937,
+                            "isConstant": false,
+                            "isLValue": false,
+                            "isPure": true,
+                            "kind": "typeConversion",
+                            "lValueRequested": false,
+                            "names": [],
+                            "nodeType": "FunctionCall",
+                            "src": "24021:10:1",
+                            "typeDescriptions": {
+                              "typeIdentifier": "t_address_payable",
+                              "typeString": "address payable"
+                            }
+                          },
+                          "src": "23994:37:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_address",
+                            "typeString": "address"
+                          }
+                        },
+                        "id": 939,
+                        "nodeType": "ExpressionStatement",
+                        "src": "23994:37:1"
+                      }
+                    ]
+                  }
+                }
+              ]
+            },
+            "documentation": "@dev Private function to clear current approval of a given token ID.\n@param tokenId uint256 ID of the token to be transferred",
+            "id": 943,
+            "implemented": true,
+            "kind": "function",
+            "modifiers": [],
+            "name": "_clearApproval",
+            "nodeType": "FunctionDefinition",
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+              "nodeType": "ParameterList",
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+                  "stateVariable": false,
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+                    "name": "uint256",
+                    "nodeType": "ElementaryTypeName",
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+                      "typeString": "uint256"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                }
+              ],
+              "src": "23900:17:1"
+            },
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+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      }
+                    ],
+                    "expression": {
+                      "argumentTypes": [
+                        {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      ],
+                      "id": 1134,
+                      "name": "_removeTokenFromAllTokensEnumeration",
+                      "nodeType": "Identifier",
+                      "overloadedDeclarations": [],
+                      "referencedDeclaration": 1301,
+                      "src": "28944:36:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_function_internal_nonpayable$_t_uint256_$returns$__$",
+                        "typeString": "function (uint256)"
+                      }
+                    },
+                    "id": 1136,
+                    "isConstant": false,
+                    "isLValue": false,
+                    "isPure": false,
+                    "kind": "functionCall",
+                    "lValueRequested": false,
+                    "names": [],
+                    "nodeType": "FunctionCall",
+                    "src": "28944:45:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_tuple$__$",
+                      "typeString": "tuple()"
+                    }
+                  },
+                  "id": 1137,
+                  "nodeType": "ExpressionStatement",
+                  "src": "28944:45:1"
+                }
+              ]
+            },
+            "documentation": "@dev Internal function to burn a specific token.\nReverts if the token does not exist.\nDeprecated, use _burn(uint256) instead.\n@param owner owner of the token to burn\n@param tokenId uint256 ID of the token being burned",
+            "id": 1139,
+            "implemented": true,
+            "kind": "function",
+            "modifiers": [],
+            "name": "_burn",
+            "nodeType": "FunctionDefinition",
+            "parameters": {
+              "id": 1114,
+              "nodeType": "ParameterList",
+              "parameters": [
+                {
+                  "constant": false,
+                  "id": 1111,
+                  "name": "owner",
+                  "nodeType": "VariableDeclaration",
+                  "scope": 1139,
+                  "src": "28647:13:1",
+                  "stateVariable": false,
+                  "storageLocation": "default",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_address",
+                    "typeString": "address"
+                  },
+                  "typeName": {
+                    "id": 1110,
+                    "name": "address",
+                    "nodeType": "ElementaryTypeName",
+                    "src": "28647:7:1",
+                    "stateMutability": "nonpayable",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_address",
+                      "typeString": "address"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                },
+                {
+                  "constant": false,
+                  "id": 1113,
+                  "name": "tokenId",
+                  "nodeType": "VariableDeclaration",
+                  "scope": 1139,
+                  "src": "28662:15:1",
+                  "stateVariable": false,
+                  "storageLocation": "default",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_uint256",
+                    "typeString": "uint256"
+                  },
+                  "typeName": {
+                    "id": 1112,
+                    "name": "uint256",
+                    "nodeType": "ElementaryTypeName",
+                    "src": "28662:7:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_uint256",
+                      "typeString": "uint256"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                }
+              ],
+              "src": "28646:32:1"
+            },
+            "returnParameters": {
+              "id": 1115,
+              "nodeType": "ParameterList",
+              "parameters": [],
+              "src": "28688:0:1"
+            },
+            "scope": 1302,
+            "src": "28632:364:1",
+            "stateMutability": "nonpayable",
+            "superFunction": 811,
+            "visibility": "internal"
+          },
+          {
+            "body": {
+              "id": 1151,
+              "nodeType": "Block",
+              "src": "29282:43:1",
+              "statements": [
+                {
+                  "expression": {
+                    "argumentTypes": null,
+                    "baseExpression": {
+                      "argumentTypes": null,
+                      "id": 1147,
+                      "name": "_ownedTokens",
+                      "nodeType": "Identifier",
+                      "overloadedDeclarations": [],
+                      "referencedDeclaration": 981,
+                      "src": "29299:12:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_mapping$_t_address_$_t_array$_t_uint256_$dyn_storage_$",
+                        "typeString": "mapping(address => uint256[] storage ref)"
+                      }
+                    },
+                    "id": 1149,
+                    "indexExpression": {
+                      "argumentTypes": null,
+                      "id": 1148,
+                      "name": "owner",
+                      "nodeType": "Identifier",
+                      "overloadedDeclarations": [],
+                      "referencedDeclaration": 1141,
+                      "src": "29312:5:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_address",
+                        "typeString": "address"
+                      }
+                    },
+                    "isConstant": false,
+                    "isLValue": true,
+                    "isPure": false,
+                    "lValueRequested": false,
+                    "nodeType": "IndexAccess",
+                    "src": "29299:19:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_array$_t_uint256_$dyn_storage",
+                      "typeString": "uint256[] storage ref"
+                    }
+                  },
+                  "functionReturnParameters": 1146,
+                  "id": 1150,
+                  "nodeType": "Return",
+                  "src": "29292:26:1"
+                }
+              ]
+            },
+            "documentation": "@dev Gets the list of token IDs of the requested owner.\n@param owner address owning the tokens\n@return uint256[] List of token IDs owned by the requested address",
+            "id": 1152,
+            "implemented": true,
+            "kind": "function",
+            "modifiers": [],
+            "name": "_tokensOfOwner",
+            "nodeType": "FunctionDefinition",
+            "parameters": {
+              "id": 1142,
+              "nodeType": "ParameterList",
+              "parameters": [
+                {
+                  "constant": false,
+                  "id": 1141,
+                  "name": "owner",
+                  "nodeType": "VariableDeclaration",
+                  "scope": 1152,
+                  "src": "29225:13:1",
+                  "stateVariable": false,
+                  "storageLocation": "default",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_address",
+                    "typeString": "address"
+                  },
+                  "typeName": {
+                    "id": 1140,
+                    "name": "address",
+                    "nodeType": "ElementaryTypeName",
+                    "src": "29225:7:1",
+                    "stateMutability": "nonpayable",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_address",
+                      "typeString": "address"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                }
+              ],
+              "src": "29224:15:1"
+            },
+            "returnParameters": {
+              "id": 1146,
+              "nodeType": "ParameterList",
+              "parameters": [
+                {
+                  "constant": false,
+                  "id": 1145,
+                  "name": "",
+                  "nodeType": "VariableDeclaration",
+                  "scope": 1152,
+                  "src": "29263:17:1",
+                  "stateVariable": false,
+                  "storageLocation": "storage",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_array$_t_uint256_$dyn_storage_ptr",
+                    "typeString": "uint256[]"
+                  },
+                  "typeName": {
+                    "baseType": {
+                      "id": 1143,
+                      "name": "uint256",
+                      "nodeType": "ElementaryTypeName",
+                      "src": "29263:7:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_uint256",
+                        "typeString": "uint256"
+                      }
+                    },
+                    "id": 1144,
+                    "length": null,
+                    "nodeType": "ArrayTypeName",
+                    "src": "29263:9:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_array$_t_uint256_$dyn_storage_ptr",
+                      "typeString": "uint256[]"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                }
+              ],
+              "src": "29262:19:1"
+            },
+            "scope": 1302,
+            "src": "29201:124:1",
+            "stateMutability": "view",
+            "superFunction": null,
+            "visibility": "internal"
+          },
+          {
+            "body": {
+              "id": 1175,
+              "nodeType": "Block",
+              "src": "29693:109:1",
+              "statements": [
+                {
+                  "expression": {
+                    "argumentTypes": null,
+                    "id": 1166,
+                    "isConstant": false,
+                    "isLValue": false,
+                    "isPure": false,
+                    "lValueRequested": false,
+                    "leftHandSide": {
+                      "argumentTypes": null,
+                      "baseExpression": {
+                        "argumentTypes": null,
+                        "id": 1159,
+                        "name": "_ownedTokensIndex",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 985,
+                        "src": "29703:17:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_mapping$_t_uint256_$_t_uint256_$",
+                          "typeString": "mapping(uint256 => uint256)"
+                        }
+                      },
+                      "id": 1161,
+                      "indexExpression": {
+                        "argumentTypes": null,
+                        "id": 1160,
+                        "name": "tokenId",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 1156,
+                        "src": "29721:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      },
+                      "isConstant": false,
+                      "isLValue": true,
+                      "isPure": false,
+                      "lValueRequested": true,
+                      "nodeType": "IndexAccess",
+                      "src": "29703:26:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_uint256",
+                        "typeString": "uint256"
+                      }
+                    },
+                    "nodeType": "Assignment",
+                    "operator": "=",
+                    "rightHandSide": {
+                      "argumentTypes": null,
+                      "expression": {
+                        "argumentTypes": null,
+                        "baseExpression": {
+                          "argumentTypes": null,
+                          "id": 1162,
+                          "name": "_ownedTokens",
+                          "nodeType": "Identifier",
+                          "overloadedDeclarations": [],
+                          "referencedDeclaration": 981,
+                          "src": "29732:12:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_mapping$_t_address_$_t_array$_t_uint256_$dyn_storage_$",
+                            "typeString": "mapping(address => uint256[] storage ref)"
+                          }
+                        },
+                        "id": 1164,
+                        "indexExpression": {
+                          "argumentTypes": null,
+                          "id": 1163,
+                          "name": "to",
+                          "nodeType": "Identifier",
+                          "overloadedDeclarations": [],
+                          "referencedDeclaration": 1154,
+                          "src": "29745:2:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_address",
+                            "typeString": "address"
+                          }
+                        },
+                        "isConstant": false,
+                        "isLValue": true,
+                        "isPure": false,
+                        "lValueRequested": false,
+                        "nodeType": "IndexAccess",
+                        "src": "29732:16:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_array$_t_uint256_$dyn_storage",
+                          "typeString": "uint256[] storage ref"
+                        }
+                      },
+                      "id": 1165,
+                      "isConstant": false,
+                      "isLValue": true,
+                      "isPure": false,
+                      "lValueRequested": false,
+                      "memberName": "length",
+                      "nodeType": "MemberAccess",
+                      "referencedDeclaration": null,
+                      "src": "29732:23:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_uint256",
+                        "typeString": "uint256"
+                      }
+                    },
+                    "src": "29703:52:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_uint256",
+                      "typeString": "uint256"
+                    }
+                  },
+                  "id": 1167,
+                  "nodeType": "ExpressionStatement",
+                  "src": "29703:52:1"
+                },
+                {
+                  "expression": {
+                    "argumentTypes": null,
+                    "arguments": [
+                      {
+                        "argumentTypes": null,
+                        "id": 1172,
+                        "name": "tokenId",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 1156,
+                        "src": "29787:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      }
+                    ],
+                    "expression": {
+                      "argumentTypes": [
+                        {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      ],
+                      "expression": {
+                        "argumentTypes": null,
+                        "baseExpression": {
+                          "argumentTypes": null,
+                          "id": 1168,
+                          "name": "_ownedTokens",
+                          "nodeType": "Identifier",
+                          "overloadedDeclarations": [],
+                          "referencedDeclaration": 981,
+                          "src": "29765:12:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_mapping$_t_address_$_t_array$_t_uint256_$dyn_storage_$",
+                            "typeString": "mapping(address => uint256[] storage ref)"
+                          }
+                        },
+                        "id": 1170,
+                        "indexExpression": {
+                          "argumentTypes": null,
+                          "id": 1169,
+                          "name": "to",
+                          "nodeType": "Identifier",
+                          "overloadedDeclarations": [],
+                          "referencedDeclaration": 1154,
+                          "src": "29778:2:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_address",
+                            "typeString": "address"
+                          }
+                        },
+                        "isConstant": false,
+                        "isLValue": true,
+                        "isPure": false,
+                        "lValueRequested": false,
+                        "nodeType": "IndexAccess",
+                        "src": "29765:16:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_array$_t_uint256_$dyn_storage",
+                          "typeString": "uint256[] storage ref"
+                        }
+                      },
+                      "id": 1171,
+                      "isConstant": false,
+                      "isLValue": false,
+                      "isPure": false,
+                      "lValueRequested": false,
+                      "memberName": "push",
+                      "nodeType": "MemberAccess",
+                      "referencedDeclaration": null,
+                      "src": "29765:21:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_function_arraypush_nonpayable$_t_uint256_$returns$_t_uint256_$",
+                        "typeString": "function (uint256) returns (uint256)"
+                      }
+                    },
+                    "id": 1173,
+                    "isConstant": false,
+                    "isLValue": false,
+                    "isPure": false,
+                    "kind": "functionCall",
+                    "lValueRequested": false,
+                    "names": [],
+                    "nodeType": "FunctionCall",
+                    "src": "29765:30:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_uint256",
+                      "typeString": "uint256"
+                    }
+                  },
+                  "id": 1174,
+                  "nodeType": "ExpressionStatement",
+                  "src": "29765:30:1"
+                }
+              ]
+            },
+            "documentation": "@dev Private function to add a token to this extension's ownership-tracking data structures.\n@param to address representing the new owner of the given token ID\n@param tokenId uint256 ID of the token to be added to the tokens list of the given address",
+            "id": 1176,
+            "implemented": true,
+            "kind": "function",
+            "modifiers": [],
+            "name": "_addTokenToOwnerEnumeration",
+            "nodeType": "FunctionDefinition",
+            "parameters": {
+              "id": 1157,
+              "nodeType": "ParameterList",
+              "parameters": [
+                {
+                  "constant": false,
+                  "id": 1154,
+                  "name": "to",
+                  "nodeType": "VariableDeclaration",
+                  "scope": 1176,
+                  "src": "29656:10:1",
+                  "stateVariable": false,
+                  "storageLocation": "default",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_address",
+                    "typeString": "address"
+                  },
+                  "typeName": {
+                    "id": 1153,
+                    "name": "address",
+                    "nodeType": "ElementaryTypeName",
+                    "src": "29656:7:1",
+                    "stateMutability": "nonpayable",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_address",
+                      "typeString": "address"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                },
+                {
+                  "constant": false,
+                  "id": 1156,
+                  "name": "tokenId",
+                  "nodeType": "VariableDeclaration",
+                  "scope": 1176,
+                  "src": "29668:15:1",
+                  "stateVariable": false,
+                  "storageLocation": "default",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_uint256",
+                    "typeString": "uint256"
+                  },
+                  "typeName": {
+                    "id": 1155,
+                    "name": "uint256",
+                    "nodeType": "ElementaryTypeName",
+                    "src": "29668:7:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_uint256",
+                      "typeString": "uint256"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                }
+              ],
+              "src": "29655:29:1"
+            },
+            "returnParameters": {
+              "id": 1158,
+              "nodeType": "ParameterList",
+              "parameters": [],
+              "src": "29693:0:1"
+            },
+            "scope": 1302,
+            "src": "29619:183:1",
+            "stateMutability": "nonpayable",
+            "superFunction": null,
+            "visibility": "private"
+          },
+          {
+            "body": {
+              "id": 1194,
+              "nodeType": "Block",
+              "src": "30063:95:1",
+              "statements": [
+                {
+                  "expression": {
+                    "argumentTypes": null,
+                    "id": 1186,
+                    "isConstant": false,
+                    "isLValue": false,
+                    "isPure": false,
+                    "lValueRequested": false,
+                    "leftHandSide": {
+                      "argumentTypes": null,
+                      "baseExpression": {
+                        "argumentTypes": null,
+                        "id": 1181,
+                        "name": "_allTokensIndex",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 992,
+                        "src": "30073:15:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_mapping$_t_uint256_$_t_uint256_$",
+                          "typeString": "mapping(uint256 => uint256)"
+                        }
+                      },
+                      "id": 1183,
+                      "indexExpression": {
+                        "argumentTypes": null,
+                        "id": 1182,
+                        "name": "tokenId",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 1178,
+                        "src": "30089:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      },
+                      "isConstant": false,
+                      "isLValue": true,
+                      "isPure": false,
+                      "lValueRequested": true,
+                      "nodeType": "IndexAccess",
+                      "src": "30073:24:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_uint256",
+                        "typeString": "uint256"
+                      }
+                    },
+                    "nodeType": "Assignment",
+                    "operator": "=",
+                    "rightHandSide": {
+                      "argumentTypes": null,
+                      "expression": {
+                        "argumentTypes": null,
+                        "id": 1184,
+                        "name": "_allTokens",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 988,
+                        "src": "30100:10:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_array$_t_uint256_$dyn_storage",
+                          "typeString": "uint256[] storage ref"
+                        }
+                      },
+                      "id": 1185,
+                      "isConstant": false,
+                      "isLValue": true,
+                      "isPure": false,
+                      "lValueRequested": false,
+                      "memberName": "length",
+                      "nodeType": "MemberAccess",
+                      "referencedDeclaration": null,
+                      "src": "30100:17:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_uint256",
+                        "typeString": "uint256"
+                      }
+                    },
+                    "src": "30073:44:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_uint256",
+                      "typeString": "uint256"
+                    }
+                  },
+                  "id": 1187,
+                  "nodeType": "ExpressionStatement",
+                  "src": "30073:44:1"
+                },
+                {
+                  "expression": {
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+                    "arguments": [
+                      {
+                        "argumentTypes": null,
+                        "id": 1191,
+                        "name": "tokenId",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 1178,
+                        "src": "30143:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      }
+                    ],
+                    "expression": {
+                      "argumentTypes": [
+                        {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      ],
+                      "expression": {
+                        "argumentTypes": null,
+                        "id": 1188,
+                        "name": "_allTokens",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 988,
+                        "src": "30127:10:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_array$_t_uint256_$dyn_storage",
+                          "typeString": "uint256[] storage ref"
+                        }
+                      },
+                      "id": 1190,
+                      "isConstant": false,
+                      "isLValue": false,
+                      "isPure": false,
+                      "lValueRequested": false,
+                      "memberName": "push",
+                      "nodeType": "MemberAccess",
+                      "referencedDeclaration": null,
+                      "src": "30127:15:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_function_arraypush_nonpayable$_t_uint256_$returns$_t_uint256_$",
+                        "typeString": "function (uint256) returns (uint256)"
+                      }
+                    },
+                    "id": 1192,
+                    "isConstant": false,
+                    "isLValue": false,
+                    "isPure": false,
+                    "kind": "functionCall",
+                    "lValueRequested": false,
+                    "names": [],
+                    "nodeType": "FunctionCall",
+                    "src": "30127:24:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_uint256",
+                      "typeString": "uint256"
+                    }
+                  },
+                  "id": 1193,
+                  "nodeType": "ExpressionStatement",
+                  "src": "30127:24:1"
+                }
+              ]
+            },
+            "documentation": "@dev Private function to add a token to this extension's token tracking data structures.\n@param tokenId uint256 ID of the token to be added to the tokens list",
+            "id": 1195,
+            "implemented": true,
+            "kind": "function",
+            "modifiers": [],
+            "name": "_addTokenToAllTokensEnumeration",
+            "nodeType": "FunctionDefinition",
+            "parameters": {
+              "id": 1179,
+              "nodeType": "ParameterList",
+              "parameters": [
+                {
+                  "constant": false,
+                  "id": 1178,
+                  "name": "tokenId",
+                  "nodeType": "VariableDeclaration",
+                  "scope": 1195,
+                  "src": "30038:15:1",
+                  "stateVariable": false,
+                  "storageLocation": "default",
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+                        },
+                        "value": "1"
+                      }
+                    ],
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+                            "src": "31060:12:1",
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+                              "typeIdentifier": "t_mapping$_t_address_$_t_array$_t_uint256_$dyn_storage_$",
+                              "typeString": "mapping(address => uint256[] storage ref)"
+                            }
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+                              "typeIdentifier": "t_address",
+                              "typeString": "address"
+                            }
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+                        "typeString": "function (uint256,uint256) pure returns (uint256)"
+                      }
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+                    "src": "31060:32:1",
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+                      "typeIdentifier": "t_uint256",
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+                    }
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+                },
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+                        "typeIdentifier": "t_uint256",
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+                      },
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+                        "name": "uint256",
+                        "nodeType": "ElementaryTypeName",
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+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
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+                        "typeIdentifier": "t_mapping$_t_uint256_$_t_uint256_$",
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+                      }
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+                        "typeString": "uint256"
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+                      "typeString": "uint256"
+                    }
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+                },
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+                      "src": "31253:10:1",
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+                        "typeIdentifier": "t_uint256",
+                        "typeString": "uint256"
+                      }
+                    },
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+                      "name": "lastTokenIndex",
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+                      "src": "31267:14:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_uint256",
+                        "typeString": "uint256"
+                      }
+                    },
+                    "src": "31253:28:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_bool",
+                      "typeString": "bool"
+                    }
+                  },
+                  "falseBody": null,
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+                  "src": "31249:323:1",
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+                    "statements": [
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+                        "assignments": [
+                          1222
+                        ],
+                        "declarations": [
+                          {
+                            "constant": false,
+                            "id": 1222,
+                            "name": "lastTokenId",
+                            "nodeType": "VariableDeclaration",
+                            "scope": 1243,
+                            "src": "31297:19:1",
+                            "stateVariable": false,
+                            "storageLocation": "default",
+                            "typeDescriptions": {
+                              "typeIdentifier": "t_uint256",
+                              "typeString": "uint256"
+                            },
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+                              "name": "uint256",
+                              "nodeType": "ElementaryTypeName",
+                              "src": "31297:7:1",
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+                                "typeIdentifier": "t_uint256",
+                                "typeString": "uint256"
+                              }
+                            },
+                            "value": null,
+                            "visibility": "internal"
+                          }
+                        ],
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+                          "baseExpression": {
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+                              "id": 1223,
+                              "name": "_ownedTokens",
+                              "nodeType": "Identifier",
+                              "overloadedDeclarations": [],
+                              "referencedDeclaration": 981,
+                              "src": "31319:12:1",
+                              "typeDescriptions": {
+                                "typeIdentifier": "t_mapping$_t_address_$_t_array$_t_uint256_$dyn_storage_$",
+                                "typeString": "mapping(address => uint256[] storage ref)"
+                              }
+                            },
+                            "id": 1225,
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+                              "name": "from",
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+                              "referencedDeclaration": 1197,
+                              "src": "31332:4:1",
+                              "typeDescriptions": {
+                                "typeIdentifier": "t_address",
+                                "typeString": "address"
+                              }
+                            },
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+                            "nodeType": "IndexAccess",
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+                              "typeIdentifier": "t_array$_t_uint256_$dyn_storage",
+                              "typeString": "uint256[] storage ref"
+                            }
+                          },
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+                            "argumentTypes": null,
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+                            "name": "lastTokenIndex",
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+                            "src": "31338:14:1",
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+                              "typeIdentifier": "t_uint256",
+                              "typeString": "uint256"
+                            }
+                          },
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+                            "typeIdentifier": "t_uint256",
+                            "typeString": "uint256"
+                          }
+                        },
+                        "nodeType": "VariableDeclarationStatement",
+                        "src": "31297:56:1"
+                      },
+                      {
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+                              "baseExpression": {
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+                                "name": "_ownedTokens",
+                                "nodeType": "Identifier",
+                                "overloadedDeclarations": [],
+                                "referencedDeclaration": 981,
+                                "src": "31368:12:1",
+                                "typeDescriptions": {
+                                  "typeIdentifier": "t_mapping$_t_address_$_t_array$_t_uint256_$dyn_storage_$",
+                                  "typeString": "mapping(address => uint256[] storage ref)"
+                                }
+                              },
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+                                "argumentTypes": null,
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+                                "name": "from",
+                                "nodeType": "Identifier",
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+                                "referencedDeclaration": 1197,
+                                "src": "31381:4:1",
+                                "typeDescriptions": {
+                                  "typeIdentifier": "t_address",
+                                  "typeString": "address"
+                                }
+                              },
+                              "isConstant": false,
+                              "isLValue": true,
+                              "isPure": false,
+                              "lValueRequested": false,
+                              "nodeType": "IndexAccess",
+                              "src": "31368:18:1",
+                              "typeDescriptions": {
+                                "typeIdentifier": "t_array$_t_uint256_$dyn_storage",
+                                "typeString": "uint256[] storage ref"
+                              }
+                            },
+                            "id": 1233,
+                            "indexExpression": {
+                              "argumentTypes": null,
+                              "id": 1231,
+                              "name": "tokenIndex",
+                              "nodeType": "Identifier",
+                              "overloadedDeclarations": [],
+                              "referencedDeclaration": 1213,
+                              "src": "31387:10:1",
+                              "typeDescriptions": {
+                                "typeIdentifier": "t_uint256",
+                                "typeString": "uint256"
+                              }
+                            },
+                            "isConstant": false,
+                            "isLValue": true,
+                            "isPure": false,
+                            "lValueRequested": true,
+                            "nodeType": "IndexAccess",
+                            "src": "31368:30:1",
+                            "typeDescriptions": {
+                              "typeIdentifier": "t_uint256",
+                              "typeString": "uint256"
+                            }
+                          },
+                          "nodeType": "Assignment",
+                          "operator": "=",
+                          "rightHandSide": {
+                            "argumentTypes": null,
+                            "id": 1234,
+                            "name": "lastTokenId",
+                            "nodeType": "Identifier",
+                            "overloadedDeclarations": [],
+                            "referencedDeclaration": 1222,
+                            "src": "31401:11:1",
+                            "typeDescriptions": {
+                              "typeIdentifier": "t_uint256",
+                              "typeString": "uint256"
+                            }
+                          },
+                          "src": "31368:44:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_uint256",
+                            "typeString": "uint256"
+                          }
+                        },
+                        "id": 1236,
+                        "nodeType": "ExpressionStatement",
+                        "src": "31368:44:1"
+                      },
+                      {
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+                          "id": 1241,
+                          "isConstant": false,
+                          "isLValue": false,
+                          "isPure": false,
+                          "lValueRequested": false,
+                          "leftHandSide": {
+                            "argumentTypes": null,
+                            "baseExpression": {
+                              "argumentTypes": null,
+                              "id": 1237,
+                              "name": "_ownedTokensIndex",
+                              "nodeType": "Identifier",
+                              "overloadedDeclarations": [],
+                              "referencedDeclaration": 985,
+                              "src": "31484:17:1",
+                              "typeDescriptions": {
+                                "typeIdentifier": "t_mapping$_t_uint256_$_t_uint256_$",
+                                "typeString": "mapping(uint256 => uint256)"
+                              }
+                            },
+                            "id": 1239,
+                            "indexExpression": {
+                              "argumentTypes": null,
+                              "id": 1238,
+                              "name": "lastTokenId",
+                              "nodeType": "Identifier",
+                              "overloadedDeclarations": [],
+                              "referencedDeclaration": 1222,
+                              "src": "31502:11:1",
+                              "typeDescriptions": {
+                                "typeIdentifier": "t_uint256",
+                                "typeString": "uint256"
+                              }
+                            },
+                            "isConstant": false,
+                            "isLValue": true,
+                            "isPure": false,
+                            "lValueRequested": true,
+                            "nodeType": "IndexAccess",
+                            "src": "31484:30:1",
+                            "typeDescriptions": {
+                              "typeIdentifier": "t_uint256",
+                              "typeString": "uint256"
+                            }
+                          },
+                          "nodeType": "Assignment",
+                          "operator": "=",
+                          "rightHandSide": {
+                            "argumentTypes": null,
+                            "id": 1240,
+                            "name": "tokenIndex",
+                            "nodeType": "Identifier",
+                            "overloadedDeclarations": [],
+                            "referencedDeclaration": 1213,
+                            "src": "31517:10:1",
+                            "typeDescriptions": {
+                              "typeIdentifier": "t_uint256",
+                              "typeString": "uint256"
+                            }
+                          },
+                          "src": "31484:43:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_uint256",
+                            "typeString": "uint256"
+                          }
+                        },
+                        "id": 1242,
+                        "nodeType": "ExpressionStatement",
+                        "src": "31484:43:1"
+                      }
+                    ]
+                  }
+                },
+                {
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+                    "id": 1249,
+                    "isConstant": false,
+                    "isLValue": false,
+                    "isPure": false,
+                    "lValueRequested": false,
+                    "nodeType": "UnaryOperation",
+                    "operator": "--",
+                    "prefix": false,
+                    "src": "31658:27:1",
+                    "subExpression": {
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+                      "expression": {
+                        "argumentTypes": null,
+                        "baseExpression": {
+                          "argumentTypes": null,
+                          "id": 1245,
+                          "name": "_ownedTokens",
+                          "nodeType": "Identifier",
+                          "overloadedDeclarations": [],
+                          "referencedDeclaration": 981,
+                          "src": "31658:12:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_mapping$_t_address_$_t_array$_t_uint256_$dyn_storage_$",
+                            "typeString": "mapping(address => uint256[] storage ref)"
+                          }
+                        },
+                        "id": 1247,
+                        "indexExpression": {
+                          "argumentTypes": null,
+                          "id": 1246,
+                          "name": "from",
+                          "nodeType": "Identifier",
+                          "overloadedDeclarations": [],
+                          "referencedDeclaration": 1197,
+                          "src": "31671:4:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_address",
+                            "typeString": "address"
+                          }
+                        },
+                        "isConstant": false,
+                        "isLValue": true,
+                        "isPure": false,
+                        "lValueRequested": false,
+                        "nodeType": "IndexAccess",
+                        "src": "31658:18:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_array$_t_uint256_$dyn_storage",
+                          "typeString": "uint256[] storage ref"
+                        }
+                      },
+                      "id": 1248,
+                      "isConstant": false,
+                      "isLValue": true,
+                      "isPure": false,
+                      "lValueRequested": true,
+                      "memberName": "length",
+                      "nodeType": "MemberAccess",
+                      "referencedDeclaration": null,
+                      "src": "31658:25:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_uint256",
+                        "typeString": "uint256"
+                      }
+                    },
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_uint256",
+                      "typeString": "uint256"
+                    }
+                  },
+                  "id": 1250,
+                  "nodeType": "ExpressionStatement",
+                  "src": "31658:27:1"
+                }
+              ]
+            },
+            "documentation": "@dev Private function to remove a token from this extension's ownership-tracking data structures. Note that\nwhile the token is not assigned a new owner, the _ownedTokensIndex mapping is _not_ updated: this allows for\ngas optimizations e.g. when performing a transfer operation (avoiding double writes).\nThis has O(1) time complexity, but alters the order of the _ownedTokens array.\n@param from address representing the previous owner of the given token ID\n@param tokenId uint256 ID of the token to be removed from the tokens list of the given address",
+            "id": 1252,
+            "implemented": true,
+            "kind": "function",
+            "modifiers": [],
+            "name": "_removeTokenFromOwnerEnumeration",
+            "nodeType": "FunctionDefinition",
+            "parameters": {
+              "id": 1200,
+              "nodeType": "ParameterList",
+              "parameters": [
+                {
+                  "constant": false,
+                  "id": 1197,
+                  "name": "from",
+                  "nodeType": "VariableDeclaration",
+                  "scope": 1252,
+                  "src": "30815:12:1",
+                  "stateVariable": false,
+                  "storageLocation": "default",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_address",
+                    "typeString": "address"
+                  },
+                  "typeName": {
+                    "id": 1196,
+                    "name": "address",
+                    "nodeType": "ElementaryTypeName",
+                    "src": "30815:7:1",
+                    "stateMutability": "nonpayable",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_address",
+                      "typeString": "address"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                },
+                {
+                  "constant": false,
+                  "id": 1199,
+                  "name": "tokenId",
+                  "nodeType": "VariableDeclaration",
+                  "scope": 1252,
+                  "src": "30829:15:1",
+                  "stateVariable": false,
+                  "storageLocation": "default",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_uint256",
+                    "typeString": "uint256"
+                  },
+                  "typeName": {
+                    "id": 1198,
+                    "name": "uint256",
+                    "nodeType": "ElementaryTypeName",
+                    "src": "30829:7:1",
+                    "typeDescriptions": {
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+            "documentation": "@dev Internal function to burn a specific token.\nReverts if the token does not exist.\nDeprecated, use _burn(uint256) instead.\n@param owner owner of the token to burn\n@param tokenId uint256 ID of the token being burned by the msg.sender",
+            "id": 1447,
+            "implemented": true,
+            "kind": "function",
+            "modifiers": [],
+            "name": "_burn",
+            "nodeType": "FunctionDefinition",
+            "parameters": {
+              "id": 1422,
+              "nodeType": "ParameterList",
+              "parameters": [
+                {
+                  "constant": false,
+                  "id": 1419,
+                  "name": "owner",
+                  "nodeType": "VariableDeclaration",
+                  "scope": 1447,
+                  "src": "36227:13:1",
+                  "stateVariable": false,
+                  "storageLocation": "default",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_address",
+                    "typeString": "address"
+                  },
+                  "typeName": {
+                    "id": 1418,
+                    "name": "address",
+                    "nodeType": "ElementaryTypeName",
+                    "src": "36227:7:1",
+                    "stateMutability": "nonpayable",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_address",
+                      "typeString": "address"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                },
+                {
+                  "constant": false,
+                  "id": 1421,
+                  "name": "tokenId",
+                  "nodeType": "VariableDeclaration",
+                  "scope": 1447,
+                  "src": "36242:15:1",
+                  "stateVariable": false,
+                  "storageLocation": "default",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_uint256",
+                    "typeString": "uint256"
+                  },
+                  "typeName": {
+                    "id": 1420,
+                    "name": "uint256",
+                    "nodeType": "ElementaryTypeName",
+                    "src": "36242:7:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_uint256",
+                      "typeString": "uint256"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                }
+              ],
+              "src": "36226:32:1"
+            },
+            "returnParameters": {
+              "id": 1423,
+              "nodeType": "ParameterList",
+              "parameters": [],
+              "src": "36268:0:1"
+            },
+            "scope": 1448,
+            "src": "36212:240:1",
+            "stateMutability": "nonpayable",
+            "superFunction": 811,
+            "visibility": "internal"
+          }
+        ],
+        "scope": 1469,
+        "src": "33817:2637:1"
+      },
+      {
+        "id": 1449,
+        "literals": [
+          "solidity",
+          "^",
+          "0.5",
+          ".0"
+        ],
+        "nodeType": "PragmaDirective",
+        "src": "36518:23:1"
+      },
+      {
+        "baseContracts": [
+          {
+            "arguments": null,
+            "baseName": {
+              "contractScope": null,
+              "id": 1450,
+              "name": "ERC721",
+              "nodeType": "UserDefinedTypeName",
+              "referencedDeclaration": 944,
+              "src": "36838:6:1",
+              "typeDescriptions": {
+                "typeIdentifier": "t_contract$_ERC721_$944",
+                "typeString": "contract ERC721"
+              }
+            },
+            "id": 1451,
+            "nodeType": "InheritanceSpecifier",
+            "src": "36838:6:1"
+          },
+          {
+            "arguments": null,
+            "baseName": {
+              "contractScope": null,
+              "id": 1452,
+              "name": "ERC721Enumerable",
+              "nodeType": "UserDefinedTypeName",
+              "referencedDeclaration": 1302,
+              "src": "36846:16:1",
+              "typeDescriptions": {
+                "typeIdentifier": "t_contract$_ERC721Enumerable_$1302",
+                "typeString": "contract ERC721Enumerable"
+              }
+            },
+            "id": 1453,
+            "nodeType": "InheritanceSpecifier",
+            "src": "36846:16:1"
+          },
+          {
+            "arguments": null,
+            "baseName": {
+              "contractScope": null,
+              "id": 1454,
+              "name": "ERC721Metadata",
+              "nodeType": "UserDefinedTypeName",
+              "referencedDeclaration": 1448,
+              "src": "36864:14:1",
+              "typeDescriptions": {
+                "typeIdentifier": "t_contract$_ERC721Metadata_$1448",
+                "typeString": "contract ERC721Metadata"
+              }
+            },
+            "id": 1455,
+            "nodeType": "InheritanceSpecifier",
+            "src": "36864:14:1"
+          }
+        ],
+        "contractDependencies": [
+          944,
+          969,
+          23,
+          124,
+          386,
+          1302,
+          1323,
+          1448
+        ],
+        "contractKind": "contract",
+        "documentation": "@title Full ERC721 Token\nThis implementation includes all the required and some optional functionality of the ERC721 standard\nMoreover, it includes approve all functionality using operator terminology\n@dev see https://eips.ethereum.org/EIPS/eip-721",
+        "fullyImplemented": true,
+        "id": 1468,
+        "linearizedBaseContracts": [
+          1468,
+          1448,
+          1323,
+          1302,
+          969,
+          944,
+          124,
+          386,
+          23
+        ],
+        "name": "ERC721Full",
+        "nodeType": "ContractDefinition",
+        "nodes": [
+          {
+            "body": {
+              "id": 1466,
+              "nodeType": "Block",
+              "src": "36976:64:1",
+              "statements": []
+            },
+            "documentation": null,
+            "id": 1467,
+            "implemented": true,
+            "kind": "constructor",
+            "modifiers": [
+              {
+                "arguments": [
+                  {
+                    "argumentTypes": null,
+                    "id": 1462,
+                    "name": "name",
+                    "nodeType": "Identifier",
+                    "overloadedDeclarations": [],
+                    "referencedDeclaration": 1457,
+                    "src": "36962:4:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_string_memory_ptr",
+                      "typeString": "string memory"
+                    }
+                  },
+                  {
+                    "argumentTypes": null,
+                    "id": 1463,
+                    "name": "symbol",
+                    "nodeType": "Identifier",
+                    "overloadedDeclarations": [],
+                    "referencedDeclaration": 1459,
+                    "src": "36968:6:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_string_memory_ptr",
+                      "typeString": "string memory"
+                    }
+                  }
+                ],
+                "id": 1464,
+                "modifierName": {
+                  "argumentTypes": null,
+                  "id": 1461,
+                  "name": "ERC721Metadata",
+                  "nodeType": "Identifier",
+                  "overloadedDeclarations": [],
+                  "referencedDeclaration": 1448,
+                  "src": "36947:14:1",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_type$_t_contract$_ERC721Metadata_$1448_$",
+                    "typeString": "type(contract ERC721Metadata)"
+                  }
+                },
+                "nodeType": "ModifierInvocation",
+                "src": "36947:28:1"
+              }
+            ],
+            "name": "",
+            "nodeType": "FunctionDefinition",
+            "parameters": {
+              "id": 1460,
+              "nodeType": "ParameterList",
+              "parameters": [
+                {
+                  "constant": false,
+                  "id": 1457,
+                  "name": "name",
+                  "nodeType": "VariableDeclaration",
+                  "scope": 1467,
+                  "src": "36898:18:1",
+                  "stateVariable": false,
+                  "storageLocation": "memory",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_string_memory_ptr",
+                    "typeString": "string"
+                  },
+                  "typeName": {
+                    "id": 1456,
+                    "name": "string",
+                    "nodeType": "ElementaryTypeName",
+                    "src": "36898:6:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_string_storage_ptr",
+                      "typeString": "string"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                },
+                {
+                  "constant": false,
+                  "id": 1459,
+                  "name": "symbol",
+                  "nodeType": "VariableDeclaration",
+                  "scope": 1467,
+                  "src": "36918:20:1",
+                  "stateVariable": false,
+                  "storageLocation": "memory",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_string_memory_ptr",
+                    "typeString": "string"
+                  },
+                  "typeName": {
+                    "id": 1458,
+                    "name": "string",
+                    "nodeType": "ElementaryTypeName",
+                    "src": "36918:6:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_string_storage_ptr",
+                      "typeString": "string"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                }
+              ],
+              "src": "36897:42:1"
+            },
+            "returnParameters": {
+              "id": 1465,
+              "nodeType": "ParameterList",
+              "parameters": [],
+              "src": "36976:0:1"
+            },
+            "scope": 1468,
+            "src": "36885:155:1",
+            "stateMutability": "nonpayable",
+            "superFunction": null,
+            "visibility": "public"
+          }
+        ],
+        "scope": 1469,
+        "src": "36815:227:1"
+      }
+    ],
+    "src": "61:36982:1"
+  },
+  "compiler": {
+    "name": "solc",
+    "version": "0.5.0+commit.1d4f565a.Emscripten.clang"
+  },
+  "networks": {},
+  "schemaVersion": "3.0.2",
+  "updatedAt": "2019-09-05T15:01:08.546Z",
+  "devdoc": {
+    "author": "Matt Condon (@shrugs)",
+    "details": "Provides counters that can only be incremented or decremented by one. This can be used e.g. to track the number of elements in a mapping, issuing ERC721 ids, or counting request ids. * Include with `using Counters for Counters.Counter;` Since it is not possible to overflow a 256 bit integer with increments of one, `increment` can skip the SafeMath overflow check, thereby saving gas. This does assume however correct usage, in that the underlying `_value` is never directly accessed.",
+    "methods": {},
+    "title": "Counters"
+  },
+  "userdoc": {
+    "methods": {}
+  }
+}
\ No newline at end of file
diff --git a/src/abis/ERC165.json b/src/abis/ERC165.json
new file mode 100644
index 0000000..fdc7a50
--- /dev/null
+++ b/src/abis/ERC165.json
@@ -0,0 +1,37478 @@
+{
+  "contractName": "ERC165",
+  "abi": [
+    {
+      "inputs": [],
+      "payable": false,
+      "stateMutability": "nonpayable",
+      "type": "constructor"
+    },
+    {
+      "constant": true,
+      "inputs": [
+        {
+          "name": "interfaceId",
+          "type": "bytes4"
+        }
+      ],
+      "name": "supportsInterface",
+      "outputs": [
+        {
+          "name": "",
+          "type": "bool"
+        }
+      ],
+      "payable": false,
+      "stateMutability": "view",
+      "type": "function"
+    }
+  ],
+  "bytecode": "0x",
+  "deployedBytecode": "0x",
+  "sourceMap": "",
+  "deployedSourceMap": "",
+  "source": "\n// File: @openzeppelin/contracts/introspection/IERC165.sol\n\npragma solidity ^0.5.0;\n\n/**\n * @dev Interface of the ERC165 standard, as defined in the\n * [EIP](https://eips.ethereum.org/EIPS/eip-165).\n *\n * Implementers can declare support of contract interfaces, which can then be\n * queried by others (`ERC165Checker`).\n *\n * For an implementation, see `ERC165`.\n */\ninterface IERC165 {\n    /**\n     * @dev Returns true if this contract implements the interface defined by\n     * `interfaceId`. See the corresponding\n     * [EIP section](https://eips.ethereum.org/EIPS/eip-165#how-interfaces-are-identified)\n     * to learn more about how these ids are created.\n     *\n     * This function call must use less than 30 000 gas.\n     */\n    function supportsInterface(bytes4 interfaceId) external view returns (bool);\n}\n\n// File: @openzeppelin/contracts/token/ERC721/IERC721.sol\n\npragma solidity ^0.5.0;\n\n\n/**\n * @dev Required interface of an ERC721 compliant contract.\n */\ncontract IERC721 is IERC165 {\n    event Transfer(address indexed from, address indexed to, uint256 indexed tokenId);\n    event Approval(address indexed owner, address indexed approved, uint256 indexed tokenId);\n    event ApprovalForAll(address indexed owner, address indexed operator, bool approved);\n\n    /**\n     * @dev Returns the number of NFTs in `owner`'s account.\n     */\n    function balanceOf(address owner) public view returns (uint256 balance);\n\n    /**\n     * @dev Returns the owner of the NFT specified by `tokenId`.\n     */\n    function ownerOf(uint256 tokenId) public view returns (address owner);\n\n    /**\n     * @dev Transfers a specific NFT (`tokenId`) from one account (`from`) to\n     * another (`to`).\n     *\n     * \n     *\n     * Requirements:\n     * - `from`, `to` cannot be zero.\n     * - `tokenId` must be owned by `from`.\n     * - If the caller is not `from`, it must be have been allowed to move this\n     * NFT by either `approve` or `setApproveForAll`.\n     */\n    function safeTransferFrom(address from, address to, uint256 tokenId) public;\n    /**\n     * @dev Transfers a specific NFT (`tokenId`) from one account (`from`) to\n     * another (`to`).\n     *\n     * Requirements:\n     * - If the caller is not `from`, it must be approved to move this NFT by\n     * either `approve` or `setApproveForAll`.\n     */\n    function transferFrom(address from, address to, uint256 tokenId) public;\n    function approve(address to, uint256 tokenId) public;\n    function getApproved(uint256 tokenId) public view returns (address operator);\n\n    function setApprovalForAll(address operator, bool _approved) public;\n    function isApprovedForAll(address owner, address operator) public view returns (bool);\n\n\n    function safeTransferFrom(address from, address to, uint256 tokenId, bytes memory data) public;\n}\n\n// File: @openzeppelin/contracts/token/ERC721/IERC721Receiver.sol\n\npragma solidity ^0.5.0;\n\n/**\n * @title ERC721 token receiver interface\n * @dev Interface for any contract that wants to support safeTransfers\n * from ERC721 asset contracts.\n */\ncontract IERC721Receiver {\n    /**\n     * @notice Handle the receipt of an NFT\n     * @dev The ERC721 smart contract calls this function on the recipient\n     * after a `safeTransfer`. This function MUST return the function selector,\n     * otherwise the caller will revert the transaction. The selector to be\n     * returned can be obtained as `this.onERC721Received.selector`. This\n     * function MAY throw to revert and reject the transfer.\n     * Note: the ERC721 contract address is always the message sender.\n     * @param operator The address which called `safeTransferFrom` function\n     * @param from The address which previously owned the token\n     * @param tokenId The NFT identifier which is being transferred\n     * @param data Additional data with no specified format\n     * @return bytes4 `bytes4(keccak256(\"onERC721Received(address,address,uint256,bytes)\"))`\n     */\n    function onERC721Received(address operator, address from, uint256 tokenId, bytes memory data)\n    public returns (bytes4);\n}\n\n// File: @openzeppelin/contracts/math/SafeMath.sol\n\npragma solidity ^0.5.0;\n\n/**\n * @dev Wrappers over Solidity's arithmetic operations with added overflow\n * checks.\n *\n * Arithmetic operations in Solidity wrap on overflow. This can easily result\n * in bugs, because programmers usually assume that an overflow raises an\n * error, which is the standard behavior in high level programming languages.\n * `SafeMath` restores this intuition by reverting the transaction when an\n * operation overflows.\n *\n * Using this library instead of the unchecked operations eliminates an entire\n * class of bugs, so it's recommended to use it always.\n */\nlibrary SafeMath {\n    /**\n     * @dev Returns the addition of two unsigned integers, reverting on\n     * overflow.\n     *\n     * Counterpart to Solidity's `+` operator.\n     *\n     * Requirements:\n     * - Addition cannot overflow.\n     */\n    function add(uint256 a, uint256 b) internal pure returns (uint256) {\n        uint256 c = a + b;\n        require(c >= a, \"SafeMath: addition overflow\");\n\n        return c;\n    }\n\n    /**\n     * @dev Returns the subtraction of two unsigned integers, reverting on\n     * overflow (when the result is negative).\n     *\n     * Counterpart to Solidity's `-` operator.\n     *\n     * Requirements:\n     * - Subtraction cannot overflow.\n     */\n    function sub(uint256 a, uint256 b) internal pure returns (uint256) {\n        require(b <= a, \"SafeMath: subtraction overflow\");\n        uint256 c = a - b;\n\n        return c;\n    }\n\n    /**\n     * @dev Returns the multiplication of two unsigned integers, reverting on\n     * overflow.\n     *\n     * Counterpart to Solidity's `*` operator.\n     *\n     * Requirements:\n     * - Multiplication cannot overflow.\n     */\n    function mul(uint256 a, uint256 b) internal pure returns (uint256) {\n        // Gas optimization: this is cheaper than requiring 'a' not being zero, but the\n        // benefit is lost if 'b' is also tested.\n        // See: https://github.com/OpenZeppelin/openzeppelin-contracts/pull/522\n        if (a == 0) {\n            return 0;\n        }\n\n        uint256 c = a * b;\n        require(c / a == b, \"SafeMath: multiplication overflow\");\n\n        return c;\n    }\n\n    /**\n     * @dev Returns the integer division of two unsigned integers. Reverts on\n     * division by zero. The result is rounded towards zero.\n     *\n     * Counterpart to Solidity's `/` operator. Note: this function uses a\n     * `revert` opcode (which leaves remaining gas untouched) while Solidity\n     * uses an invalid opcode to revert (consuming all remaining gas).\n     *\n     * Requirements:\n     * - The divisor cannot be zero.\n     */\n    function div(uint256 a, uint256 b) internal pure returns (uint256) {\n        // Solidity only automatically asserts when dividing by 0\n        require(b > 0, \"SafeMath: division by zero\");\n        uint256 c = a / b;\n        // assert(a == b * c + a % b); // There is no case in which this doesn't hold\n\n        return c;\n    }\n\n    /**\n     * @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo),\n     * Reverts when dividing by zero.\n     *\n     * Counterpart to Solidity's `%` operator. This function uses a `revert`\n     * opcode (which leaves remaining gas untouched) while Solidity uses an\n     * invalid opcode to revert (consuming all remaining gas).\n     *\n     * Requirements:\n     * - The divisor cannot be zero.\n     */\n    function mod(uint256 a, uint256 b) internal pure returns (uint256) {\n        require(b != 0, \"SafeMath: modulo by zero\");\n        return a % b;\n    }\n}\n\n// File: @openzeppelin/contracts/utils/Address.sol\n\npragma solidity ^0.5.0;\n\n/**\n * @dev Collection of functions related to the address type,\n */\nlibrary Address {\n    /**\n     * @dev Returns true if `account` is a contract.\n     *\n     * This test is non-exhaustive, and there may be false-negatives: during the\n     * execution of a contract's constructor, its address will be reported as\n     * not containing a contract.\n     *\n     * > It is unsafe to assume that an address for which this function returns\n     * false is an externally-owned account (EOA) and not a contract.\n     */\n    function isContract(address account) internal view returns (bool) {\n        // This method relies in extcodesize, which returns 0 for contracts in\n        // construction, since the code is only stored at the end of the\n        // constructor execution.\n\n        uint256 size;\n        // solhint-disable-next-line no-inline-assembly\n        assembly { size := extcodesize(account) }\n        return size > 0;\n    }\n}\n\n// File: @openzeppelin/contracts/drafts/Counters.sol\n\npragma solidity ^0.5.0;\n\n\n/**\n * @title Counters\n * @author Matt Condon (@shrugs)\n * @dev Provides counters that can only be incremented or decremented by one. This can be used e.g. to track the number\n * of elements in a mapping, issuing ERC721 ids, or counting request ids.\n *\n * Include with `using Counters for Counters.Counter;`\n * Since it is not possible to overflow a 256 bit integer with increments of one, `increment` can skip the SafeMath\n * overflow check, thereby saving gas. This does assume however correct usage, in that the underlying `_value` is never\n * directly accessed.\n */\nlibrary Counters {\n    using SafeMath for uint256;\n\n    struct Counter {\n        // This variable should never be directly accessed by users of the library: interactions must be restricted to\n        // the library's function. As of Solidity v0.5.2, this cannot be enforced, though there is a proposal to add\n        // this feature: see https://github.com/ethereum/solidity/issues/4637\n        uint256 _value; // default: 0\n    }\n\n    function current(Counter storage counter) internal view returns (uint256) {\n        return counter._value;\n    }\n\n    function increment(Counter storage counter) internal {\n        counter._value += 1;\n    }\n\n    function decrement(Counter storage counter) internal {\n        counter._value = counter._value.sub(1);\n    }\n}\n\n// File: @openzeppelin/contracts/introspection/ERC165.sol\n\npragma solidity ^0.5.0;\n\n\n/**\n * @dev Implementation of the `IERC165` interface.\n *\n * Contracts may inherit from this and call `_registerInterface` to declare\n * their support of an interface.\n */\ncontract ERC165 is IERC165 {\n    /*\n     * bytes4(keccak256('supportsInterface(bytes4)')) == 0x01ffc9a7\n     */\n    bytes4 private constant _INTERFACE_ID_ERC165 = 0x01ffc9a7;\n\n    /**\n     * @dev Mapping of interface ids to whether or not it's supported.\n     */\n    mapping(bytes4 => bool) private _supportedInterfaces;\n\n    constructor () internal {\n        // Derived contracts need only register support for their own interfaces,\n        // we register support for ERC165 itself here\n        _registerInterface(_INTERFACE_ID_ERC165);\n    }\n\n    /**\n     * @dev See `IERC165.supportsInterface`.\n     *\n     * Time complexity O(1), guaranteed to always use less than 30 000 gas.\n     */\n    function supportsInterface(bytes4 interfaceId) external view returns (bool) {\n        return _supportedInterfaces[interfaceId];\n    }\n\n    /**\n     * @dev Registers the contract as an implementer of the interface defined by\n     * `interfaceId`. Support of the actual ERC165 interface is automatic and\n     * registering its interface id is not required.\n     *\n     * See `IERC165.supportsInterface`.\n     *\n     * Requirements:\n     *\n     * - `interfaceId` cannot be the ERC165 invalid interface (`0xffffffff`).\n     */\n    function _registerInterface(bytes4 interfaceId) internal {\n        require(interfaceId != 0xffffffff, \"ERC165: invalid interface id\");\n        _supportedInterfaces[interfaceId] = true;\n    }\n}\n\n// File: @openzeppelin/contracts/token/ERC721/ERC721.sol\n\npragma solidity ^0.5.0;\n\n\n\n\n\n\n\n/**\n * @title ERC721 Non-Fungible Token Standard basic implementation\n * @dev see https://eips.ethereum.org/EIPS/eip-721\n */\ncontract ERC721 is ERC165, IERC721 {\n    using SafeMath for uint256;\n    using Address for address;\n    using Counters for Counters.Counter;\n\n    // Equals to `bytes4(keccak256(\"onERC721Received(address,address,uint256,bytes)\"))`\n    // which can be also obtained as `IERC721Receiver(0).onERC721Received.selector`\n    bytes4 private constant _ERC721_RECEIVED = 0x150b7a02;\n\n    // Mapping from token ID to owner\n    mapping (uint256 => address) private _tokenOwner;\n\n    // Mapping from token ID to approved address\n    mapping (uint256 => address) private _tokenApprovals;\n\n    // Mapping from owner to number of owned token\n    mapping (address => Counters.Counter) private _ownedTokensCount;\n\n    // Mapping from owner to operator approvals\n    mapping (address => mapping (address => bool)) private _operatorApprovals;\n\n    /*\n     *     bytes4(keccak256('balanceOf(address)')) == 0x70a08231\n     *     bytes4(keccak256('ownerOf(uint256)')) == 0x6352211e\n     *     bytes4(keccak256('approve(address,uint256)')) == 0x095ea7b3\n     *     bytes4(keccak256('getApproved(uint256)')) == 0x081812fc\n     *     bytes4(keccak256('setApprovalForAll(address,bool)')) == 0xa22cb465\n     *     bytes4(keccak256('isApprovedForAll(address,address)')) == 0xe985e9c\n     *     bytes4(keccak256('transferFrom(address,address,uint256)')) == 0x23b872dd\n     *     bytes4(keccak256('safeTransferFrom(address,address,uint256)')) == 0x42842e0e\n     *     bytes4(keccak256('safeTransferFrom(address,address,uint256,bytes)')) == 0xb88d4fde\n     *\n     *     => 0x70a08231 ^ 0x6352211e ^ 0x095ea7b3 ^ 0x081812fc ^\n     *        0xa22cb465 ^ 0xe985e9c ^ 0x23b872dd ^ 0x42842e0e ^ 0xb88d4fde == 0x80ac58cd\n     */\n    bytes4 private constant _INTERFACE_ID_ERC721 = 0x80ac58cd;\n\n    constructor () public {\n        // register the supported interfaces to conform to ERC721 via ERC165\n        _registerInterface(_INTERFACE_ID_ERC721);\n    }\n\n    /**\n     * @dev Gets the balance of the specified address.\n     * @param owner address to query the balance of\n     * @return uint256 representing the amount owned by the passed address\n     */\n    function balanceOf(address owner) public view returns (uint256) {\n        require(owner != address(0), \"ERC721: balance query for the zero address\");\n\n        return _ownedTokensCount[owner].current();\n    }\n\n    /**\n     * @dev Gets the owner of the specified token ID.\n     * @param tokenId uint256 ID of the token to query the owner of\n     * @return address currently marked as the owner of the given token ID\n     */\n    function ownerOf(uint256 tokenId) public view returns (address) {\n        address owner = _tokenOwner[tokenId];\n        require(owner != address(0), \"ERC721: owner query for nonexistent token\");\n\n        return owner;\n    }\n\n    /**\n     * @dev Approves another address to transfer the given token ID\n     * The zero address indicates there is no approved address.\n     * There can only be one approved address per token at a given time.\n     * Can only be called by the token owner or an approved operator.\n     * @param to address to be approved for the given token ID\n     * @param tokenId uint256 ID of the token to be approved\n     */\n    function approve(address to, uint256 tokenId) public {\n        address owner = ownerOf(tokenId);\n        require(to != owner, \"ERC721: approval to current owner\");\n\n        require(msg.sender == owner || isApprovedForAll(owner, msg.sender),\n            \"ERC721: approve caller is not owner nor approved for all\"\n        );\n\n        _tokenApprovals[tokenId] = to;\n        emit Approval(owner, to, tokenId);\n    }\n\n    /**\n     * @dev Gets the approved address for a token ID, or zero if no address set\n     * Reverts if the token ID does not exist.\n     * @param tokenId uint256 ID of the token to query the approval of\n     * @return address currently approved for the given token ID\n     */\n    function getApproved(uint256 tokenId) public view returns (address) {\n        require(_exists(tokenId), \"ERC721: approved query for nonexistent token\");\n\n        return _tokenApprovals[tokenId];\n    }\n\n    /**\n     * @dev Sets or unsets the approval of a given operator\n     * An operator is allowed to transfer all tokens of the sender on their behalf.\n     * @param to operator address to set the approval\n     * @param approved representing the status of the approval to be set\n     */\n    function setApprovalForAll(address to, bool approved) public {\n        require(to != msg.sender, \"ERC721: approve to caller\");\n\n        _operatorApprovals[msg.sender][to] = approved;\n        emit ApprovalForAll(msg.sender, to, approved);\n    }\n\n    /**\n     * @dev Tells whether an operator is approved by a given owner.\n     * @param owner owner address which you want to query the approval of\n     * @param operator operator address which you want to query the approval of\n     * @return bool whether the given operator is approved by the given owner\n     */\n    function isApprovedForAll(address owner, address operator) public view returns (bool) {\n        return _operatorApprovals[owner][operator];\n    }\n\n    /**\n     * @dev Transfers the ownership of a given token ID to another address.\n     * Usage of this method is discouraged, use `safeTransferFrom` whenever possible.\n     * Requires the msg.sender to be the owner, approved, or operator.\n     * @param from current owner of the token\n     * @param to address to receive the ownership of the given token ID\n     * @param tokenId uint256 ID of the token to be transferred\n     */\n    function transferFrom(address from, address to, uint256 tokenId) public {\n        //solhint-disable-next-line max-line-length\n        require(_isApprovedOrOwner(msg.sender, tokenId), \"ERC721: transfer caller is not owner nor approved\");\n\n        _transferFrom(from, to, tokenId);\n    }\n\n    /**\n     * @dev Safely transfers the ownership of a given token ID to another address\n     * If the target address is a contract, it must implement `onERC721Received`,\n     * which is called upon a safe transfer, and return the magic value\n     * `bytes4(keccak256(\"onERC721Received(address,address,uint256,bytes)\"))`; otherwise,\n     * the transfer is reverted.\n     * Requires the msg.sender to be the owner, approved, or operator\n     * @param from current owner of the token\n     * @param to address to receive the ownership of the given token ID\n     * @param tokenId uint256 ID of the token to be transferred\n     */\n    function safeTransferFrom(address from, address to, uint256 tokenId) public {\n        safeTransferFrom(from, to, tokenId, \"\");\n    }\n\n    /**\n     * @dev Safely transfers the ownership of a given token ID to another address\n     * If the target address is a contract, it must implement `onERC721Received`,\n     * which is called upon a safe transfer, and return the magic value\n     * `bytes4(keccak256(\"onERC721Received(address,address,uint256,bytes)\"))`; otherwise,\n     * the transfer is reverted.\n     * Requires the msg.sender to be the owner, approved, or operator\n     * @param from current owner of the token\n     * @param to address to receive the ownership of the given token ID\n     * @param tokenId uint256 ID of the token to be transferred\n     * @param _data bytes data to send along with a safe transfer check\n     */\n    function safeTransferFrom(address from, address to, uint256 tokenId, bytes memory _data) public {\n        transferFrom(from, to, tokenId);\n        require(_checkOnERC721Received(from, to, tokenId, _data), \"ERC721: transfer to non ERC721Receiver implementer\");\n    }\n\n    /**\n     * @dev Returns whether the specified token exists.\n     * @param tokenId uint256 ID of the token to query the existence of\n     * @return bool whether the token exists\n     */\n    function _exists(uint256 tokenId) internal view returns (bool) {\n        address owner = _tokenOwner[tokenId];\n        return owner != address(0);\n    }\n\n    /**\n     * @dev Returns whether the given spender can transfer a given token ID.\n     * @param spender address of the spender to query\n     * @param tokenId uint256 ID of the token to be transferred\n     * @return bool whether the msg.sender is approved for the given token ID,\n     * is an operator of the owner, or is the owner of the token\n     */\n    function _isApprovedOrOwner(address spender, uint256 tokenId) internal view returns (bool) {\n        require(_exists(tokenId), \"ERC721: operator query for nonexistent token\");\n        address owner = ownerOf(tokenId);\n        return (spender == owner || getApproved(tokenId) == spender || isApprovedForAll(owner, spender));\n    }\n\n    /**\n     * @dev Internal function to mint a new token.\n     * Reverts if the given token ID already exists.\n     * @param to The address that will own the minted token\n     * @param tokenId uint256 ID of the token to be minted\n     */\n    function _mint(address to, uint256 tokenId) internal {\n        require(to != address(0), \"ERC721: mint to the zero address\");\n        require(!_exists(tokenId), \"ERC721: token already minted\");\n\n        _tokenOwner[tokenId] = to;\n        _ownedTokensCount[to].increment();\n\n        emit Transfer(address(0), to, tokenId);\n    }\n\n    /**\n     * @dev Internal function to burn a specific token.\n     * Reverts if the token does not exist.\n     * Deprecated, use _burn(uint256) instead.\n     * @param owner owner of the token to burn\n     * @param tokenId uint256 ID of the token being burned\n     */\n    function _burn(address owner, uint256 tokenId) internal {\n        require(ownerOf(tokenId) == owner, \"ERC721: burn of token that is not own\");\n\n        _clearApproval(tokenId);\n\n        _ownedTokensCount[owner].decrement();\n        _tokenOwner[tokenId] = address(0);\n\n        emit Transfer(owner, address(0), tokenId);\n    }\n\n    /**\n     * @dev Internal function to burn a specific token.\n     * Reverts if the token does not exist.\n     * @param tokenId uint256 ID of the token being burned\n     */\n    function _burn(uint256 tokenId) internal {\n        _burn(ownerOf(tokenId), tokenId);\n    }\n\n    /**\n     * @dev Internal function to transfer ownership of a given token ID to another address.\n     * As opposed to transferFrom, this imposes no restrictions on msg.sender.\n     * @param from current owner of the token\n     * @param to address to receive the ownership of the given token ID\n     * @param tokenId uint256 ID of the token to be transferred\n     */\n    function _transferFrom(address from, address to, uint256 tokenId) internal {\n        require(ownerOf(tokenId) == from, \"ERC721: transfer of token that is not own\");\n        require(to != address(0), \"ERC721: transfer to the zero address\");\n\n        _clearApproval(tokenId);\n\n        _ownedTokensCount[from].decrement();\n        _ownedTokensCount[to].increment();\n\n        _tokenOwner[tokenId] = to;\n\n        emit Transfer(from, to, tokenId);\n    }\n\n    /**\n     * @dev Internal function to invoke `onERC721Received` on a target address.\n     * The call is not executed if the target address is not a contract.\n     *\n     * This function is deprecated.\n     * @param from address representing the previous owner of the given token ID\n     * @param to target address that will receive the tokens\n     * @param tokenId uint256 ID of the token to be transferred\n     * @param _data bytes optional data to send along with the call\n     * @return bool whether the call correctly returned the expected magic value\n     */\n    function _checkOnERC721Received(address from, address to, uint256 tokenId, bytes memory _data)\n        internal returns (bool)\n    {\n        if (!to.isContract()) {\n            return true;\n        }\n\n        bytes4 retval = IERC721Receiver(to).onERC721Received(msg.sender, from, tokenId, _data);\n        return (retval == _ERC721_RECEIVED);\n    }\n\n    /**\n     * @dev Private function to clear current approval of a given token ID.\n     * @param tokenId uint256 ID of the token to be transferred\n     */\n    function _clearApproval(uint256 tokenId) private {\n        if (_tokenApprovals[tokenId] != address(0)) {\n            _tokenApprovals[tokenId] = address(0);\n        }\n    }\n}\n\n// File: @openzeppelin/contracts/token/ERC721/IERC721Enumerable.sol\n\npragma solidity ^0.5.0;\n\n\n/**\n * @title ERC-721 Non-Fungible Token Standard, optional enumeration extension\n * @dev See https://eips.ethereum.org/EIPS/eip-721\n */\ncontract IERC721Enumerable is IERC721 {\n    function totalSupply() public view returns (uint256);\n    function tokenOfOwnerByIndex(address owner, uint256 index) public view returns (uint256 tokenId);\n\n    function tokenByIndex(uint256 index) public view returns (uint256);\n}\n\n// File: @openzeppelin/contracts/token/ERC721/ERC721Enumerable.sol\n\npragma solidity ^0.5.0;\n\n\n\n\n/**\n * @title ERC-721 Non-Fungible Token with optional enumeration extension logic\n * @dev See https://eips.ethereum.org/EIPS/eip-721\n */\ncontract ERC721Enumerable is ERC165, ERC721, IERC721Enumerable {\n    // Mapping from owner to list of owned token IDs\n    mapping(address => uint256[]) private _ownedTokens;\n\n    // Mapping from token ID to index of the owner tokens list\n    mapping(uint256 => uint256) private _ownedTokensIndex;\n\n    // Array with all token ids, used for enumeration\n    uint256[] private _allTokens;\n\n    // Mapping from token id to position in the allTokens array\n    mapping(uint256 => uint256) private _allTokensIndex;\n\n    /*\n     *     bytes4(keccak256('totalSupply()')) == 0x18160ddd\n     *     bytes4(keccak256('tokenOfOwnerByIndex(address,uint256)')) == 0x2f745c59\n     *     bytes4(keccak256('tokenByIndex(uint256)')) == 0x4f6ccce7\n     *\n     *     => 0x18160ddd ^ 0x2f745c59 ^ 0x4f6ccce7 == 0x780e9d63\n     */\n    bytes4 private constant _INTERFACE_ID_ERC721_ENUMERABLE = 0x780e9d63;\n\n    /**\n     * @dev Constructor function.\n     */\n    constructor () public {\n        // register the supported interface to conform to ERC721Enumerable via ERC165\n        _registerInterface(_INTERFACE_ID_ERC721_ENUMERABLE);\n    }\n\n    /**\n     * @dev Gets the token ID at a given index of the tokens list of the requested owner.\n     * @param owner address owning the tokens list to be accessed\n     * @param index uint256 representing the index to be accessed of the requested tokens list\n     * @return uint256 token ID at the given index of the tokens list owned by the requested address\n     */\n    function tokenOfOwnerByIndex(address owner, uint256 index) public view returns (uint256) {\n        require(index < balanceOf(owner), \"ERC721Enumerable: owner index out of bounds\");\n        return _ownedTokens[owner][index];\n    }\n\n    /**\n     * @dev Gets the total amount of tokens stored by the contract.\n     * @return uint256 representing the total amount of tokens\n     */\n    function totalSupply() public view returns (uint256) {\n        return _allTokens.length;\n    }\n\n    /**\n     * @dev Gets the token ID at a given index of all the tokens in this contract\n     * Reverts if the index is greater or equal to the total number of tokens.\n     * @param index uint256 representing the index to be accessed of the tokens list\n     * @return uint256 token ID at the given index of the tokens list\n     */\n    function tokenByIndex(uint256 index) public view returns (uint256) {\n        require(index < totalSupply(), \"ERC721Enumerable: global index out of bounds\");\n        return _allTokens[index];\n    }\n\n    /**\n     * @dev Internal function to transfer ownership of a given token ID to another address.\n     * As opposed to transferFrom, this imposes no restrictions on msg.sender.\n     * @param from current owner of the token\n     * @param to address to receive the ownership of the given token ID\n     * @param tokenId uint256 ID of the token to be transferred\n     */\n    function _transferFrom(address from, address to, uint256 tokenId) internal {\n        super._transferFrom(from, to, tokenId);\n\n        _removeTokenFromOwnerEnumeration(from, tokenId);\n\n        _addTokenToOwnerEnumeration(to, tokenId);\n    }\n\n    /**\n     * @dev Internal function to mint a new token.\n     * Reverts if the given token ID already exists.\n     * @param to address the beneficiary that will own the minted token\n     * @param tokenId uint256 ID of the token to be minted\n     */\n    function _mint(address to, uint256 tokenId) internal {\n        super._mint(to, tokenId);\n\n        _addTokenToOwnerEnumeration(to, tokenId);\n\n        _addTokenToAllTokensEnumeration(tokenId);\n    }\n\n    /**\n     * @dev Internal function to burn a specific token.\n     * Reverts if the token does not exist.\n     * Deprecated, use _burn(uint256) instead.\n     * @param owner owner of the token to burn\n     * @param tokenId uint256 ID of the token being burned\n     */\n    function _burn(address owner, uint256 tokenId) internal {\n        super._burn(owner, tokenId);\n\n        _removeTokenFromOwnerEnumeration(owner, tokenId);\n        // Since tokenId will be deleted, we can clear its slot in _ownedTokensIndex to trigger a gas refund\n        _ownedTokensIndex[tokenId] = 0;\n\n        _removeTokenFromAllTokensEnumeration(tokenId);\n    }\n\n    /**\n     * @dev Gets the list of token IDs of the requested owner.\n     * @param owner address owning the tokens\n     * @return uint256[] List of token IDs owned by the requested address\n     */\n    function _tokensOfOwner(address owner) internal view returns (uint256[] storage) {\n        return _ownedTokens[owner];\n    }\n\n    /**\n     * @dev Private function to add a token to this extension's ownership-tracking data structures.\n     * @param to address representing the new owner of the given token ID\n     * @param tokenId uint256 ID of the token to be added to the tokens list of the given address\n     */\n    function _addTokenToOwnerEnumeration(address to, uint256 tokenId) private {\n        _ownedTokensIndex[tokenId] = _ownedTokens[to].length;\n        _ownedTokens[to].push(tokenId);\n    }\n\n    /**\n     * @dev Private function to add a token to this extension's token tracking data structures.\n     * @param tokenId uint256 ID of the token to be added to the tokens list\n     */\n    function _addTokenToAllTokensEnumeration(uint256 tokenId) private {\n        _allTokensIndex[tokenId] = _allTokens.length;\n        _allTokens.push(tokenId);\n    }\n\n    /**\n     * @dev Private function to remove a token from this extension's ownership-tracking data structures. Note that\n     * while the token is not assigned a new owner, the _ownedTokensIndex mapping is _not_ updated: this allows for\n     * gas optimizations e.g. when performing a transfer operation (avoiding double writes).\n     * This has O(1) time complexity, but alters the order of the _ownedTokens array.\n     * @param from address representing the previous owner of the given token ID\n     * @param tokenId uint256 ID of the token to be removed from the tokens list of the given address\n     */\n    function _removeTokenFromOwnerEnumeration(address from, uint256 tokenId) private {\n        // To prevent a gap in from's tokens array, we store the last token in the index of the token to delete, and\n        // then delete the last slot (swap and pop).\n\n        uint256 lastTokenIndex = _ownedTokens[from].length.sub(1);\n        uint256 tokenIndex = _ownedTokensIndex[tokenId];\n\n        // When the token to delete is the last token, the swap operation is unnecessary\n        if (tokenIndex != lastTokenIndex) {\n            uint256 lastTokenId = _ownedTokens[from][lastTokenIndex];\n\n            _ownedTokens[from][tokenIndex] = lastTokenId; // Move the last token to the slot of the to-delete token\n            _ownedTokensIndex[lastTokenId] = tokenIndex; // Update the moved token's index\n        }\n\n        // This also deletes the contents at the last position of the array\n        _ownedTokens[from].length--;\n\n        // Note that _ownedTokensIndex[tokenId] hasn't been cleared: it still points to the old slot (now occupied by\n        // lastTokenId, or just over the end of the array if the token was the last one).\n    }\n\n    /**\n     * @dev Private function to remove a token from this extension's token tracking data structures.\n     * This has O(1) time complexity, but alters the order of the _allTokens array.\n     * @param tokenId uint256 ID of the token to be removed from the tokens list\n     */\n    function _removeTokenFromAllTokensEnumeration(uint256 tokenId) private {\n        // To prevent a gap in the tokens array, we store the last token in the index of the token to delete, and\n        // then delete the last slot (swap and pop).\n\n        uint256 lastTokenIndex = _allTokens.length.sub(1);\n        uint256 tokenIndex = _allTokensIndex[tokenId];\n\n        // When the token to delete is the last token, the swap operation is unnecessary. However, since this occurs so\n        // rarely (when the last minted token is burnt) that we still do the swap here to avoid the gas cost of adding\n        // an 'if' statement (like in _removeTokenFromOwnerEnumeration)\n        uint256 lastTokenId = _allTokens[lastTokenIndex];\n\n        _allTokens[tokenIndex] = lastTokenId; // Move the last token to the slot of the to-delete token\n        _allTokensIndex[lastTokenId] = tokenIndex; // Update the moved token's index\n\n        // This also deletes the contents at the last position of the array\n        _allTokens.length--;\n        _allTokensIndex[tokenId] = 0;\n    }\n}\n\n// File: @openzeppelin/contracts/token/ERC721/IERC721Metadata.sol\n\npragma solidity ^0.5.0;\n\n\n/**\n * @title ERC-721 Non-Fungible Token Standard, optional metadata extension\n * @dev See https://eips.ethereum.org/EIPS/eip-721\n */\ncontract IERC721Metadata is IERC721 {\n    function name() external view returns (string memory);\n    function symbol() external view returns (string memory);\n    function tokenURI(uint256 tokenId) external view returns (string memory);\n}\n\n// File: @openzeppelin/contracts/token/ERC721/ERC721Metadata.sol\n\npragma solidity ^0.5.0;\n\n\n\n\ncontract ERC721Metadata is ERC165, ERC721, IERC721Metadata {\n    // Token name\n    string private _name;\n\n    // Token symbol\n    string private _symbol;\n\n    // Optional mapping for token URIs\n    mapping(uint256 => string) private _tokenURIs;\n\n    /*\n     *     bytes4(keccak256('name()')) == 0x06fdde03\n     *     bytes4(keccak256('symbol()')) == 0x95d89b41\n     *     bytes4(keccak256('tokenURI(uint256)')) == 0xc87b56dd\n     *\n     *     => 0x06fdde03 ^ 0x95d89b41 ^ 0xc87b56dd == 0x5b5e139f\n     */\n    bytes4 private constant _INTERFACE_ID_ERC721_METADATA = 0x5b5e139f;\n\n    /**\n     * @dev Constructor function\n     */\n    constructor (string memory name, string memory symbol) public {\n        _name = name;\n        _symbol = symbol;\n\n        // register the supported interfaces to conform to ERC721 via ERC165\n        _registerInterface(_INTERFACE_ID_ERC721_METADATA);\n    }\n\n    /**\n     * @dev Gets the token name.\n     * @return string representing the token name\n     */\n    function name() external view returns (string memory) {\n        return _name;\n    }\n\n    /**\n     * @dev Gets the token symbol.\n     * @return string representing the token symbol\n     */\n    function symbol() external view returns (string memory) {\n        return _symbol;\n    }\n\n    /**\n     * @dev Returns an URI for a given token ID.\n     * Throws if the token ID does not exist. May return an empty string.\n     * @param tokenId uint256 ID of the token to query\n     */\n    function tokenURI(uint256 tokenId) external view returns (string memory) {\n        require(_exists(tokenId), \"ERC721Metadata: URI query for nonexistent token\");\n        return _tokenURIs[tokenId];\n    }\n\n    /**\n     * @dev Internal function to set the token URI for a given token.\n     * Reverts if the token ID does not exist.\n     * @param tokenId uint256 ID of the token to set its URI\n     * @param uri string URI to assign\n     */\n    function _setTokenURI(uint256 tokenId, string memory uri) internal {\n        require(_exists(tokenId), \"ERC721Metadata: URI set of nonexistent token\");\n        _tokenURIs[tokenId] = uri;\n    }\n\n    /**\n     * @dev Internal function to burn a specific token.\n     * Reverts if the token does not exist.\n     * Deprecated, use _burn(uint256) instead.\n     * @param owner owner of the token to burn\n     * @param tokenId uint256 ID of the token being burned by the msg.sender\n     */\n    function _burn(address owner, uint256 tokenId) internal {\n        super._burn(owner, tokenId);\n\n        // Clear metadata (if any)\n        if (bytes(_tokenURIs[tokenId]).length != 0) {\n            delete _tokenURIs[tokenId];\n        }\n    }\n}\n\n// File: @openzeppelin/contracts/token/ERC721/ERC721Full.sol\n\npragma solidity ^0.5.0;\n\n\n\n\n/**\n * @title Full ERC721 Token\n * This implementation includes all the required and some optional functionality of the ERC721 standard\n * Moreover, it includes approve all functionality using operator terminology\n * @dev see https://eips.ethereum.org/EIPS/eip-721\n */\ncontract ERC721Full is ERC721, ERC721Enumerable, ERC721Metadata {\n    constructor (string memory name, string memory symbol) public ERC721Metadata(name, symbol) {\n        // solhint-disable-previous-line no-empty-blocks\n    }\n}\n",
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+    "exportedSymbols": {
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+                        },
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+                        }
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+                          "typeString": "bytes memory"
+                        }
+                      }
+                    ],
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+                          "typeIdentifier": "t_address_payable",
+                          "typeString": "address payable"
+                        },
+                        {
+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
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+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        },
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+                          "typeIdentifier": "t_bytes_memory_ptr",
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+                        }
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+                              "typeIdentifier": "t_address",
+                              "typeString": "address"
+                            }
+                          ],
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+                          "name": "IERC721Receiver",
+                          "nodeType": "Identifier",
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+                          "referencedDeclaration": 139,
+                          "src": "23593:15:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_type$_t_contract$_IERC721Receiver_$139_$",
+                            "typeString": "type(contract IERC721Receiver)"
+                          }
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+                          "typeIdentifier": "t_contract$_IERC721Receiver_$139",
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+                    }
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+                            "typeString": "bytes4"
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+                          "src": "23691:16:1",
+                          "typeDescriptions": {
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+                            "typeString": "bytes4"
+                          }
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+                }
+              ]
+            },
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+                    "typeString": "bool"
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+                }
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+                        "src": "23940:15:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_mapping$_t_uint256_$_t_address_$",
+                          "typeString": "mapping(uint256 => address)"
+                        }
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+                        "name": "tokenId",
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+                        "src": "23956:7:1",
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+                        "typeString": "address payable"
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+                              "nodeType": "Identifier",
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+                              "src": "23994:15:1",
+                              "typeDescriptions": {
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+                              "typeString": "address"
+                            }
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+                            "arguments": [
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+                                "hexValue": "30",
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+                                "kind": "number",
+                                "lValueRequested": false,
+                                "nodeType": "Literal",
+                                "src": "24029:1:1",
+                                "subdenomination": null,
+                                "typeDescriptions": {
+                                  "typeIdentifier": "t_rational_0_by_1",
+                                  "typeString": "int_const 0"
+                                },
+                                "value": "0"
+                              }
+                            ],
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+                                {
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+                                }
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+                              "isConstant": false,
+                              "isLValue": false,
+                              "isPure": true,
+                              "lValueRequested": false,
+                              "nodeType": "ElementaryTypeNameExpression",
+                              "src": "24021:7:1",
+                              "typeDescriptions": {
+                                "typeIdentifier": "t_type$_t_address_$",
+                                "typeString": "type(address)"
+                              },
+                              "typeName": "address"
+                            },
+                            "id": 937,
+                            "isConstant": false,
+                            "isLValue": false,
+                            "isPure": true,
+                            "kind": "typeConversion",
+                            "lValueRequested": false,
+                            "names": [],
+                            "nodeType": "FunctionCall",
+                            "src": "24021:10:1",
+                            "typeDescriptions": {
+                              "typeIdentifier": "t_address_payable",
+                              "typeString": "address payable"
+                            }
+                          },
+                          "src": "23994:37:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_address",
+                            "typeString": "address"
+                          }
+                        },
+                        "id": 939,
+                        "nodeType": "ExpressionStatement",
+                        "src": "23994:37:1"
+                      }
+                    ]
+                  }
+                }
+              ]
+            },
+            "documentation": "@dev Private function to clear current approval of a given token ID.\n@param tokenId uint256 ID of the token to be transferred",
+            "id": 943,
+            "implemented": true,
+            "kind": "function",
+            "modifiers": [],
+            "name": "_clearApproval",
+            "nodeType": "FunctionDefinition",
+            "parameters": {
+              "id": 923,
+              "nodeType": "ParameterList",
+              "parameters": [
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+                  "scope": 943,
+                  "src": "23901:15:1",
+                  "stateVariable": false,
+                  "storageLocation": "default",
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+                  "nodeType": "ExpressionStatement",
+                  "src": "28903:30:1"
+                },
+                {
+                  "expression": {
+                    "argumentTypes": null,
+                    "arguments": [
+                      {
+                        "argumentTypes": null,
+                        "id": 1135,
+                        "name": "tokenId",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 1113,
+                        "src": "28981:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      }
+                    ],
+                    "expression": {
+                      "argumentTypes": [
+                        {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      ],
+                      "id": 1134,
+                      "name": "_removeTokenFromAllTokensEnumeration",
+                      "nodeType": "Identifier",
+                      "overloadedDeclarations": [],
+                      "referencedDeclaration": 1301,
+                      "src": "28944:36:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_function_internal_nonpayable$_t_uint256_$returns$__$",
+                        "typeString": "function (uint256)"
+                      }
+                    },
+                    "id": 1136,
+                    "isConstant": false,
+                    "isLValue": false,
+                    "isPure": false,
+                    "kind": "functionCall",
+                    "lValueRequested": false,
+                    "names": [],
+                    "nodeType": "FunctionCall",
+                    "src": "28944:45:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_tuple$__$",
+                      "typeString": "tuple()"
+                    }
+                  },
+                  "id": 1137,
+                  "nodeType": "ExpressionStatement",
+                  "src": "28944:45:1"
+                }
+              ]
+            },
+            "documentation": "@dev Internal function to burn a specific token.\nReverts if the token does not exist.\nDeprecated, use _burn(uint256) instead.\n@param owner owner of the token to burn\n@param tokenId uint256 ID of the token being burned",
+            "id": 1139,
+            "implemented": true,
+            "kind": "function",
+            "modifiers": [],
+            "name": "_burn",
+            "nodeType": "FunctionDefinition",
+            "parameters": {
+              "id": 1114,
+              "nodeType": "ParameterList",
+              "parameters": [
+                {
+                  "constant": false,
+                  "id": 1111,
+                  "name": "owner",
+                  "nodeType": "VariableDeclaration",
+                  "scope": 1139,
+                  "src": "28647:13:1",
+                  "stateVariable": false,
+                  "storageLocation": "default",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_address",
+                    "typeString": "address"
+                  },
+                  "typeName": {
+                    "id": 1110,
+                    "name": "address",
+                    "nodeType": "ElementaryTypeName",
+                    "src": "28647:7:1",
+                    "stateMutability": "nonpayable",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_address",
+                      "typeString": "address"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                },
+                {
+                  "constant": false,
+                  "id": 1113,
+                  "name": "tokenId",
+                  "nodeType": "VariableDeclaration",
+                  "scope": 1139,
+                  "src": "28662:15:1",
+                  "stateVariable": false,
+                  "storageLocation": "default",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_uint256",
+                    "typeString": "uint256"
+                  },
+                  "typeName": {
+                    "id": 1112,
+                    "name": "uint256",
+                    "nodeType": "ElementaryTypeName",
+                    "src": "28662:7:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_uint256",
+                      "typeString": "uint256"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                }
+              ],
+              "src": "28646:32:1"
+            },
+            "returnParameters": {
+              "id": 1115,
+              "nodeType": "ParameterList",
+              "parameters": [],
+              "src": "28688:0:1"
+            },
+            "scope": 1302,
+            "src": "28632:364:1",
+            "stateMutability": "nonpayable",
+            "superFunction": 811,
+            "visibility": "internal"
+          },
+          {
+            "body": {
+              "id": 1151,
+              "nodeType": "Block",
+              "src": "29282:43:1",
+              "statements": [
+                {
+                  "expression": {
+                    "argumentTypes": null,
+                    "baseExpression": {
+                      "argumentTypes": null,
+                      "id": 1147,
+                      "name": "_ownedTokens",
+                      "nodeType": "Identifier",
+                      "overloadedDeclarations": [],
+                      "referencedDeclaration": 981,
+                      "src": "29299:12:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_mapping$_t_address_$_t_array$_t_uint256_$dyn_storage_$",
+                        "typeString": "mapping(address => uint256[] storage ref)"
+                      }
+                    },
+                    "id": 1149,
+                    "indexExpression": {
+                      "argumentTypes": null,
+                      "id": 1148,
+                      "name": "owner",
+                      "nodeType": "Identifier",
+                      "overloadedDeclarations": [],
+                      "referencedDeclaration": 1141,
+                      "src": "29312:5:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_address",
+                        "typeString": "address"
+                      }
+                    },
+                    "isConstant": false,
+                    "isLValue": true,
+                    "isPure": false,
+                    "lValueRequested": false,
+                    "nodeType": "IndexAccess",
+                    "src": "29299:19:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_array$_t_uint256_$dyn_storage",
+                      "typeString": "uint256[] storage ref"
+                    }
+                  },
+                  "functionReturnParameters": 1146,
+                  "id": 1150,
+                  "nodeType": "Return",
+                  "src": "29292:26:1"
+                }
+              ]
+            },
+            "documentation": "@dev Gets the list of token IDs of the requested owner.\n@param owner address owning the tokens\n@return uint256[] List of token IDs owned by the requested address",
+            "id": 1152,
+            "implemented": true,
+            "kind": "function",
+            "modifiers": [],
+            "name": "_tokensOfOwner",
+            "nodeType": "FunctionDefinition",
+            "parameters": {
+              "id": 1142,
+              "nodeType": "ParameterList",
+              "parameters": [
+                {
+                  "constant": false,
+                  "id": 1141,
+                  "name": "owner",
+                  "nodeType": "VariableDeclaration",
+                  "scope": 1152,
+                  "src": "29225:13:1",
+                  "stateVariable": false,
+                  "storageLocation": "default",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_address",
+                    "typeString": "address"
+                  },
+                  "typeName": {
+                    "id": 1140,
+                    "name": "address",
+                    "nodeType": "ElementaryTypeName",
+                    "src": "29225:7:1",
+                    "stateMutability": "nonpayable",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_address",
+                      "typeString": "address"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                }
+              ],
+              "src": "29224:15:1"
+            },
+            "returnParameters": {
+              "id": 1146,
+              "nodeType": "ParameterList",
+              "parameters": [
+                {
+                  "constant": false,
+                  "id": 1145,
+                  "name": "",
+                  "nodeType": "VariableDeclaration",
+                  "scope": 1152,
+                  "src": "29263:17:1",
+                  "stateVariable": false,
+                  "storageLocation": "storage",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_array$_t_uint256_$dyn_storage_ptr",
+                    "typeString": "uint256[]"
+                  },
+                  "typeName": {
+                    "baseType": {
+                      "id": 1143,
+                      "name": "uint256",
+                      "nodeType": "ElementaryTypeName",
+                      "src": "29263:7:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_uint256",
+                        "typeString": "uint256"
+                      }
+                    },
+                    "id": 1144,
+                    "length": null,
+                    "nodeType": "ArrayTypeName",
+                    "src": "29263:9:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_array$_t_uint256_$dyn_storage_ptr",
+                      "typeString": "uint256[]"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                }
+              ],
+              "src": "29262:19:1"
+            },
+            "scope": 1302,
+            "src": "29201:124:1",
+            "stateMutability": "view",
+            "superFunction": null,
+            "visibility": "internal"
+          },
+          {
+            "body": {
+              "id": 1175,
+              "nodeType": "Block",
+              "src": "29693:109:1",
+              "statements": [
+                {
+                  "expression": {
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+                    "id": 1166,
+                    "isConstant": false,
+                    "isLValue": false,
+                    "isPure": false,
+                    "lValueRequested": false,
+                    "leftHandSide": {
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+                      "baseExpression": {
+                        "argumentTypes": null,
+                        "id": 1159,
+                        "name": "_ownedTokensIndex",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 985,
+                        "src": "29703:17:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_mapping$_t_uint256_$_t_uint256_$",
+                          "typeString": "mapping(uint256 => uint256)"
+                        }
+                      },
+                      "id": 1161,
+                      "indexExpression": {
+                        "argumentTypes": null,
+                        "id": 1160,
+                        "name": "tokenId",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 1156,
+                        "src": "29721:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      },
+                      "isConstant": false,
+                      "isLValue": true,
+                      "isPure": false,
+                      "lValueRequested": true,
+                      "nodeType": "IndexAccess",
+                      "src": "29703:26:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_uint256",
+                        "typeString": "uint256"
+                      }
+                    },
+                    "nodeType": "Assignment",
+                    "operator": "=",
+                    "rightHandSide": {
+                      "argumentTypes": null,
+                      "expression": {
+                        "argumentTypes": null,
+                        "baseExpression": {
+                          "argumentTypes": null,
+                          "id": 1162,
+                          "name": "_ownedTokens",
+                          "nodeType": "Identifier",
+                          "overloadedDeclarations": [],
+                          "referencedDeclaration": 981,
+                          "src": "29732:12:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_mapping$_t_address_$_t_array$_t_uint256_$dyn_storage_$",
+                            "typeString": "mapping(address => uint256[] storage ref)"
+                          }
+                        },
+                        "id": 1164,
+                        "indexExpression": {
+                          "argumentTypes": null,
+                          "id": 1163,
+                          "name": "to",
+                          "nodeType": "Identifier",
+                          "overloadedDeclarations": [],
+                          "referencedDeclaration": 1154,
+                          "src": "29745:2:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_address",
+                            "typeString": "address"
+                          }
+                        },
+                        "isConstant": false,
+                        "isLValue": true,
+                        "isPure": false,
+                        "lValueRequested": false,
+                        "nodeType": "IndexAccess",
+                        "src": "29732:16:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_array$_t_uint256_$dyn_storage",
+                          "typeString": "uint256[] storage ref"
+                        }
+                      },
+                      "id": 1165,
+                      "isConstant": false,
+                      "isLValue": true,
+                      "isPure": false,
+                      "lValueRequested": false,
+                      "memberName": "length",
+                      "nodeType": "MemberAccess",
+                      "referencedDeclaration": null,
+                      "src": "29732:23:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_uint256",
+                        "typeString": "uint256"
+                      }
+                    },
+                    "src": "29703:52:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_uint256",
+                      "typeString": "uint256"
+                    }
+                  },
+                  "id": 1167,
+                  "nodeType": "ExpressionStatement",
+                  "src": "29703:52:1"
+                },
+                {
+                  "expression": {
+                    "argumentTypes": null,
+                    "arguments": [
+                      {
+                        "argumentTypes": null,
+                        "id": 1172,
+                        "name": "tokenId",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 1156,
+                        "src": "29787:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      }
+                    ],
+                    "expression": {
+                      "argumentTypes": [
+                        {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      ],
+                      "expression": {
+                        "argumentTypes": null,
+                        "baseExpression": {
+                          "argumentTypes": null,
+                          "id": 1168,
+                          "name": "_ownedTokens",
+                          "nodeType": "Identifier",
+                          "overloadedDeclarations": [],
+                          "referencedDeclaration": 981,
+                          "src": "29765:12:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_mapping$_t_address_$_t_array$_t_uint256_$dyn_storage_$",
+                            "typeString": "mapping(address => uint256[] storage ref)"
+                          }
+                        },
+                        "id": 1170,
+                        "indexExpression": {
+                          "argumentTypes": null,
+                          "id": 1169,
+                          "name": "to",
+                          "nodeType": "Identifier",
+                          "overloadedDeclarations": [],
+                          "referencedDeclaration": 1154,
+                          "src": "29778:2:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_address",
+                            "typeString": "address"
+                          }
+                        },
+                        "isConstant": false,
+                        "isLValue": true,
+                        "isPure": false,
+                        "lValueRequested": false,
+                        "nodeType": "IndexAccess",
+                        "src": "29765:16:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_array$_t_uint256_$dyn_storage",
+                          "typeString": "uint256[] storage ref"
+                        }
+                      },
+                      "id": 1171,
+                      "isConstant": false,
+                      "isLValue": false,
+                      "isPure": false,
+                      "lValueRequested": false,
+                      "memberName": "push",
+                      "nodeType": "MemberAccess",
+                      "referencedDeclaration": null,
+                      "src": "29765:21:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_function_arraypush_nonpayable$_t_uint256_$returns$_t_uint256_$",
+                        "typeString": "function (uint256) returns (uint256)"
+                      }
+                    },
+                    "id": 1173,
+                    "isConstant": false,
+                    "isLValue": false,
+                    "isPure": false,
+                    "kind": "functionCall",
+                    "lValueRequested": false,
+                    "names": [],
+                    "nodeType": "FunctionCall",
+                    "src": "29765:30:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_uint256",
+                      "typeString": "uint256"
+                    }
+                  },
+                  "id": 1174,
+                  "nodeType": "ExpressionStatement",
+                  "src": "29765:30:1"
+                }
+              ]
+            },
+            "documentation": "@dev Private function to add a token to this extension's ownership-tracking data structures.\n@param to address representing the new owner of the given token ID\n@param tokenId uint256 ID of the token to be added to the tokens list of the given address",
+            "id": 1176,
+            "implemented": true,
+            "kind": "function",
+            "modifiers": [],
+            "name": "_addTokenToOwnerEnumeration",
+            "nodeType": "FunctionDefinition",
+            "parameters": {
+              "id": 1157,
+              "nodeType": "ParameterList",
+              "parameters": [
+                {
+                  "constant": false,
+                  "id": 1154,
+                  "name": "to",
+                  "nodeType": "VariableDeclaration",
+                  "scope": 1176,
+                  "src": "29656:10:1",
+                  "stateVariable": false,
+                  "storageLocation": "default",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_address",
+                    "typeString": "address"
+                  },
+                  "typeName": {
+                    "id": 1153,
+                    "name": "address",
+                    "nodeType": "ElementaryTypeName",
+                    "src": "29656:7:1",
+                    "stateMutability": "nonpayable",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_address",
+                      "typeString": "address"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                },
+                {
+                  "constant": false,
+                  "id": 1156,
+                  "name": "tokenId",
+                  "nodeType": "VariableDeclaration",
+                  "scope": 1176,
+                  "src": "29668:15:1",
+                  "stateVariable": false,
+                  "storageLocation": "default",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_uint256",
+                    "typeString": "uint256"
+                  },
+                  "typeName": {
+                    "id": 1155,
+                    "name": "uint256",
+                    "nodeType": "ElementaryTypeName",
+                    "src": "29668:7:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_uint256",
+                      "typeString": "uint256"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                }
+              ],
+              "src": "29655:29:1"
+            },
+            "returnParameters": {
+              "id": 1158,
+              "nodeType": "ParameterList",
+              "parameters": [],
+              "src": "29693:0:1"
+            },
+            "scope": 1302,
+            "src": "29619:183:1",
+            "stateMutability": "nonpayable",
+            "superFunction": null,
+            "visibility": "private"
+          },
+          {
+            "body": {
+              "id": 1194,
+              "nodeType": "Block",
+              "src": "30063:95:1",
+              "statements": [
+                {
+                  "expression": {
+                    "argumentTypes": null,
+                    "id": 1186,
+                    "isConstant": false,
+                    "isLValue": false,
+                    "isPure": false,
+                    "lValueRequested": false,
+                    "leftHandSide": {
+                      "argumentTypes": null,
+                      "baseExpression": {
+                        "argumentTypes": null,
+                        "id": 1181,
+                        "name": "_allTokensIndex",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 992,
+                        "src": "30073:15:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_mapping$_t_uint256_$_t_uint256_$",
+                          "typeString": "mapping(uint256 => uint256)"
+                        }
+                      },
+                      "id": 1183,
+                      "indexExpression": {
+                        "argumentTypes": null,
+                        "id": 1182,
+                        "name": "tokenId",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 1178,
+                        "src": "30089:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      },
+                      "isConstant": false,
+                      "isLValue": true,
+                      "isPure": false,
+                      "lValueRequested": true,
+                      "nodeType": "IndexAccess",
+                      "src": "30073:24:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_uint256",
+                        "typeString": "uint256"
+                      }
+                    },
+                    "nodeType": "Assignment",
+                    "operator": "=",
+                    "rightHandSide": {
+                      "argumentTypes": null,
+                      "expression": {
+                        "argumentTypes": null,
+                        "id": 1184,
+                        "name": "_allTokens",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 988,
+                        "src": "30100:10:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_array$_t_uint256_$dyn_storage",
+                          "typeString": "uint256[] storage ref"
+                        }
+                      },
+                      "id": 1185,
+                      "isConstant": false,
+                      "isLValue": true,
+                      "isPure": false,
+                      "lValueRequested": false,
+                      "memberName": "length",
+                      "nodeType": "MemberAccess",
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+                      "src": "30100:17:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_uint256",
+                        "typeString": "uint256"
+                      }
+                    },
+                    "src": "30073:44:1",
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+                      "typeIdentifier": "t_uint256",
+                      "typeString": "uint256"
+                    }
+                  },
+                  "id": 1187,
+                  "nodeType": "ExpressionStatement",
+                  "src": "30073:44:1"
+                },
+                {
+                  "expression": {
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+                    "arguments": [
+                      {
+                        "argumentTypes": null,
+                        "id": 1191,
+                        "name": "tokenId",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 1178,
+                        "src": "30143:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      }
+                    ],
+                    "expression": {
+                      "argumentTypes": [
+                        {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      ],
+                      "expression": {
+                        "argumentTypes": null,
+                        "id": 1188,
+                        "name": "_allTokens",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 988,
+                        "src": "30127:10:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_array$_t_uint256_$dyn_storage",
+                          "typeString": "uint256[] storage ref"
+                        }
+                      },
+                      "id": 1190,
+                      "isConstant": false,
+                      "isLValue": false,
+                      "isPure": false,
+                      "lValueRequested": false,
+                      "memberName": "push",
+                      "nodeType": "MemberAccess",
+                      "referencedDeclaration": null,
+                      "src": "30127:15:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_function_arraypush_nonpayable$_t_uint256_$returns$_t_uint256_$",
+                        "typeString": "function (uint256) returns (uint256)"
+                      }
+                    },
+                    "id": 1192,
+                    "isConstant": false,
+                    "isLValue": false,
+                    "isPure": false,
+                    "kind": "functionCall",
+                    "lValueRequested": false,
+                    "names": [],
+                    "nodeType": "FunctionCall",
+                    "src": "30127:24:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_uint256",
+                      "typeString": "uint256"
+                    }
+                  },
+                  "id": 1193,
+                  "nodeType": "ExpressionStatement",
+                  "src": "30127:24:1"
+                }
+              ]
+            },
+            "documentation": "@dev Private function to add a token to this extension's token tracking data structures.\n@param tokenId uint256 ID of the token to be added to the tokens list",
+            "id": 1195,
+            "implemented": true,
+            "kind": "function",
+            "modifiers": [],
+            "name": "_addTokenToAllTokensEnumeration",
+            "nodeType": "FunctionDefinition",
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+                        },
+                        "value": "1"
+                      }
+                    ],
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+                            "src": "31060:12:1",
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+                              "typeIdentifier": "t_mapping$_t_address_$_t_array$_t_uint256_$dyn_storage_$",
+                              "typeString": "mapping(address => uint256[] storage ref)"
+                            }
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+                              "typeIdentifier": "t_address",
+                              "typeString": "address"
+                            }
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+                        }
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+                      "src": "31060:29:1",
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+                        "typeIdentifier": "t_function_internal_pure$_t_uint256_$_t_uint256_$returns$_t_uint256_$bound_to$_t_uint256_$",
+                        "typeString": "function (uint256,uint256) pure returns (uint256)"
+                      }
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+                    "src": "31060:32:1",
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+                      "typeString": "uint256"
+                    }
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+                },
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+                      "typeDescriptions": {
+                        "typeIdentifier": "t_uint256",
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+                      },
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+                        "name": "uint256",
+                        "nodeType": "ElementaryTypeName",
+                        "src": "31102:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
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+                        "typeIdentifier": "t_mapping$_t_uint256_$_t_uint256_$",
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+                      }
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+                      "typeString": "uint256"
+                    }
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+                },
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+                      "src": "31253:10:1",
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+                        "typeIdentifier": "t_uint256",
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+                      }
+                    },
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+                      "name": "lastTokenIndex",
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+                      "src": "31267:14:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_uint256",
+                        "typeString": "uint256"
+                      }
+                    },
+                    "src": "31253:28:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_bool",
+                      "typeString": "bool"
+                    }
+                  },
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+                  "src": "31249:323:1",
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+                    "statements": [
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+                        ],
+                        "declarations": [
+                          {
+                            "constant": false,
+                            "id": 1222,
+                            "name": "lastTokenId",
+                            "nodeType": "VariableDeclaration",
+                            "scope": 1243,
+                            "src": "31297:19:1",
+                            "stateVariable": false,
+                            "storageLocation": "default",
+                            "typeDescriptions": {
+                              "typeIdentifier": "t_uint256",
+                              "typeString": "uint256"
+                            },
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+                              "name": "uint256",
+                              "nodeType": "ElementaryTypeName",
+                              "src": "31297:7:1",
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+                                "typeIdentifier": "t_uint256",
+                                "typeString": "uint256"
+                              }
+                            },
+                            "value": null,
+                            "visibility": "internal"
+                          }
+                        ],
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+                        "initialValue": {
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+                          "baseExpression": {
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+                              "id": 1223,
+                              "name": "_ownedTokens",
+                              "nodeType": "Identifier",
+                              "overloadedDeclarations": [],
+                              "referencedDeclaration": 981,
+                              "src": "31319:12:1",
+                              "typeDescriptions": {
+                                "typeIdentifier": "t_mapping$_t_address_$_t_array$_t_uint256_$dyn_storage_$",
+                                "typeString": "mapping(address => uint256[] storage ref)"
+                              }
+                            },
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+                              "name": "from",
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+                              "referencedDeclaration": 1197,
+                              "src": "31332:4:1",
+                              "typeDescriptions": {
+                                "typeIdentifier": "t_address",
+                                "typeString": "address"
+                              }
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+                              "typeIdentifier": "t_array$_t_uint256_$dyn_storage",
+                              "typeString": "uint256[] storage ref"
+                            }
+                          },
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+                            "name": "lastTokenIndex",
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+                            "src": "31338:14:1",
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+                              "typeIdentifier": "t_uint256",
+                              "typeString": "uint256"
+                            }
+                          },
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+                          "nodeType": "IndexAccess",
+                          "src": "31319:34:1",
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+                            "typeIdentifier": "t_uint256",
+                            "typeString": "uint256"
+                          }
+                        },
+                        "nodeType": "VariableDeclarationStatement",
+                        "src": "31297:56:1"
+                      },
+                      {
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+                              "baseExpression": {
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+                                "name": "_ownedTokens",
+                                "nodeType": "Identifier",
+                                "overloadedDeclarations": [],
+                                "referencedDeclaration": 981,
+                                "src": "31368:12:1",
+                                "typeDescriptions": {
+                                  "typeIdentifier": "t_mapping$_t_address_$_t_array$_t_uint256_$dyn_storage_$",
+                                  "typeString": "mapping(address => uint256[] storage ref)"
+                                }
+                              },
+                              "id": 1232,
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+                                "argumentTypes": null,
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+                                "name": "from",
+                                "nodeType": "Identifier",
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+                                "referencedDeclaration": 1197,
+                                "src": "31381:4:1",
+                                "typeDescriptions": {
+                                  "typeIdentifier": "t_address",
+                                  "typeString": "address"
+                                }
+                              },
+                              "isConstant": false,
+                              "isLValue": true,
+                              "isPure": false,
+                              "lValueRequested": false,
+                              "nodeType": "IndexAccess",
+                              "src": "31368:18:1",
+                              "typeDescriptions": {
+                                "typeIdentifier": "t_array$_t_uint256_$dyn_storage",
+                                "typeString": "uint256[] storage ref"
+                              }
+                            },
+                            "id": 1233,
+                            "indexExpression": {
+                              "argumentTypes": null,
+                              "id": 1231,
+                              "name": "tokenIndex",
+                              "nodeType": "Identifier",
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+                              "referencedDeclaration": 1213,
+                              "src": "31387:10:1",
+                              "typeDescriptions": {
+                                "typeIdentifier": "t_uint256",
+                                "typeString": "uint256"
+                              }
+                            },
+                            "isConstant": false,
+                            "isLValue": true,
+                            "isPure": false,
+                            "lValueRequested": true,
+                            "nodeType": "IndexAccess",
+                            "src": "31368:30:1",
+                            "typeDescriptions": {
+                              "typeIdentifier": "t_uint256",
+                              "typeString": "uint256"
+                            }
+                          },
+                          "nodeType": "Assignment",
+                          "operator": "=",
+                          "rightHandSide": {
+                            "argumentTypes": null,
+                            "id": 1234,
+                            "name": "lastTokenId",
+                            "nodeType": "Identifier",
+                            "overloadedDeclarations": [],
+                            "referencedDeclaration": 1222,
+                            "src": "31401:11:1",
+                            "typeDescriptions": {
+                              "typeIdentifier": "t_uint256",
+                              "typeString": "uint256"
+                            }
+                          },
+                          "src": "31368:44:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_uint256",
+                            "typeString": "uint256"
+                          }
+                        },
+                        "id": 1236,
+                        "nodeType": "ExpressionStatement",
+                        "src": "31368:44:1"
+                      },
+                      {
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+                          "id": 1241,
+                          "isConstant": false,
+                          "isLValue": false,
+                          "isPure": false,
+                          "lValueRequested": false,
+                          "leftHandSide": {
+                            "argumentTypes": null,
+                            "baseExpression": {
+                              "argumentTypes": null,
+                              "id": 1237,
+                              "name": "_ownedTokensIndex",
+                              "nodeType": "Identifier",
+                              "overloadedDeclarations": [],
+                              "referencedDeclaration": 985,
+                              "src": "31484:17:1",
+                              "typeDescriptions": {
+                                "typeIdentifier": "t_mapping$_t_uint256_$_t_uint256_$",
+                                "typeString": "mapping(uint256 => uint256)"
+                              }
+                            },
+                            "id": 1239,
+                            "indexExpression": {
+                              "argumentTypes": null,
+                              "id": 1238,
+                              "name": "lastTokenId",
+                              "nodeType": "Identifier",
+                              "overloadedDeclarations": [],
+                              "referencedDeclaration": 1222,
+                              "src": "31502:11:1",
+                              "typeDescriptions": {
+                                "typeIdentifier": "t_uint256",
+                                "typeString": "uint256"
+                              }
+                            },
+                            "isConstant": false,
+                            "isLValue": true,
+                            "isPure": false,
+                            "lValueRequested": true,
+                            "nodeType": "IndexAccess",
+                            "src": "31484:30:1",
+                            "typeDescriptions": {
+                              "typeIdentifier": "t_uint256",
+                              "typeString": "uint256"
+                            }
+                          },
+                          "nodeType": "Assignment",
+                          "operator": "=",
+                          "rightHandSide": {
+                            "argumentTypes": null,
+                            "id": 1240,
+                            "name": "tokenIndex",
+                            "nodeType": "Identifier",
+                            "overloadedDeclarations": [],
+                            "referencedDeclaration": 1213,
+                            "src": "31517:10:1",
+                            "typeDescriptions": {
+                              "typeIdentifier": "t_uint256",
+                              "typeString": "uint256"
+                            }
+                          },
+                          "src": "31484:43:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_uint256",
+                            "typeString": "uint256"
+                          }
+                        },
+                        "id": 1242,
+                        "nodeType": "ExpressionStatement",
+                        "src": "31484:43:1"
+                      }
+                    ]
+                  }
+                },
+                {
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+                    "id": 1249,
+                    "isConstant": false,
+                    "isLValue": false,
+                    "isPure": false,
+                    "lValueRequested": false,
+                    "nodeType": "UnaryOperation",
+                    "operator": "--",
+                    "prefix": false,
+                    "src": "31658:27:1",
+                    "subExpression": {
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+                      "expression": {
+                        "argumentTypes": null,
+                        "baseExpression": {
+                          "argumentTypes": null,
+                          "id": 1245,
+                          "name": "_ownedTokens",
+                          "nodeType": "Identifier",
+                          "overloadedDeclarations": [],
+                          "referencedDeclaration": 981,
+                          "src": "31658:12:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_mapping$_t_address_$_t_array$_t_uint256_$dyn_storage_$",
+                            "typeString": "mapping(address => uint256[] storage ref)"
+                          }
+                        },
+                        "id": 1247,
+                        "indexExpression": {
+                          "argumentTypes": null,
+                          "id": 1246,
+                          "name": "from",
+                          "nodeType": "Identifier",
+                          "overloadedDeclarations": [],
+                          "referencedDeclaration": 1197,
+                          "src": "31671:4:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_address",
+                            "typeString": "address"
+                          }
+                        },
+                        "isConstant": false,
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+                        "isPure": false,
+                        "lValueRequested": false,
+                        "nodeType": "IndexAccess",
+                        "src": "31658:18:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_array$_t_uint256_$dyn_storage",
+                          "typeString": "uint256[] storage ref"
+                        }
+                      },
+                      "id": 1248,
+                      "isConstant": false,
+                      "isLValue": true,
+                      "isPure": false,
+                      "lValueRequested": true,
+                      "memberName": "length",
+                      "nodeType": "MemberAccess",
+                      "referencedDeclaration": null,
+                      "src": "31658:25:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_uint256",
+                        "typeString": "uint256"
+                      }
+                    },
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_uint256",
+                      "typeString": "uint256"
+                    }
+                  },
+                  "id": 1250,
+                  "nodeType": "ExpressionStatement",
+                  "src": "31658:27:1"
+                }
+              ]
+            },
+            "documentation": "@dev Private function to remove a token from this extension's ownership-tracking data structures. Note that\nwhile the token is not assigned a new owner, the _ownedTokensIndex mapping is _not_ updated: this allows for\ngas optimizations e.g. when performing a transfer operation (avoiding double writes).\nThis has O(1) time complexity, but alters the order of the _ownedTokens array.\n@param from address representing the previous owner of the given token ID\n@param tokenId uint256 ID of the token to be removed from the tokens list of the given address",
+            "id": 1252,
+            "implemented": true,
+            "kind": "function",
+            "modifiers": [],
+            "name": "_removeTokenFromOwnerEnumeration",
+            "nodeType": "FunctionDefinition",
+            "parameters": {
+              "id": 1200,
+              "nodeType": "ParameterList",
+              "parameters": [
+                {
+                  "constant": false,
+                  "id": 1197,
+                  "name": "from",
+                  "nodeType": "VariableDeclaration",
+                  "scope": 1252,
+                  "src": "30815:12:1",
+                  "stateVariable": false,
+                  "storageLocation": "default",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_address",
+                    "typeString": "address"
+                  },
+                  "typeName": {
+                    "id": 1196,
+                    "name": "address",
+                    "nodeType": "ElementaryTypeName",
+                    "src": "30815:7:1",
+                    "stateMutability": "nonpayable",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_address",
+                      "typeString": "address"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                },
+                {
+                  "constant": false,
+                  "id": 1199,
+                  "name": "tokenId",
+                  "nodeType": "VariableDeclaration",
+                  "scope": 1252,
+                  "src": "30829:15:1",
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+                        }
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+                        {
+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        },
+                        {
+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        },
+                        {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
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+                }
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+                          "src": "23514:2:1",
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+                          "name": "msg",
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+                            "typeString": "msg"
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+                        "src": "23630:10:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_address_payable",
+                          "typeString": "address payable"
+                        }
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+                        "name": "from",
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+                        "src": "23642:4:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        }
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+                        "name": "tokenId",
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+                        "src": "23648:7:1",
+                        "typeDescriptions": {
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+                          "typeString": "uint256"
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+                        "typeDescriptions": {
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+                          "typeString": "bytes memory"
+                        }
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+                    ],
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+                          "typeIdentifier": "t_address_payable",
+                          "typeString": "address payable"
+                        },
+                        {
+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        },
+                        {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        },
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+                          "name": "IERC721Receiver",
+                          "nodeType": "Identifier",
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+                          "src": "23593:15:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_type$_t_contract$_IERC721Receiver_$139_$",
+                            "typeString": "type(contract IERC721Receiver)"
+                          }
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+                          "src": "23681:6:1",
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+                            "typeIdentifier": "t_bytes4",
+                            "typeString": "bytes4"
+                          }
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+                        "nodeType": "BinaryOperation",
+                        "operator": "==",
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+                          "argumentTypes": null,
+                          "id": 915,
+                          "name": "_ERC721_RECEIVED",
+                          "nodeType": "Identifier",
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+                          "referencedDeclaration": 403,
+                          "src": "23691:16:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_bytes4",
+                            "typeString": "bytes4"
+                          }
+                        },
+                        "src": "23681:26:1",
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+                          "typeIdentifier": "t_bool",
+                          "typeString": "bool"
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+                  "id": 918,
+                  "nodeType": "Return",
+                  "src": "23673:35:1"
+                }
+              ]
+            },
+            "documentation": "@dev Internal function to invoke `onERC721Received` on a target address.\nThe call is not executed if the target address is not a contract.\n     * This function is deprecated.\n@param from address representing the previous owner of the given token ID\n@param to target address that will receive the tokens\n@param tokenId uint256 ID of the token to be transferred\n@param _data bytes optional data to send along with the call\n@return bool whether the call correctly returned the expected magic value",
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+                  "storageLocation": "default",
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+                    "nodeType": "ElementaryTypeName",
+                    "src": "23400:7:1",
+                    "stateMutability": "nonpayable",
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+                  "visibility": "internal"
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+                  "src": "23414:10:1",
+                  "stateVariable": false,
+                  "storageLocation": "default",
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+                    "typeIdentifier": "t_address",
+                    "typeString": "address"
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+                    "name": "address",
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+                  "value": null,
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+                },
+                {
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+                  "id": 886,
+                  "name": "tokenId",
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+                            ],
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+                            "src": "27187:11:1",
+                            "typeDescriptions": {
+                              "typeIdentifier": "t_function_internal_view$__$returns$_t_uint256_$",
+                              "typeString": "function () view returns (uint256)"
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+                        "kind": "string",
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+                        "nodeType": "Literal",
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+                        "typeDescriptions": {
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+                          "typeIdentifier": "t_bool",
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+                        1544
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+                      "id": 1052,
+                      "name": "_allTokens",
+                      "nodeType": "Identifier",
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+                      "referencedDeclaration": 988,
+                      "src": "27266:10:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_array$_t_uint256_$dyn_storage",
+                        "typeString": "uint256[] storage ref"
+                      }
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+                      "src": "27277:5:1",
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+                        "src": "27770:4:1",
+                        "typeDescriptions": {
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+                          "typeString": "address"
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+                        "name": "to",
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+                        "src": "27776:2:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
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+                        "id": 1071,
+                        "name": "tokenId",
+                        "nodeType": "Identifier",
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+                        "referencedDeclaration": 1063,
+                        "src": "27780:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      }
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+                          "typeString": "address"
+                        },
+                        {
+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        },
+                        {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
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+                        "name": "super",
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+                        "src": "27750:5:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_super$_ERC721Enumerable_$1302",
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+                        }
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+                        "src": "27832:4:1",
+                        "typeDescriptions": {
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+                          "typeString": "address"
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+                        "id": 1076,
+                        "name": "tokenId",
+                        "nodeType": "Identifier",
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+                        "src": "27838:7:1",
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+                          "typeString": "address"
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+                        {
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+                          "typeString": "uint256"
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+                        "name": "to",
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+                        "src": "27885:2:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        }
+                      },
+                      {
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+                        "name": "tokenId",
+                        "nodeType": "Identifier",
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+                        "referencedDeclaration": 1063,
+                        "src": "27889:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
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+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        },
+                        {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
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+                      "name": "_addTokenToOwnerEnumeration",
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+                      "src": "27857:27:1",
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+                    "stateMutability": "nonpayable",
+                    "typeDescriptions": {
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+                      "typeString": "address"
+                    }
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+                        "src": "28236:2:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
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+                        "typeDescriptions": {
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+                        "name": "tokenId",
+                        "nodeType": "Identifier",
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+                        "src": "28342:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
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+                      "argumentTypes": [
+                        {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
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+                      "name": "_addTokenToAllTokensEnumeration",
+                      "nodeType": "Identifier",
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+                      "src": "28310:31:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_function_internal_nonpayable$_t_uint256_$returns$__$",
+                        "typeString": "function (uint256)"
+                      }
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+                    "nodeType": "FunctionCall",
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+                  "id": 1107,
+                  "nodeType": "ExpressionStatement",
+                  "src": "28310:40:1"
+                }
+              ]
+            },
+            "documentation": "@dev Internal function to mint a new token.\nReverts if the given token ID already exists.\n@param to address the beneficiary that will own the minted token\n@param tokenId uint256 ID of the token to be minted",
+            "id": 1109,
+            "implemented": true,
+            "kind": "function",
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+            "name": "_mint",
+            "nodeType": "FunctionDefinition",
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+              "nodeType": "ParameterList",
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+                  "id": 1087,
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+                  "stateVariable": false,
+                  "storageLocation": "default",
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+                    "typeIdentifier": "t_address",
+                    "typeString": "address"
+                  },
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+                    "name": "address",
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+                    "src": "28176:7:1",
+                    "stateMutability": "nonpayable",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_address",
+                      "typeString": "address"
+                    }
+                  },
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+                  "visibility": "internal"
+                },
+                {
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+                  "id": 1089,
+                  "name": "tokenId",
+                  "nodeType": "VariableDeclaration",
+                  "scope": 1109,
+                  "src": "28188:15:1",
+                  "stateVariable": false,
+                  "storageLocation": "default",
+                  "typeDescriptions": {
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+                    "typeString": "uint256"
+                  },
+                  "typeName": {
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+                    "name": "uint256",
+                    "nodeType": "ElementaryTypeName",
+                    "src": "28188:7:1",
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+                      "typeIdentifier": "t_uint256",
+                      "typeString": "uint256"
+                    }
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+                  "value": null,
+                  "visibility": "internal"
+                }
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+              "src": "28175:29:1"
+            },
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+            "src": "28161:196:1",
+            "stateMutability": "nonpayable",
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+            "visibility": "internal"
+          },
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+              "nodeType": "Block",
+              "src": "28688:308:1",
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+                    "arguments": [
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+                        "name": "owner",
+                        "nodeType": "Identifier",
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+                        "referencedDeclaration": 1111,
+                        "src": "28710:5:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        }
+                      },
+                      {
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+                        "id": 1120,
+                        "name": "tokenId",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 1113,
+                        "src": "28717:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      }
+                    ],
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+                      "argumentTypes": [
+                        {
+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        },
+                        {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      ],
+                      "expression": {
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+                        "id": 1116,
+                        "name": "super",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 1572,
+                        "src": "28698:5:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_super$_ERC721Enumerable_$1302",
+                          "typeString": "contract super ERC721Enumerable"
+                        }
+                      },
+                      "id": 1118,
+                      "isConstant": false,
+                      "isLValue": false,
+                      "isPure": false,
+                      "lValueRequested": false,
+                      "memberName": "_burn",
+                      "nodeType": "MemberAccess",
+                      "referencedDeclaration": 811,
+                      "src": "28698:11:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_function_internal_nonpayable$_t_address_$_t_uint256_$returns$__$",
+                        "typeString": "function (address,uint256)"
+                      }
+                    },
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+                    "isConstant": false,
+                    "isLValue": false,
+                    "isPure": false,
+                    "kind": "functionCall",
+                    "lValueRequested": false,
+                    "names": [],
+                    "nodeType": "FunctionCall",
+                    "src": "28698:27:1",
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+                      "typeString": "tuple()"
+                    }
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+                },
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+                    "arguments": [
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+                        "id": 1124,
+                        "name": "owner",
+                        "nodeType": "Identifier",
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+                        "referencedDeclaration": 1111,
+                        "src": "28769:5:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        }
+                      },
+                      {
+                        "argumentTypes": null,
+                        "id": 1125,
+                        "name": "tokenId",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 1113,
+                        "src": "28776:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      }
+                    ],
+                    "expression": {
+                      "argumentTypes": [
+                        {
+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        },
+                        {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      ],
+                      "id": 1123,
+                      "name": "_removeTokenFromOwnerEnumeration",
+                      "nodeType": "Identifier",
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+                      "referencedDeclaration": 1252,
+                      "src": "28736:32:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_function_internal_nonpayable$_t_address_$_t_uint256_$returns$__$",
+                        "typeString": "function (address,uint256)"
+                      }
+                    },
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+                    "isConstant": false,
+                    "isLValue": false,
+                    "isPure": false,
+                    "kind": "functionCall",
+                    "lValueRequested": false,
+                    "names": [],
+                    "nodeType": "FunctionCall",
+                    "src": "28736:48:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_tuple$__$",
+                      "typeString": "tuple()"
+                    }
+                  },
+                  "id": 1127,
+                  "nodeType": "ExpressionStatement",
+                  "src": "28736:48:1"
+                },
+                {
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+                    "isLValue": false,
+                    "isPure": false,
+                    "lValueRequested": false,
+                    "leftHandSide": {
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+                      "baseExpression": {
+                        "argumentTypes": null,
+                        "id": 1128,
+                        "name": "_ownedTokensIndex",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 985,
+                        "src": "28903:17:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_mapping$_t_uint256_$_t_uint256_$",
+                          "typeString": "mapping(uint256 => uint256)"
+                        }
+                      },
+                      "id": 1130,
+                      "indexExpression": {
+                        "argumentTypes": null,
+                        "id": 1129,
+                        "name": "tokenId",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 1113,
+                        "src": "28921:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      },
+                      "isConstant": false,
+                      "isLValue": true,
+                      "isPure": false,
+                      "lValueRequested": true,
+                      "nodeType": "IndexAccess",
+                      "src": "28903:26:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_uint256",
+                        "typeString": "uint256"
+                      }
+                    },
+                    "nodeType": "Assignment",
+                    "operator": "=",
+                    "rightHandSide": {
+                      "argumentTypes": null,
+                      "hexValue": "30",
+                      "id": 1131,
+                      "isConstant": false,
+                      "isLValue": false,
+                      "isPure": true,
+                      "kind": "number",
+                      "lValueRequested": false,
+                      "nodeType": "Literal",
+                      "src": "28932:1:1",
+                      "subdenomination": null,
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_rational_0_by_1",
+                        "typeString": "int_const 0"
+                      },
+                      "value": "0"
+                    },
+                    "src": "28903:30:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_uint256",
+                      "typeString": "uint256"
+                    }
+                  },
+                  "id": 1133,
+                  "nodeType": "ExpressionStatement",
+                  "src": "28903:30:1"
+                },
+                {
+                  "expression": {
+                    "argumentTypes": null,
+                    "arguments": [
+                      {
+                        "argumentTypes": null,
+                        "id": 1135,
+                        "name": "tokenId",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 1113,
+                        "src": "28981:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      }
+                    ],
+                    "expression": {
+                      "argumentTypes": [
+                        {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      ],
+                      "id": 1134,
+                      "name": "_removeTokenFromAllTokensEnumeration",
+                      "nodeType": "Identifier",
+                      "overloadedDeclarations": [],
+                      "referencedDeclaration": 1301,
+                      "src": "28944:36:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_function_internal_nonpayable$_t_uint256_$returns$__$",
+                        "typeString": "function (uint256)"
+                      }
+                    },
+                    "id": 1136,
+                    "isConstant": false,
+                    "isLValue": false,
+                    "isPure": false,
+                    "kind": "functionCall",
+                    "lValueRequested": false,
+                    "names": [],
+                    "nodeType": "FunctionCall",
+                    "src": "28944:45:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_tuple$__$",
+                      "typeString": "tuple()"
+                    }
+                  },
+                  "id": 1137,
+                  "nodeType": "ExpressionStatement",
+                  "src": "28944:45:1"
+                }
+              ]
+            },
+            "documentation": "@dev Internal function to burn a specific token.\nReverts if the token does not exist.\nDeprecated, use _burn(uint256) instead.\n@param owner owner of the token to burn\n@param tokenId uint256 ID of the token being burned",
+            "id": 1139,
+            "implemented": true,
+            "kind": "function",
+            "modifiers": [],
+            "name": "_burn",
+            "nodeType": "FunctionDefinition",
+            "parameters": {
+              "id": 1114,
+              "nodeType": "ParameterList",
+              "parameters": [
+                {
+                  "constant": false,
+                  "id": 1111,
+                  "name": "owner",
+                  "nodeType": "VariableDeclaration",
+                  "scope": 1139,
+                  "src": "28647:13:1",
+                  "stateVariable": false,
+                  "storageLocation": "default",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_address",
+                    "typeString": "address"
+                  },
+                  "typeName": {
+                    "id": 1110,
+                    "name": "address",
+                    "nodeType": "ElementaryTypeName",
+                    "src": "28647:7:1",
+                    "stateMutability": "nonpayable",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_address",
+                      "typeString": "address"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                },
+                {
+                  "constant": false,
+                  "id": 1113,
+                  "name": "tokenId",
+                  "nodeType": "VariableDeclaration",
+                  "scope": 1139,
+                  "src": "28662:15:1",
+                  "stateVariable": false,
+                  "storageLocation": "default",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_uint256",
+                    "typeString": "uint256"
+                  },
+                  "typeName": {
+                    "id": 1112,
+                    "name": "uint256",
+                    "nodeType": "ElementaryTypeName",
+                    "src": "28662:7:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_uint256",
+                      "typeString": "uint256"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                }
+              ],
+              "src": "28646:32:1"
+            },
+            "returnParameters": {
+              "id": 1115,
+              "nodeType": "ParameterList",
+              "parameters": [],
+              "src": "28688:0:1"
+            },
+            "scope": 1302,
+            "src": "28632:364:1",
+            "stateMutability": "nonpayable",
+            "superFunction": 811,
+            "visibility": "internal"
+          },
+          {
+            "body": {
+              "id": 1151,
+              "nodeType": "Block",
+              "src": "29282:43:1",
+              "statements": [
+                {
+                  "expression": {
+                    "argumentTypes": null,
+                    "baseExpression": {
+                      "argumentTypes": null,
+                      "id": 1147,
+                      "name": "_ownedTokens",
+                      "nodeType": "Identifier",
+                      "overloadedDeclarations": [],
+                      "referencedDeclaration": 981,
+                      "src": "29299:12:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_mapping$_t_address_$_t_array$_t_uint256_$dyn_storage_$",
+                        "typeString": "mapping(address => uint256[] storage ref)"
+                      }
+                    },
+                    "id": 1149,
+                    "indexExpression": {
+                      "argumentTypes": null,
+                      "id": 1148,
+                      "name": "owner",
+                      "nodeType": "Identifier",
+                      "overloadedDeclarations": [],
+                      "referencedDeclaration": 1141,
+                      "src": "29312:5:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_address",
+                        "typeString": "address"
+                      }
+                    },
+                    "isConstant": false,
+                    "isLValue": true,
+                    "isPure": false,
+                    "lValueRequested": false,
+                    "nodeType": "IndexAccess",
+                    "src": "29299:19:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_array$_t_uint256_$dyn_storage",
+                      "typeString": "uint256[] storage ref"
+                    }
+                  },
+                  "functionReturnParameters": 1146,
+                  "id": 1150,
+                  "nodeType": "Return",
+                  "src": "29292:26:1"
+                }
+              ]
+            },
+            "documentation": "@dev Gets the list of token IDs of the requested owner.\n@param owner address owning the tokens\n@return uint256[] List of token IDs owned by the requested address",
+            "id": 1152,
+            "implemented": true,
+            "kind": "function",
+            "modifiers": [],
+            "name": "_tokensOfOwner",
+            "nodeType": "FunctionDefinition",
+            "parameters": {
+              "id": 1142,
+              "nodeType": "ParameterList",
+              "parameters": [
+                {
+                  "constant": false,
+                  "id": 1141,
+                  "name": "owner",
+                  "nodeType": "VariableDeclaration",
+                  "scope": 1152,
+                  "src": "29225:13:1",
+                  "stateVariable": false,
+                  "storageLocation": "default",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_address",
+                    "typeString": "address"
+                  },
+                  "typeName": {
+                    "id": 1140,
+                    "name": "address",
+                    "nodeType": "ElementaryTypeName",
+                    "src": "29225:7:1",
+                    "stateMutability": "nonpayable",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_address",
+                      "typeString": "address"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                }
+              ],
+              "src": "29224:15:1"
+            },
+            "returnParameters": {
+              "id": 1146,
+              "nodeType": "ParameterList",
+              "parameters": [
+                {
+                  "constant": false,
+                  "id": 1145,
+                  "name": "",
+                  "nodeType": "VariableDeclaration",
+                  "scope": 1152,
+                  "src": "29263:17:1",
+                  "stateVariable": false,
+                  "storageLocation": "storage",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_array$_t_uint256_$dyn_storage_ptr",
+                    "typeString": "uint256[]"
+                  },
+                  "typeName": {
+                    "baseType": {
+                      "id": 1143,
+                      "name": "uint256",
+                      "nodeType": "ElementaryTypeName",
+                      "src": "29263:7:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_uint256",
+                        "typeString": "uint256"
+                      }
+                    },
+                    "id": 1144,
+                    "length": null,
+                    "nodeType": "ArrayTypeName",
+                    "src": "29263:9:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_array$_t_uint256_$dyn_storage_ptr",
+                      "typeString": "uint256[]"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                }
+              ],
+              "src": "29262:19:1"
+            },
+            "scope": 1302,
+            "src": "29201:124:1",
+            "stateMutability": "view",
+            "superFunction": null,
+            "visibility": "internal"
+          },
+          {
+            "body": {
+              "id": 1175,
+              "nodeType": "Block",
+              "src": "29693:109:1",
+              "statements": [
+                {
+                  "expression": {
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+                    "id": 1166,
+                    "isConstant": false,
+                    "isLValue": false,
+                    "isPure": false,
+                    "lValueRequested": false,
+                    "leftHandSide": {
+                      "argumentTypes": null,
+                      "baseExpression": {
+                        "argumentTypes": null,
+                        "id": 1159,
+                        "name": "_ownedTokensIndex",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 985,
+                        "src": "29703:17:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_mapping$_t_uint256_$_t_uint256_$",
+                          "typeString": "mapping(uint256 => uint256)"
+                        }
+                      },
+                      "id": 1161,
+                      "indexExpression": {
+                        "argumentTypes": null,
+                        "id": 1160,
+                        "name": "tokenId",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 1156,
+                        "src": "29721:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      },
+                      "isConstant": false,
+                      "isLValue": true,
+                      "isPure": false,
+                      "lValueRequested": true,
+                      "nodeType": "IndexAccess",
+                      "src": "29703:26:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_uint256",
+                        "typeString": "uint256"
+                      }
+                    },
+                    "nodeType": "Assignment",
+                    "operator": "=",
+                    "rightHandSide": {
+                      "argumentTypes": null,
+                      "expression": {
+                        "argumentTypes": null,
+                        "baseExpression": {
+                          "argumentTypes": null,
+                          "id": 1162,
+                          "name": "_ownedTokens",
+                          "nodeType": "Identifier",
+                          "overloadedDeclarations": [],
+                          "referencedDeclaration": 981,
+                          "src": "29732:12:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_mapping$_t_address_$_t_array$_t_uint256_$dyn_storage_$",
+                            "typeString": "mapping(address => uint256[] storage ref)"
+                          }
+                        },
+                        "id": 1164,
+                        "indexExpression": {
+                          "argumentTypes": null,
+                          "id": 1163,
+                          "name": "to",
+                          "nodeType": "Identifier",
+                          "overloadedDeclarations": [],
+                          "referencedDeclaration": 1154,
+                          "src": "29745:2:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_address",
+                            "typeString": "address"
+                          }
+                        },
+                        "isConstant": false,
+                        "isLValue": true,
+                        "isPure": false,
+                        "lValueRequested": false,
+                        "nodeType": "IndexAccess",
+                        "src": "29732:16:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_array$_t_uint256_$dyn_storage",
+                          "typeString": "uint256[] storage ref"
+                        }
+                      },
+                      "id": 1165,
+                      "isConstant": false,
+                      "isLValue": true,
+                      "isPure": false,
+                      "lValueRequested": false,
+                      "memberName": "length",
+                      "nodeType": "MemberAccess",
+                      "referencedDeclaration": null,
+                      "src": "29732:23:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_uint256",
+                        "typeString": "uint256"
+                      }
+                    },
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+                            "nodeType": "IndexAccess",
+                            "src": "31319:18:1",
+                            "typeDescriptions": {
+                              "typeIdentifier": "t_array$_t_uint256_$dyn_storage",
+                              "typeString": "uint256[] storage ref"
+                            }
+                          },
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+                          "indexExpression": {
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+                            "name": "lastTokenIndex",
+                            "nodeType": "Identifier",
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+                            "src": "31338:14:1",
+                            "typeDescriptions": {
+                              "typeIdentifier": "t_uint256",
+                              "typeString": "uint256"
+                            }
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+                          "isPure": false,
+                          "lValueRequested": false,
+                          "nodeType": "IndexAccess",
+                          "src": "31319:34:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_uint256",
+                            "typeString": "uint256"
+                          }
+                        },
+                        "nodeType": "VariableDeclarationStatement",
+                        "src": "31297:56:1"
+                      },
+                      {
+                        "expression": {
+                          "argumentTypes": null,
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+                          "isLValue": false,
+                          "isPure": false,
+                          "lValueRequested": false,
+                          "leftHandSide": {
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+                            "baseExpression": {
+                              "argumentTypes": null,
+                              "baseExpression": {
+                                "argumentTypes": null,
+                                "id": 1229,
+                                "name": "_ownedTokens",
+                                "nodeType": "Identifier",
+                                "overloadedDeclarations": [],
+                                "referencedDeclaration": 981,
+                                "src": "31368:12:1",
+                                "typeDescriptions": {
+                                  "typeIdentifier": "t_mapping$_t_address_$_t_array$_t_uint256_$dyn_storage_$",
+                                  "typeString": "mapping(address => uint256[] storage ref)"
+                                }
+                              },
+                              "id": 1232,
+                              "indexExpression": {
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+                                "name": "from",
+                                "nodeType": "Identifier",
+                                "overloadedDeclarations": [],
+                                "referencedDeclaration": 1197,
+                                "src": "31381:4:1",
+                                "typeDescriptions": {
+                                  "typeIdentifier": "t_address",
+                                  "typeString": "address"
+                                }
+                              },
+                              "isConstant": false,
+                              "isLValue": true,
+                              "isPure": false,
+                              "lValueRequested": false,
+                              "nodeType": "IndexAccess",
+                              "src": "31368:18:1",
+                              "typeDescriptions": {
+                                "typeIdentifier": "t_array$_t_uint256_$dyn_storage",
+                                "typeString": "uint256[] storage ref"
+                              }
+                            },
+                            "id": 1233,
+                            "indexExpression": {
+                              "argumentTypes": null,
+                              "id": 1231,
+                              "name": "tokenIndex",
+                              "nodeType": "Identifier",
+                              "overloadedDeclarations": [],
+                              "referencedDeclaration": 1213,
+                              "src": "31387:10:1",
+                              "typeDescriptions": {
+                                "typeIdentifier": "t_uint256",
+                                "typeString": "uint256"
+                              }
+                            },
+                            "isConstant": false,
+                            "isLValue": true,
+                            "isPure": false,
+                            "lValueRequested": true,
+                            "nodeType": "IndexAccess",
+                            "src": "31368:30:1",
+                            "typeDescriptions": {
+                              "typeIdentifier": "t_uint256",
+                              "typeString": "uint256"
+                            }
+                          },
+                          "nodeType": "Assignment",
+                          "operator": "=",
+                          "rightHandSide": {
+                            "argumentTypes": null,
+                            "id": 1234,
+                            "name": "lastTokenId",
+                            "nodeType": "Identifier",
+                            "overloadedDeclarations": [],
+                            "referencedDeclaration": 1222,
+                            "src": "31401:11:1",
+                            "typeDescriptions": {
+                              "typeIdentifier": "t_uint256",
+                              "typeString": "uint256"
+                            }
+                          },
+                          "src": "31368:44:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_uint256",
+                            "typeString": "uint256"
+                          }
+                        },
+                        "id": 1236,
+                        "nodeType": "ExpressionStatement",
+                        "src": "31368:44:1"
+                      },
+                      {
+                        "expression": {
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+                          "id": 1241,
+                          "isConstant": false,
+                          "isLValue": false,
+                          "isPure": false,
+                          "lValueRequested": false,
+                          "leftHandSide": {
+                            "argumentTypes": null,
+                            "baseExpression": {
+                              "argumentTypes": null,
+                              "id": 1237,
+                              "name": "_ownedTokensIndex",
+                              "nodeType": "Identifier",
+                              "overloadedDeclarations": [],
+                              "referencedDeclaration": 985,
+                              "src": "31484:17:1",
+                              "typeDescriptions": {
+                                "typeIdentifier": "t_mapping$_t_uint256_$_t_uint256_$",
+                                "typeString": "mapping(uint256 => uint256)"
+                              }
+                            },
+                            "id": 1239,
+                            "indexExpression": {
+                              "argumentTypes": null,
+                              "id": 1238,
+                              "name": "lastTokenId",
+                              "nodeType": "Identifier",
+                              "overloadedDeclarations": [],
+                              "referencedDeclaration": 1222,
+                              "src": "31502:11:1",
+                              "typeDescriptions": {
+                                "typeIdentifier": "t_uint256",
+                                "typeString": "uint256"
+                              }
+                            },
+                            "isConstant": false,
+                            "isLValue": true,
+                            "isPure": false,
+                            "lValueRequested": true,
+                            "nodeType": "IndexAccess",
+                            "src": "31484:30:1",
+                            "typeDescriptions": {
+                              "typeIdentifier": "t_uint256",
+                              "typeString": "uint256"
+                            }
+                          },
+                          "nodeType": "Assignment",
+                          "operator": "=",
+                          "rightHandSide": {
+                            "argumentTypes": null,
+                            "id": 1240,
+                            "name": "tokenIndex",
+                            "nodeType": "Identifier",
+                            "overloadedDeclarations": [],
+                            "referencedDeclaration": 1213,
+                            "src": "31517:10:1",
+                            "typeDescriptions": {
+                              "typeIdentifier": "t_uint256",
+                              "typeString": "uint256"
+                            }
+                          },
+                          "src": "31484:43:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_uint256",
+                            "typeString": "uint256"
+                          }
+                        },
+                        "id": 1242,
+                        "nodeType": "ExpressionStatement",
+                        "src": "31484:43:1"
+                      }
+                    ]
+                  }
+                },
+                {
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+                    "id": 1249,
+                    "isConstant": false,
+                    "isLValue": false,
+                    "isPure": false,
+                    "lValueRequested": false,
+                    "nodeType": "UnaryOperation",
+                    "operator": "--",
+                    "prefix": false,
+                    "src": "31658:27:1",
+                    "subExpression": {
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+                      "expression": {
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+                        "baseExpression": {
+                          "argumentTypes": null,
+                          "id": 1245,
+                          "name": "_ownedTokens",
+                          "nodeType": "Identifier",
+                          "overloadedDeclarations": [],
+                          "referencedDeclaration": 981,
+                          "src": "31658:12:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_mapping$_t_address_$_t_array$_t_uint256_$dyn_storage_$",
+                            "typeString": "mapping(address => uint256[] storage ref)"
+                          }
+                        },
+                        "id": 1247,
+                        "indexExpression": {
+                          "argumentTypes": null,
+                          "id": 1246,
+                          "name": "from",
+                          "nodeType": "Identifier",
+                          "overloadedDeclarations": [],
+                          "referencedDeclaration": 1197,
+                          "src": "31671:4:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_address",
+                            "typeString": "address"
+                          }
+                        },
+                        "isConstant": false,
+                        "isLValue": true,
+                        "isPure": false,
+                        "lValueRequested": false,
+                        "nodeType": "IndexAccess",
+                        "src": "31658:18:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_array$_t_uint256_$dyn_storage",
+                          "typeString": "uint256[] storage ref"
+                        }
+                      },
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+                      "isConstant": false,
+                      "isLValue": true,
+                      "isPure": false,
+                      "lValueRequested": true,
+                      "memberName": "length",
+                      "nodeType": "MemberAccess",
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+                      "src": "31658:25:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_uint256",
+                        "typeString": "uint256"
+                      }
+                    },
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+                      "typeIdentifier": "t_uint256",
+                      "typeString": "uint256"
+                    }
+                  },
+                  "id": 1250,
+                  "nodeType": "ExpressionStatement",
+                  "src": "31658:27:1"
+                }
+              ]
+            },
+            "documentation": "@dev Private function to remove a token from this extension's ownership-tracking data structures. Note that\nwhile the token is not assigned a new owner, the _ownedTokensIndex mapping is _not_ updated: this allows for\ngas optimizations e.g. when performing a transfer operation (avoiding double writes).\nThis has O(1) time complexity, but alters the order of the _ownedTokens array.\n@param from address representing the previous owner of the given token ID\n@param tokenId uint256 ID of the token to be removed from the tokens list of the given address",
+            "id": 1252,
+            "implemented": true,
+            "kind": "function",
+            "modifiers": [],
+            "name": "_removeTokenFromOwnerEnumeration",
+            "nodeType": "FunctionDefinition",
+            "parameters": {
+              "id": 1200,
+              "nodeType": "ParameterList",
+              "parameters": [
+                {
+                  "constant": false,
+                  "id": 1197,
+                  "name": "from",
+                  "nodeType": "VariableDeclaration",
+                  "scope": 1252,
+                  "src": "30815:12:1",
+                  "stateVariable": false,
+                  "storageLocation": "default",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_address",
+                    "typeString": "address"
+                  },
+                  "typeName": {
+                    "id": 1196,
+                    "name": "address",
+                    "nodeType": "ElementaryTypeName",
+                    "src": "30815:7:1",
+                    "stateMutability": "nonpayable",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_address",
+                      "typeString": "address"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                },
+                {
+                  "constant": false,
+                  "id": 1199,
+                  "name": "tokenId",
+                  "nodeType": "VariableDeclaration",
+                  "scope": 1252,
+                  "src": "30829:15:1",
+                  "stateVariable": false,
+                  "storageLocation": "default",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_uint256",
+                    "typeString": "uint256"
+                  },
+                  "typeName": {
+                    "id": 1198,
+                    "name": "uint256",
+                    "nodeType": "ElementaryTypeName",
+                    "src": "30829:7:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_uint256",
+                      "typeString": "uint256"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                }
+              ],
+              "src": "30814:31:1"
+            },
+            "returnParameters": {
+              "id": 1201,
+              "nodeType": "ParameterList",
+              "parameters": [],
+              "src": "30854:0:1"
+            },
+            "scope": 1302,
+            "src": "30773:1128:1",
+            "stateMutability": "nonpayable",
+            "superFunction": null,
+            "visibility": "private"
+          },
+          {
+            "body": {
+              "id": 1300,
+              "nodeType": "Block",
+              "src": "32260:993:1",
+              "statements": [
+                {
+                  "assignments": [
+                    1258
+                  ],
+                  "declarations": [
+                    {
+                      "constant": false,
+                      "id": 1258,
+                      "name": "lastTokenIndex",
+                      "nodeType": "VariableDeclaration",
+                      "scope": 1300,
+                      "src": "32438:22:1",
+                      "stateVariable": false,
+                      "storageLocation": "default",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_uint256",
+                        "typeString": "uint256"
+                      },
+                      "typeName": {
+                        "id": 1257,
+                        "name": "uint256",
+                        "nodeType": "ElementaryTypeName",
+                        "src": "32438:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      },
+                      "value": null,
+                      "visibility": "internal"
+                    }
+                  ],
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+                  "initialValue": {
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+                    "arguments": [
+                      {
+                        "argumentTypes": null,
+                        "hexValue": "31",
+                        "id": 1262,
+                        "isConstant": false,
+                        "isLValue": false,
+                        "isPure": true,
+                        "kind": "number",
+                        "lValueRequested": false,
+                        "nodeType": "Literal",
+                        "src": "32485:1:1",
+                        "subdenomination": null,
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_rational_1_by_1",
+                          "typeString": "int_const 1"
+                        },
+                        "value": "1"
+                      }
+                    ],
+                    "expression": {
+                      "argumentTypes": [
+                        {
+                          "typeIdentifier": "t_rational_1_by_1",
+                          "typeString": "int_const 1"
+                        }
+                      ],
+                      "expression": {
+                        "argumentTypes": null,
+                        "expression": {
+                          "argumentTypes": null,
+                          "id": 1259,
+                          "name": "_allTokens",
+                          "nodeType": "Identifier",
+                          "overloadedDeclarations": [],
+                          "referencedDeclaration": 988,
+                          "src": "32463:10:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_array$_t_uint256_$dyn_storage",
+                            "typeString": "uint256[] storage ref"
+                          }
+                        },
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+                        "isConstant": false,
+                        "isLValue": true,
+                        "isPure": false,
+                        "lValueRequested": false,
+                        "memberName": "length",
+                        "nodeType": "MemberAccess",
+                        "referencedDeclaration": null,
+                        "src": "32463:17:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
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+                      "isConstant": false,
+                      "isLValue": false,
+                      "isPure": false,
+                      "lValueRequested": false,
+                      "memberName": "sub",
+                      "nodeType": "MemberAccess",
+                      "referencedDeclaration": 190,
+                      "src": "32463:21:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_function_internal_pure$_t_uint256_$_t_uint256_$returns$_t_uint256_$bound_to$_t_uint256_$",
+                        "typeString": "function (uint256,uint256) pure returns (uint256)"
+                      }
+                    },
+                    "id": 1263,
+                    "isConstant": false,
+                    "isLValue": false,
+                    "isPure": false,
+                    "kind": "functionCall",
+                    "lValueRequested": false,
+                    "names": [],
+                    "nodeType": "FunctionCall",
+                    "src": "32463:24:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_uint256",
+                      "typeString": "uint256"
+                    }
+                  },
+                  "nodeType": "VariableDeclarationStatement",
+                  "src": "32438:49:1"
+                },
+                {
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+                    1266
+                  ],
+                  "declarations": [
+                    {
+                      "constant": false,
+                      "id": 1266,
+                      "name": "tokenIndex",
+                      "nodeType": "VariableDeclaration",
+                      "scope": 1300,
+                      "src": "32497:18:1",
+                      "stateVariable": false,
+                      "storageLocation": "default",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_uint256",
+                        "typeString": "uint256"
+                      },
+                      "typeName": {
+                        "id": 1265,
+                        "name": "uint256",
+                        "nodeType": "ElementaryTypeName",
+                        "src": "32497:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      },
+                      "value": null,
+                      "visibility": "internal"
+                    }
+                  ],
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+                  "initialValue": {
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+                    "baseExpression": {
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+                      "id": 1267,
+                      "name": "_allTokensIndex",
+                      "nodeType": "Identifier",
+                      "overloadedDeclarations": [],
+                      "referencedDeclaration": 992,
+                      "src": "32518:15:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_mapping$_t_uint256_$_t_uint256_$",
+                        "typeString": "mapping(uint256 => uint256)"
+                      }
+                    },
+                    "id": 1269,
+                    "indexExpression": {
+                      "argumentTypes": null,
+                      "id": 1268,
+                      "name": "tokenId",
+                      "nodeType": "Identifier",
+                      "overloadedDeclarations": [],
+                      "referencedDeclaration": 1254,
+                      "src": "32534:7:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_uint256",
+                        "typeString": "uint256"
+                      }
+                    },
+                    "isConstant": false,
+                    "isLValue": true,
+                    "isPure": false,
+                    "lValueRequested": false,
+                    "nodeType": "IndexAccess",
+                    "src": "32518:24:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_uint256",
+                      "typeString": "uint256"
+                    }
+                  },
+                  "nodeType": "VariableDeclarationStatement",
+                  "src": "32497:45:1"
+                },
+                {
+                  "assignments": [
+                    1272
+                  ],
+                  "declarations": [
+                    {
+                      "constant": false,
+                      "id": 1272,
+                      "name": "lastTokenId",
+                      "nodeType": "VariableDeclaration",
+                      "scope": 1300,
+                      "src": "32864:19:1",
+                      "stateVariable": false,
+                      "storageLocation": "default",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_uint256",
+                        "typeString": "uint256"
+                      },
+                      "typeName": {
+                        "id": 1271,
+                        "name": "uint256",
+                        "nodeType": "ElementaryTypeName",
+                        "src": "32864:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      },
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+                      "visibility": "internal"
+                    }
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+                  "initialValue": {
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+                      "name": "_allTokens",
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+                      "src": "32886:10:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_array$_t_uint256_$dyn_storage",
+                        "typeString": "uint256[] storage ref"
+                      }
+                    },
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+                    "indexExpression": {
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+                      "id": 1274,
+                      "name": "lastTokenIndex",
+                      "nodeType": "Identifier",
+                      "overloadedDeclarations": [],
+                      "referencedDeclaration": 1258,
+                      "src": "32897:14:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_uint256",
+                        "typeString": "uint256"
+                      }
+                    },
+                    "isConstant": false,
+                    "isLValue": true,
+                    "isPure": false,
+                    "lValueRequested": false,
+                    "nodeType": "IndexAccess",
+                    "src": "32886:26:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_uint256",
+                      "typeString": "uint256"
+                    }
+                  },
+                  "nodeType": "VariableDeclarationStatement",
+                  "src": "32864:48:1"
+                },
+                {
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+                        "name": "_allTokens",
+                        "nodeType": "Identifier",
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+                        "referencedDeclaration": 988,
+                        "src": "32923:10:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_array$_t_uint256_$dyn_storage",
+                          "typeString": "uint256[] storage ref"
+                        }
+                      },
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+                      "indexExpression": {
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+                        "id": 1278,
+                        "name": "tokenIndex",
+                        "nodeType": "Identifier",
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+                        "src": "32934:10:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
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+                        "typeIdentifier": "t_uint256",
+                        "typeString": "uint256"
+                      }
+                    },
+                    "nodeType": "Assignment",
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+                      "name": "lastTokenId",
+                      "nodeType": "Identifier",
+                      "overloadedDeclarations": [],
+                      "referencedDeclaration": 1272,
+                      "src": "32948:11:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_uint256",
+                        "typeString": "uint256"
+                      }
+                    },
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+                        "name": "_allTokensIndex",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 992,
+                        "src": "33027:15:1",
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+            "id": 1417,
+            "implemented": true,
+            "kind": "function",
+            "modifiers": [],
+            "name": "_setTokenURI",
+            "nodeType": "FunctionDefinition",
+            "parameters": {
+              "id": 1401,
+              "nodeType": "ParameterList",
+              "parameters": [
+                {
+                  "constant": false,
+                  "id": 1398,
+                  "name": "tokenId",
+                  "nodeType": "VariableDeclaration",
+                  "scope": 1417,
+                  "src": "35749:15:1",
+                  "stateVariable": false,
+                  "storageLocation": "default",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_uint256",
+                    "typeString": "uint256"
+                  },
+                  "typeName": {
+                    "id": 1397,
+                    "name": "uint256",
+                    "nodeType": "ElementaryTypeName",
+                    "src": "35749:7:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_uint256",
+                      "typeString": "uint256"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                },
+                {
+                  "constant": false,
+                  "id": 1400,
+                  "name": "uri",
+                  "nodeType": "VariableDeclaration",
+                  "scope": 1417,
+                  "src": "35766:17:1",
+                  "stateVariable": false,
+                  "storageLocation": "memory",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_string_memory_ptr",
+                    "typeString": "string"
+                  },
+                  "typeName": {
+                    "id": 1399,
+                    "name": "string",
+                    "nodeType": "ElementaryTypeName",
+                    "src": "35766:6:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_string_storage_ptr",
+                      "typeString": "string"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                }
+              ],
+              "src": "35748:36:1"
+            },
+            "returnParameters": {
+              "id": 1402,
+              "nodeType": "ParameterList",
+              "parameters": [],
+              "src": "35794:0:1"
+            },
+            "scope": 1448,
+            "src": "35727:192:1",
+            "stateMutability": "nonpayable",
+            "superFunction": null,
+            "visibility": "internal"
+          },
+          {
+            "body": {
+              "id": 1446,
+              "nodeType": "Block",
+              "src": "36268:184:1",
+              "statements": [
+                {
+                  "expression": {
+                    "argumentTypes": null,
+                    "arguments": [
+                      {
+                        "argumentTypes": null,
+                        "id": 1427,
+                        "name": "owner",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 1419,
+                        "src": "36290:5:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        }
+                      },
+                      {
+                        "argumentTypes": null,
+                        "id": 1428,
+                        "name": "tokenId",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 1421,
+                        "src": "36297:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      }
+                    ],
+                    "expression": {
+                      "argumentTypes": [
+                        {
+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        },
+                        {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      ],
+                      "expression": {
+                        "argumentTypes": null,
+                        "id": 1424,
+                        "name": "super",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 1576,
+                        "src": "36278:5:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_super$_ERC721Metadata_$1448",
+                          "typeString": "contract super ERC721Metadata"
+                        }
+                      },
+                      "id": 1426,
+                      "isConstant": false,
+                      "isLValue": false,
+                      "isPure": false,
+                      "lValueRequested": false,
+                      "memberName": "_burn",
+                      "nodeType": "MemberAccess",
+                      "referencedDeclaration": 811,
+                      "src": "36278:11:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_function_internal_nonpayable$_t_address_$_t_uint256_$returns$__$",
+                        "typeString": "function (address,uint256)"
+                      }
+                    },
+                    "id": 1429,
+                    "isConstant": false,
+                    "isLValue": false,
+                    "isPure": false,
+                    "kind": "functionCall",
+                    "lValueRequested": false,
+                    "names": [],
+                    "nodeType": "FunctionCall",
+                    "src": "36278:27:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_tuple$__$",
+                      "typeString": "tuple()"
+                    }
+                  },
+                  "id": 1430,
+                  "nodeType": "ExpressionStatement",
+                  "src": "36278:27:1"
+                },
+                {
+                  "condition": {
+                    "argumentTypes": null,
+                    "commonType": {
+                      "typeIdentifier": "t_uint256",
+                      "typeString": "uint256"
+                    },
+                    "id": 1438,
+                    "isConstant": false,
+                    "isLValue": false,
+                    "isPure": false,
+                    "lValueRequested": false,
+                    "leftExpression": {
+                      "argumentTypes": null,
+                      "expression": {
+                        "argumentTypes": null,
+                        "arguments": [
+                          {
+                            "argumentTypes": null,
+                            "baseExpression": {
+                              "argumentTypes": null,
+                              "id": 1432,
+                              "name": "_tokenURIs",
+                              "nodeType": "Identifier",
+                              "overloadedDeclarations": [],
+                              "referencedDeclaration": 1338,
+                              "src": "36361:10:1",
+                              "typeDescriptions": {
+                                "typeIdentifier": "t_mapping$_t_uint256_$_t_string_storage_$",
+                                "typeString": "mapping(uint256 => string storage ref)"
+                              }
+                            },
+                            "id": 1434,
+                            "indexExpression": {
+                              "argumentTypes": null,
+                              "id": 1433,
+                              "name": "tokenId",
+                              "nodeType": "Identifier",
+                              "overloadedDeclarations": [],
+                              "referencedDeclaration": 1421,
+                              "src": "36372:7:1",
+                              "typeDescriptions": {
+                                "typeIdentifier": "t_uint256",
+                                "typeString": "uint256"
+                              }
+                            },
+                            "isConstant": false,
+                            "isLValue": true,
+                            "isPure": false,
+                            "lValueRequested": false,
+                            "nodeType": "IndexAccess",
+                            "src": "36361:19:1",
+                            "typeDescriptions": {
+                              "typeIdentifier": "t_string_storage",
+                              "typeString": "string storage ref"
+                            }
+                          }
+                        ],
+                        "expression": {
+                          "argumentTypes": [
+                            {
+                              "typeIdentifier": "t_string_storage",
+                              "typeString": "string storage ref"
+                            }
+                          ],
+                          "id": 1431,
+                          "isConstant": false,
+                          "isLValue": false,
+                          "isPure": true,
+                          "lValueRequested": false,
+                          "nodeType": "ElementaryTypeNameExpression",
+                          "src": "36355:5:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_type$_t_bytes_storage_ptr_$",
+                            "typeString": "type(bytes storage pointer)"
+                          },
+                          "typeName": "bytes"
+                        },
+                        "id": 1435,
+                        "isConstant": false,
+                        "isLValue": false,
+                        "isPure": false,
+                        "kind": "typeConversion",
+                        "lValueRequested": false,
+                        "names": [],
+                        "nodeType": "FunctionCall",
+                        "src": "36355:26:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_bytes_storage_ptr",
+                          "typeString": "bytes storage pointer"
+                        }
+                      },
+                      "id": 1436,
+                      "isConstant": false,
+                      "isLValue": true,
+                      "isPure": false,
+                      "lValueRequested": false,
+                      "memberName": "length",
+                      "nodeType": "MemberAccess",
+                      "referencedDeclaration": null,
+                      "src": "36355:33:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_uint256",
+                        "typeString": "uint256"
+                      }
+                    },
+                    "nodeType": "BinaryOperation",
+                    "operator": "!=",
+                    "rightExpression": {
+                      "argumentTypes": null,
+                      "hexValue": "30",
+                      "id": 1437,
+                      "isConstant": false,
+                      "isLValue": false,
+                      "isPure": true,
+                      "kind": "number",
+                      "lValueRequested": false,
+                      "nodeType": "Literal",
+                      "src": "36392:1:1",
+                      "subdenomination": null,
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_rational_0_by_1",
+                        "typeString": "int_const 0"
+                      },
+                      "value": "0"
+                    },
+                    "src": "36355:38:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_bool",
+                      "typeString": "bool"
+                    }
+                  },
+                  "falseBody": null,
+                  "id": 1445,
+                  "nodeType": "IfStatement",
+                  "src": "36351:95:1",
+                  "trueBody": {
+                    "id": 1444,
+                    "nodeType": "Block",
+                    "src": "36395:51:1",
+                    "statements": [
+                      {
+                        "expression": {
+                          "argumentTypes": null,
+                          "id": 1442,
+                          "isConstant": false,
+                          "isLValue": false,
+                          "isPure": false,
+                          "lValueRequested": false,
+                          "nodeType": "UnaryOperation",
+                          "operator": "delete",
+                          "prefix": true,
+                          "src": "36409:26:1",
+                          "subExpression": {
+                            "argumentTypes": null,
+                            "baseExpression": {
+                              "argumentTypes": null,
+                              "id": 1439,
+                              "name": "_tokenURIs",
+                              "nodeType": "Identifier",
+                              "overloadedDeclarations": [],
+                              "referencedDeclaration": 1338,
+                              "src": "36416:10:1",
+                              "typeDescriptions": {
+                                "typeIdentifier": "t_mapping$_t_uint256_$_t_string_storage_$",
+                                "typeString": "mapping(uint256 => string storage ref)"
+                              }
+                            },
+                            "id": 1441,
+                            "indexExpression": {
+                              "argumentTypes": null,
+                              "id": 1440,
+                              "name": "tokenId",
+                              "nodeType": "Identifier",
+                              "overloadedDeclarations": [],
+                              "referencedDeclaration": 1421,
+                              "src": "36427:7:1",
+                              "typeDescriptions": {
+                                "typeIdentifier": "t_uint256",
+                                "typeString": "uint256"
+                              }
+                            },
+                            "isConstant": false,
+                            "isLValue": true,
+                            "isPure": false,
+                            "lValueRequested": true,
+                            "nodeType": "IndexAccess",
+                            "src": "36416:19:1",
+                            "typeDescriptions": {
+                              "typeIdentifier": "t_string_storage",
+                              "typeString": "string storage ref"
+                            }
+                          },
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_tuple$__$",
+                            "typeString": "tuple()"
+                          }
+                        },
+                        "id": 1443,
+                        "nodeType": "ExpressionStatement",
+                        "src": "36409:26:1"
+                      }
+                    ]
+                  }
+                }
+              ]
+            },
+            "documentation": "@dev Internal function to burn a specific token.\nReverts if the token does not exist.\nDeprecated, use _burn(uint256) instead.\n@param owner owner of the token to burn\n@param tokenId uint256 ID of the token being burned by the msg.sender",
+            "id": 1447,
+            "implemented": true,
+            "kind": "function",
+            "modifiers": [],
+            "name": "_burn",
+            "nodeType": "FunctionDefinition",
+            "parameters": {
+              "id": 1422,
+              "nodeType": "ParameterList",
+              "parameters": [
+                {
+                  "constant": false,
+                  "id": 1419,
+                  "name": "owner",
+                  "nodeType": "VariableDeclaration",
+                  "scope": 1447,
+                  "src": "36227:13:1",
+                  "stateVariable": false,
+                  "storageLocation": "default",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_address",
+                    "typeString": "address"
+                  },
+                  "typeName": {
+                    "id": 1418,
+                    "name": "address",
+                    "nodeType": "ElementaryTypeName",
+                    "src": "36227:7:1",
+                    "stateMutability": "nonpayable",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_address",
+                      "typeString": "address"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                },
+                {
+                  "constant": false,
+                  "id": 1421,
+                  "name": "tokenId",
+                  "nodeType": "VariableDeclaration",
+                  "scope": 1447,
+                  "src": "36242:15:1",
+                  "stateVariable": false,
+                  "storageLocation": "default",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_uint256",
+                    "typeString": "uint256"
+                  },
+                  "typeName": {
+                    "id": 1420,
+                    "name": "uint256",
+                    "nodeType": "ElementaryTypeName",
+                    "src": "36242:7:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_uint256",
+                      "typeString": "uint256"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                }
+              ],
+              "src": "36226:32:1"
+            },
+            "returnParameters": {
+              "id": 1423,
+              "nodeType": "ParameterList",
+              "parameters": [],
+              "src": "36268:0:1"
+            },
+            "scope": 1448,
+            "src": "36212:240:1",
+            "stateMutability": "nonpayable",
+            "superFunction": 811,
+            "visibility": "internal"
+          }
+        ],
+        "scope": 1469,
+        "src": "33817:2637:1"
+      },
+      {
+        "id": 1449,
+        "literals": [
+          "solidity",
+          "^",
+          "0.5",
+          ".0"
+        ],
+        "nodeType": "PragmaDirective",
+        "src": "36518:23:1"
+      },
+      {
+        "baseContracts": [
+          {
+            "arguments": null,
+            "baseName": {
+              "contractScope": null,
+              "id": 1450,
+              "name": "ERC721",
+              "nodeType": "UserDefinedTypeName",
+              "referencedDeclaration": 944,
+              "src": "36838:6:1",
+              "typeDescriptions": {
+                "typeIdentifier": "t_contract$_ERC721_$944",
+                "typeString": "contract ERC721"
+              }
+            },
+            "id": 1451,
+            "nodeType": "InheritanceSpecifier",
+            "src": "36838:6:1"
+          },
+          {
+            "arguments": null,
+            "baseName": {
+              "contractScope": null,
+              "id": 1452,
+              "name": "ERC721Enumerable",
+              "nodeType": "UserDefinedTypeName",
+              "referencedDeclaration": 1302,
+              "src": "36846:16:1",
+              "typeDescriptions": {
+                "typeIdentifier": "t_contract$_ERC721Enumerable_$1302",
+                "typeString": "contract ERC721Enumerable"
+              }
+            },
+            "id": 1453,
+            "nodeType": "InheritanceSpecifier",
+            "src": "36846:16:1"
+          },
+          {
+            "arguments": null,
+            "baseName": {
+              "contractScope": null,
+              "id": 1454,
+              "name": "ERC721Metadata",
+              "nodeType": "UserDefinedTypeName",
+              "referencedDeclaration": 1448,
+              "src": "36864:14:1",
+              "typeDescriptions": {
+                "typeIdentifier": "t_contract$_ERC721Metadata_$1448",
+                "typeString": "contract ERC721Metadata"
+              }
+            },
+            "id": 1455,
+            "nodeType": "InheritanceSpecifier",
+            "src": "36864:14:1"
+          }
+        ],
+        "contractDependencies": [
+          944,
+          969,
+          23,
+          124,
+          386,
+          1302,
+          1323,
+          1448
+        ],
+        "contractKind": "contract",
+        "documentation": "@title Full ERC721 Token\nThis implementation includes all the required and some optional functionality of the ERC721 standard\nMoreover, it includes approve all functionality using operator terminology\n@dev see https://eips.ethereum.org/EIPS/eip-721",
+        "fullyImplemented": true,
+        "id": 1468,
+        "linearizedBaseContracts": [
+          1468,
+          1448,
+          1323,
+          1302,
+          969,
+          944,
+          124,
+          386,
+          23
+        ],
+        "name": "ERC721Full",
+        "nodeType": "ContractDefinition",
+        "nodes": [
+          {
+            "body": {
+              "id": 1466,
+              "nodeType": "Block",
+              "src": "36976:64:1",
+              "statements": []
+            },
+            "documentation": null,
+            "id": 1467,
+            "implemented": true,
+            "kind": "constructor",
+            "modifiers": [
+              {
+                "arguments": [
+                  {
+                    "argumentTypes": null,
+                    "id": 1462,
+                    "name": "name",
+                    "nodeType": "Identifier",
+                    "overloadedDeclarations": [],
+                    "referencedDeclaration": 1457,
+                    "src": "36962:4:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_string_memory_ptr",
+                      "typeString": "string memory"
+                    }
+                  },
+                  {
+                    "argumentTypes": null,
+                    "id": 1463,
+                    "name": "symbol",
+                    "nodeType": "Identifier",
+                    "overloadedDeclarations": [],
+                    "referencedDeclaration": 1459,
+                    "src": "36968:6:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_string_memory_ptr",
+                      "typeString": "string memory"
+                    }
+                  }
+                ],
+                "id": 1464,
+                "modifierName": {
+                  "argumentTypes": null,
+                  "id": 1461,
+                  "name": "ERC721Metadata",
+                  "nodeType": "Identifier",
+                  "overloadedDeclarations": [],
+                  "referencedDeclaration": 1448,
+                  "src": "36947:14:1",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_type$_t_contract$_ERC721Metadata_$1448_$",
+                    "typeString": "type(contract ERC721Metadata)"
+                  }
+                },
+                "nodeType": "ModifierInvocation",
+                "src": "36947:28:1"
+              }
+            ],
+            "name": "",
+            "nodeType": "FunctionDefinition",
+            "parameters": {
+              "id": 1460,
+              "nodeType": "ParameterList",
+              "parameters": [
+                {
+                  "constant": false,
+                  "id": 1457,
+                  "name": "name",
+                  "nodeType": "VariableDeclaration",
+                  "scope": 1467,
+                  "src": "36898:18:1",
+                  "stateVariable": false,
+                  "storageLocation": "memory",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_string_memory_ptr",
+                    "typeString": "string"
+                  },
+                  "typeName": {
+                    "id": 1456,
+                    "name": "string",
+                    "nodeType": "ElementaryTypeName",
+                    "src": "36898:6:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_string_storage_ptr",
+                      "typeString": "string"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                },
+                {
+                  "constant": false,
+                  "id": 1459,
+                  "name": "symbol",
+                  "nodeType": "VariableDeclaration",
+                  "scope": 1467,
+                  "src": "36918:20:1",
+                  "stateVariable": false,
+                  "storageLocation": "memory",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_string_memory_ptr",
+                    "typeString": "string"
+                  },
+                  "typeName": {
+                    "id": 1458,
+                    "name": "string",
+                    "nodeType": "ElementaryTypeName",
+                    "src": "36918:6:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_string_storage_ptr",
+                      "typeString": "string"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                }
+              ],
+              "src": "36897:42:1"
+            },
+            "returnParameters": {
+              "id": 1465,
+              "nodeType": "ParameterList",
+              "parameters": [],
+              "src": "36976:0:1"
+            },
+            "scope": 1468,
+            "src": "36885:155:1",
+            "stateMutability": "nonpayable",
+            "superFunction": null,
+            "visibility": "public"
+          }
+        ],
+        "scope": 1469,
+        "src": "36815:227:1"
+      }
+    ],
+    "src": "61:36982:1"
+  },
+  "compiler": {
+    "name": "solc",
+    "version": "0.5.0+commit.1d4f565a.Emscripten.clang"
+  },
+  "networks": {},
+  "schemaVersion": "3.0.2",
+  "updatedAt": "2019-09-05T15:01:08.572Z",
+  "devdoc": {
+    "details": "Implementation of the `IERC165` interface. * Contracts may inherit from this and call `_registerInterface` to declare their support of an interface.",
+    "methods": {
+      "supportsInterface(bytes4)": {
+        "details": "See `IERC165.supportsInterface`.     * Time complexity O(1), guaranteed to always use less than 30 000 gas."
+      }
+    }
+  },
+  "userdoc": {
+    "methods": {}
+  }
+}
\ No newline at end of file
diff --git a/src/abis/ERC721.json b/src/abis/ERC721.json
new file mode 100644
index 0000000..049fb2f
--- /dev/null
+++ b/src/abis/ERC721.json
@@ -0,0 +1,37799 @@
+{
+  "contractName": "ERC721",
+  "abi": [
+    {
+      "constant": true,
+      "inputs": [
+        {
+          "name": "interfaceId",
+          "type": "bytes4"
+        }
+      ],
+      "name": "supportsInterface",
+      "outputs": [
+        {
+          "name": "",
+          "type": "bool"
+        }
+      ],
+      "payable": false,
+      "stateMutability": "view",
+      "type": "function"
+    },
+    {
+      "inputs": [],
+      "payable": false,
+      "stateMutability": "nonpayable",
+      "type": "constructor"
+    },
+    {
+      "anonymous": false,
+      "inputs": [
+        {
+          "indexed": true,
+          "name": "from",
+          "type": "address"
+        },
+        {
+          "indexed": true,
+          "name": "to",
+          "type": "address"
+        },
+        {
+          "indexed": true,
+          "name": "tokenId",
+          "type": "uint256"
+        }
+      ],
+      "name": "Transfer",
+      "type": "event"
+    },
+    {
+      "anonymous": false,
+      "inputs": [
+        {
+          "indexed": true,
+          "name": "owner",
+          "type": "address"
+        },
+        {
+          "indexed": true,
+          "name": "approved",
+          "type": "address"
+        },
+        {
+          "indexed": true,
+          "name": "tokenId",
+          "type": "uint256"
+        }
+      ],
+      "name": "Approval",
+      "type": "event"
+    },
+    {
+      "anonymous": false,
+      "inputs": [
+        {
+          "indexed": true,
+          "name": "owner",
+          "type": "address"
+        },
+        {
+          "indexed": true,
+          "name": "operator",
+          "type": "address"
+        },
+        {
+          "indexed": false,
+          "name": "approved",
+          "type": "bool"
+        }
+      ],
+      "name": "ApprovalForAll",
+      "type": "event"
+    },
+    {
+      "constant": true,
+      "inputs": [
+        {
+          "name": "owner",
+          "type": "address"
+        }
+      ],
+      "name": "balanceOf",
+      "outputs": [
+        {
+          "name": "",
+          "type": "uint256"
+        }
+      ],
+      "payable": false,
+      "stateMutability": "view",
+      "type": "function"
+    },
+    {
+      "constant": true,
+      "inputs": [
+        {
+          "name": "tokenId",
+          "type": "uint256"
+        }
+      ],
+      "name": "ownerOf",
+      "outputs": [
+        {
+          "name": "",
+          "type": "address"
+        }
+      ],
+      "payable": false,
+      "stateMutability": "view",
+      "type": "function"
+    },
+    {
+      "constant": false,
+      "inputs": [
+        {
+          "name": "to",
+          "type": "address"
+        },
+        {
+          "name": "tokenId",
+          "type": "uint256"
+        }
+      ],
+      "name": "approve",
+      "outputs": [],
+      "payable": false,
+      "stateMutability": "nonpayable",
+      "type": "function"
+    },
+    {
+      "constant": true,
+      "inputs": [
+        {
+          "name": "tokenId",
+          "type": "uint256"
+        }
+      ],
+      "name": "getApproved",
+      "outputs": [
+        {
+          "name": "",
+          "type": "address"
+        }
+      ],
+      "payable": false,
+      "stateMutability": "view",
+      "type": "function"
+    },
+    {
+      "constant": false,
+      "inputs": [
+        {
+          "name": "to",
+          "type": "address"
+        },
+        {
+          "name": "approved",
+          "type": "bool"
+        }
+      ],
+      "name": "setApprovalForAll",
+      "outputs": [],
+      "payable": false,
+      "stateMutability": "nonpayable",
+      "type": "function"
+    },
+    {
+      "constant": true,
+      "inputs": [
+        {
+          "name": "owner",
+          "type": "address"
+        },
+        {
+          "name": "operator",
+          "type": "address"
+        }
+      ],
+      "name": "isApprovedForAll",
+      "outputs": [
+        {
+          "name": "",
+          "type": "bool"
+        }
+      ],
+      "payable": false,
+      "stateMutability": "view",
+      "type": "function"
+    },
+    {
+      "constant": false,
+      "inputs": [
+        {
+          "name": "from",
+          "type": "address"
+        },
+        {
+          "name": "to",
+          "type": "address"
+        },
+        {
+          "name": "tokenId",
+          "type": "uint256"
+        }
+      ],
+      "name": "transferFrom",
+      "outputs": [],
+      "payable": false,
+      "stateMutability": "nonpayable",
+      "type": "function"
+    },
+    {
+      "constant": false,
+      "inputs": [
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+          "name": "from",
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+        {
+          "name": "to",
+          "type": "address"
+        },
+        {
+          "name": "tokenId",
+          "type": "uint256"
+        }
+      ],
+      "name": "safeTransferFrom",
+      "outputs": [],
+      "payable": false,
+      "stateMutability": "nonpayable",
+      "type": "function"
+    },
+    {
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+      "inputs": [
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+        },
+        {
+          "name": "_data",
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+      "name": "safeTransferFrom",
+      "outputs": [],
+      "payable": false,
+      "stateMutability": "nonpayable",
+      "type": "function"
+    }
+  ],
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+  "source": "\n// File: @openzeppelin/contracts/introspection/IERC165.sol\n\npragma solidity ^0.5.0;\n\n/**\n * @dev Interface of the ERC165 standard, as defined in the\n * [EIP](https://eips.ethereum.org/EIPS/eip-165).\n *\n * Implementers can declare support of contract interfaces, which can then be\n * queried by others (`ERC165Checker`).\n *\n * For an implementation, see `ERC165`.\n */\ninterface IERC165 {\n    /**\n     * @dev Returns true if this contract implements the interface defined by\n     * `interfaceId`. See the corresponding\n     * [EIP section](https://eips.ethereum.org/EIPS/eip-165#how-interfaces-are-identified)\n     * to learn more about how these ids are created.\n     *\n     * This function call must use less than 30 000 gas.\n     */\n    function supportsInterface(bytes4 interfaceId) external view returns (bool);\n}\n\n// File: @openzeppelin/contracts/token/ERC721/IERC721.sol\n\npragma solidity ^0.5.0;\n\n\n/**\n * @dev Required interface of an ERC721 compliant contract.\n */\ncontract IERC721 is IERC165 {\n    event Transfer(address indexed from, address indexed to, uint256 indexed tokenId);\n    event Approval(address indexed owner, address indexed approved, uint256 indexed tokenId);\n    event ApprovalForAll(address indexed owner, address indexed operator, bool approved);\n\n    /**\n     * @dev Returns the number of NFTs in `owner`'s account.\n     */\n    function balanceOf(address owner) public view returns (uint256 balance);\n\n    /**\n     * @dev Returns the owner of the NFT specified by `tokenId`.\n     */\n    function ownerOf(uint256 tokenId) public view returns (address owner);\n\n    /**\n     * @dev Transfers a specific NFT (`tokenId`) from one account (`from`) to\n     * another (`to`).\n     *\n     * \n     *\n     * Requirements:\n     * - `from`, `to` cannot be zero.\n     * - `tokenId` must be owned by `from`.\n     * - If the caller is not `from`, it must be have been allowed to move this\n     * NFT by either `approve` or `setApproveForAll`.\n     */\n    function safeTransferFrom(address from, address to, uint256 tokenId) public;\n    /**\n     * @dev Transfers a specific NFT (`tokenId`) from one account (`from`) to\n     * another (`to`).\n     *\n     * Requirements:\n     * - If the caller is not `from`, it must be approved to move this NFT by\n     * either `approve` or `setApproveForAll`.\n     */\n    function transferFrom(address from, address to, uint256 tokenId) public;\n    function approve(address to, uint256 tokenId) public;\n    function getApproved(uint256 tokenId) public view returns (address operator);\n\n    function setApprovalForAll(address operator, bool _approved) public;\n    function isApprovedForAll(address owner, address operator) public view returns (bool);\n\n\n    function safeTransferFrom(address from, address to, uint256 tokenId, bytes memory data) public;\n}\n\n// File: @openzeppelin/contracts/token/ERC721/IERC721Receiver.sol\n\npragma solidity ^0.5.0;\n\n/**\n * @title ERC721 token receiver interface\n * @dev Interface for any contract that wants to support safeTransfers\n * from ERC721 asset contracts.\n */\ncontract IERC721Receiver {\n    /**\n     * @notice Handle the receipt of an NFT\n     * @dev The ERC721 smart contract calls this function on the recipient\n     * after a `safeTransfer`. This function MUST return the function selector,\n     * otherwise the caller will revert the transaction. The selector to be\n     * returned can be obtained as `this.onERC721Received.selector`. This\n     * function MAY throw to revert and reject the transfer.\n     * Note: the ERC721 contract address is always the message sender.\n     * @param operator The address which called `safeTransferFrom` function\n     * @param from The address which previously owned the token\n     * @param tokenId The NFT identifier which is being transferred\n     * @param data Additional data with no specified format\n     * @return bytes4 `bytes4(keccak256(\"onERC721Received(address,address,uint256,bytes)\"))`\n     */\n    function onERC721Received(address operator, address from, uint256 tokenId, bytes memory data)\n    public returns (bytes4);\n}\n\n// File: @openzeppelin/contracts/math/SafeMath.sol\n\npragma solidity ^0.5.0;\n\n/**\n * @dev Wrappers over Solidity's arithmetic operations with added overflow\n * checks.\n *\n * Arithmetic operations in Solidity wrap on overflow. This can easily result\n * in bugs, because programmers usually assume that an overflow raises an\n * error, which is the standard behavior in high level programming languages.\n * `SafeMath` restores this intuition by reverting the transaction when an\n * operation overflows.\n *\n * Using this library instead of the unchecked operations eliminates an entire\n * class of bugs, so it's recommended to use it always.\n */\nlibrary SafeMath {\n    /**\n     * @dev Returns the addition of two unsigned integers, reverting on\n     * overflow.\n     *\n     * Counterpart to Solidity's `+` operator.\n     *\n     * Requirements:\n     * - Addition cannot overflow.\n     */\n    function add(uint256 a, uint256 b) internal pure returns (uint256) {\n        uint256 c = a + b;\n        require(c >= a, \"SafeMath: addition overflow\");\n\n        return c;\n    }\n\n    /**\n     * @dev Returns the subtraction of two unsigned integers, reverting on\n     * overflow (when the result is negative).\n     *\n     * Counterpart to Solidity's `-` operator.\n     *\n     * Requirements:\n     * - Subtraction cannot overflow.\n     */\n    function sub(uint256 a, uint256 b) internal pure returns (uint256) {\n        require(b <= a, \"SafeMath: subtraction overflow\");\n        uint256 c = a - b;\n\n        return c;\n    }\n\n    /**\n     * @dev Returns the multiplication of two unsigned integers, reverting on\n     * overflow.\n     *\n     * Counterpart to Solidity's `*` operator.\n     *\n     * Requirements:\n     * - Multiplication cannot overflow.\n     */\n    function mul(uint256 a, uint256 b) internal pure returns (uint256) {\n        // Gas optimization: this is cheaper than requiring 'a' not being zero, but the\n        // benefit is lost if 'b' is also tested.\n        // See: https://github.com/OpenZeppelin/openzeppelin-contracts/pull/522\n        if (a == 0) {\n            return 0;\n        }\n\n        uint256 c = a * b;\n        require(c / a == b, \"SafeMath: multiplication overflow\");\n\n        return c;\n    }\n\n    /**\n     * @dev Returns the integer division of two unsigned integers. Reverts on\n     * division by zero. The result is rounded towards zero.\n     *\n     * Counterpart to Solidity's `/` operator. Note: this function uses a\n     * `revert` opcode (which leaves remaining gas untouched) while Solidity\n     * uses an invalid opcode to revert (consuming all remaining gas).\n     *\n     * Requirements:\n     * - The divisor cannot be zero.\n     */\n    function div(uint256 a, uint256 b) internal pure returns (uint256) {\n        // Solidity only automatically asserts when dividing by 0\n        require(b > 0, \"SafeMath: division by zero\");\n        uint256 c = a / b;\n        // assert(a == b * c + a % b); // There is no case in which this doesn't hold\n\n        return c;\n    }\n\n    /**\n     * @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo),\n     * Reverts when dividing by zero.\n     *\n     * Counterpart to Solidity's `%` operator. This function uses a `revert`\n     * opcode (which leaves remaining gas untouched) while Solidity uses an\n     * invalid opcode to revert (consuming all remaining gas).\n     *\n     * Requirements:\n     * - The divisor cannot be zero.\n     */\n    function mod(uint256 a, uint256 b) internal pure returns (uint256) {\n        require(b != 0, \"SafeMath: modulo by zero\");\n        return a % b;\n    }\n}\n\n// File: @openzeppelin/contracts/utils/Address.sol\n\npragma solidity ^0.5.0;\n\n/**\n * @dev Collection of functions related to the address type,\n */\nlibrary Address {\n    /**\n     * @dev Returns true if `account` is a contract.\n     *\n     * This test is non-exhaustive, and there may be false-negatives: during the\n     * execution of a contract's constructor, its address will be reported as\n     * not containing a contract.\n     *\n     * > It is unsafe to assume that an address for which this function returns\n     * false is an externally-owned account (EOA) and not a contract.\n     */\n    function isContract(address account) internal view returns (bool) {\n        // This method relies in extcodesize, which returns 0 for contracts in\n        // construction, since the code is only stored at the end of the\n        // constructor execution.\n\n        uint256 size;\n        // solhint-disable-next-line no-inline-assembly\n        assembly { size := extcodesize(account) }\n        return size > 0;\n    }\n}\n\n// File: @openzeppelin/contracts/drafts/Counters.sol\n\npragma solidity ^0.5.0;\n\n\n/**\n * @title Counters\n * @author Matt Condon (@shrugs)\n * @dev Provides counters that can only be incremented or decremented by one. This can be used e.g. to track the number\n * of elements in a mapping, issuing ERC721 ids, or counting request ids.\n *\n * Include with `using Counters for Counters.Counter;`\n * Since it is not possible to overflow a 256 bit integer with increments of one, `increment` can skip the SafeMath\n * overflow check, thereby saving gas. This does assume however correct usage, in that the underlying `_value` is never\n * directly accessed.\n */\nlibrary Counters {\n    using SafeMath for uint256;\n\n    struct Counter {\n        // This variable should never be directly accessed by users of the library: interactions must be restricted to\n        // the library's function. As of Solidity v0.5.2, this cannot be enforced, though there is a proposal to add\n        // this feature: see https://github.com/ethereum/solidity/issues/4637\n        uint256 _value; // default: 0\n    }\n\n    function current(Counter storage counter) internal view returns (uint256) {\n        return counter._value;\n    }\n\n    function increment(Counter storage counter) internal {\n        counter._value += 1;\n    }\n\n    function decrement(Counter storage counter) internal {\n        counter._value = counter._value.sub(1);\n    }\n}\n\n// File: @openzeppelin/contracts/introspection/ERC165.sol\n\npragma solidity ^0.5.0;\n\n\n/**\n * @dev Implementation of the `IERC165` interface.\n *\n * Contracts may inherit from this and call `_registerInterface` to declare\n * their support of an interface.\n */\ncontract ERC165 is IERC165 {\n    /*\n     * bytes4(keccak256('supportsInterface(bytes4)')) == 0x01ffc9a7\n     */\n    bytes4 private constant _INTERFACE_ID_ERC165 = 0x01ffc9a7;\n\n    /**\n     * @dev Mapping of interface ids to whether or not it's supported.\n     */\n    mapping(bytes4 => bool) private _supportedInterfaces;\n\n    constructor () internal {\n        // Derived contracts need only register support for their own interfaces,\n        // we register support for ERC165 itself here\n        _registerInterface(_INTERFACE_ID_ERC165);\n    }\n\n    /**\n     * @dev See `IERC165.supportsInterface`.\n     *\n     * Time complexity O(1), guaranteed to always use less than 30 000 gas.\n     */\n    function supportsInterface(bytes4 interfaceId) external view returns (bool) {\n        return _supportedInterfaces[interfaceId];\n    }\n\n    /**\n     * @dev Registers the contract as an implementer of the interface defined by\n     * `interfaceId`. Support of the actual ERC165 interface is automatic and\n     * registering its interface id is not required.\n     *\n     * See `IERC165.supportsInterface`.\n     *\n     * Requirements:\n     *\n     * - `interfaceId` cannot be the ERC165 invalid interface (`0xffffffff`).\n     */\n    function _registerInterface(bytes4 interfaceId) internal {\n        require(interfaceId != 0xffffffff, \"ERC165: invalid interface id\");\n        _supportedInterfaces[interfaceId] = true;\n    }\n}\n\n// File: @openzeppelin/contracts/token/ERC721/ERC721.sol\n\npragma solidity ^0.5.0;\n\n\n\n\n\n\n\n/**\n * @title ERC721 Non-Fungible Token Standard basic implementation\n * @dev see https://eips.ethereum.org/EIPS/eip-721\n */\ncontract ERC721 is ERC165, IERC721 {\n    using SafeMath for uint256;\n    using Address for address;\n    using Counters for Counters.Counter;\n\n    // Equals to `bytes4(keccak256(\"onERC721Received(address,address,uint256,bytes)\"))`\n    // which can be also obtained as `IERC721Receiver(0).onERC721Received.selector`\n    bytes4 private constant _ERC721_RECEIVED = 0x150b7a02;\n\n    // Mapping from token ID to owner\n    mapping (uint256 => address) private _tokenOwner;\n\n    // Mapping from token ID to approved address\n    mapping (uint256 => address) private _tokenApprovals;\n\n    // Mapping from owner to number of owned token\n    mapping (address => Counters.Counter) private _ownedTokensCount;\n\n    // Mapping from owner to operator approvals\n    mapping (address => mapping (address => bool)) private _operatorApprovals;\n\n    /*\n     *     bytes4(keccak256('balanceOf(address)')) == 0x70a08231\n     *     bytes4(keccak256('ownerOf(uint256)')) == 0x6352211e\n     *     bytes4(keccak256('approve(address,uint256)')) == 0x095ea7b3\n     *     bytes4(keccak256('getApproved(uint256)')) == 0x081812fc\n     *     bytes4(keccak256('setApprovalForAll(address,bool)')) == 0xa22cb465\n     *     bytes4(keccak256('isApprovedForAll(address,address)')) == 0xe985e9c\n     *     bytes4(keccak256('transferFrom(address,address,uint256)')) == 0x23b872dd\n     *     bytes4(keccak256('safeTransferFrom(address,address,uint256)')) == 0x42842e0e\n     *     bytes4(keccak256('safeTransferFrom(address,address,uint256,bytes)')) == 0xb88d4fde\n     *\n     *     => 0x70a08231 ^ 0x6352211e ^ 0x095ea7b3 ^ 0x081812fc ^\n     *        0xa22cb465 ^ 0xe985e9c ^ 0x23b872dd ^ 0x42842e0e ^ 0xb88d4fde == 0x80ac58cd\n     */\n    bytes4 private constant _INTERFACE_ID_ERC721 = 0x80ac58cd;\n\n    constructor () public {\n        // register the supported interfaces to conform to ERC721 via ERC165\n        _registerInterface(_INTERFACE_ID_ERC721);\n    }\n\n    /**\n     * @dev Gets the balance of the specified address.\n     * @param owner address to query the balance of\n     * @return uint256 representing the amount owned by the passed address\n     */\n    function balanceOf(address owner) public view returns (uint256) {\n        require(owner != address(0), \"ERC721: balance query for the zero address\");\n\n        return _ownedTokensCount[owner].current();\n    }\n\n    /**\n     * @dev Gets the owner of the specified token ID.\n     * @param tokenId uint256 ID of the token to query the owner of\n     * @return address currently marked as the owner of the given token ID\n     */\n    function ownerOf(uint256 tokenId) public view returns (address) {\n        address owner = _tokenOwner[tokenId];\n        require(owner != address(0), \"ERC721: owner query for nonexistent token\");\n\n        return owner;\n    }\n\n    /**\n     * @dev Approves another address to transfer the given token ID\n     * The zero address indicates there is no approved address.\n     * There can only be one approved address per token at a given time.\n     * Can only be called by the token owner or an approved operator.\n     * @param to address to be approved for the given token ID\n     * @param tokenId uint256 ID of the token to be approved\n     */\n    function approve(address to, uint256 tokenId) public {\n        address owner = ownerOf(tokenId);\n        require(to != owner, \"ERC721: approval to current owner\");\n\n        require(msg.sender == owner || isApprovedForAll(owner, msg.sender),\n            \"ERC721: approve caller is not owner nor approved for all\"\n        );\n\n        _tokenApprovals[tokenId] = to;\n        emit Approval(owner, to, tokenId);\n    }\n\n    /**\n     * @dev Gets the approved address for a token ID, or zero if no address set\n     * Reverts if the token ID does not exist.\n     * @param tokenId uint256 ID of the token to query the approval of\n     * @return address currently approved for the given token ID\n     */\n    function getApproved(uint256 tokenId) public view returns (address) {\n        require(_exists(tokenId), \"ERC721: approved query for nonexistent token\");\n\n        return _tokenApprovals[tokenId];\n    }\n\n    /**\n     * @dev Sets or unsets the approval of a given operator\n     * An operator is allowed to transfer all tokens of the sender on their behalf.\n     * @param to operator address to set the approval\n     * @param approved representing the status of the approval to be set\n     */\n    function setApprovalForAll(address to, bool approved) public {\n        require(to != msg.sender, \"ERC721: approve to caller\");\n\n        _operatorApprovals[msg.sender][to] = approved;\n        emit ApprovalForAll(msg.sender, to, approved);\n    }\n\n    /**\n     * @dev Tells whether an operator is approved by a given owner.\n     * @param owner owner address which you want to query the approval of\n     * @param operator operator address which you want to query the approval of\n     * @return bool whether the given operator is approved by the given owner\n     */\n    function isApprovedForAll(address owner, address operator) public view returns (bool) {\n        return _operatorApprovals[owner][operator];\n    }\n\n    /**\n     * @dev Transfers the ownership of a given token ID to another address.\n     * Usage of this method is discouraged, use `safeTransferFrom` whenever possible.\n     * Requires the msg.sender to be the owner, approved, or operator.\n     * @param from current owner of the token\n     * @param to address to receive the ownership of the given token ID\n     * @param tokenId uint256 ID of the token to be transferred\n     */\n    function transferFrom(address from, address to, uint256 tokenId) public {\n        //solhint-disable-next-line max-line-length\n        require(_isApprovedOrOwner(msg.sender, tokenId), \"ERC721: transfer caller is not owner nor approved\");\n\n        _transferFrom(from, to, tokenId);\n    }\n\n    /**\n     * @dev Safely transfers the ownership of a given token ID to another address\n     * If the target address is a contract, it must implement `onERC721Received`,\n     * which is called upon a safe transfer, and return the magic value\n     * `bytes4(keccak256(\"onERC721Received(address,address,uint256,bytes)\"))`; otherwise,\n     * the transfer is reverted.\n     * Requires the msg.sender to be the owner, approved, or operator\n     * @param from current owner of the token\n     * @param to address to receive the ownership of the given token ID\n     * @param tokenId uint256 ID of the token to be transferred\n     */\n    function safeTransferFrom(address from, address to, uint256 tokenId) public {\n        safeTransferFrom(from, to, tokenId, \"\");\n    }\n\n    /**\n     * @dev Safely transfers the ownership of a given token ID to another address\n     * If the target address is a contract, it must implement `onERC721Received`,\n     * which is called upon a safe transfer, and return the magic value\n     * `bytes4(keccak256(\"onERC721Received(address,address,uint256,bytes)\"))`; otherwise,\n     * the transfer is reverted.\n     * Requires the msg.sender to be the owner, approved, or operator\n     * @param from current owner of the token\n     * @param to address to receive the ownership of the given token ID\n     * @param tokenId uint256 ID of the token to be transferred\n     * @param _data bytes data to send along with a safe transfer check\n     */\n    function safeTransferFrom(address from, address to, uint256 tokenId, bytes memory _data) public {\n        transferFrom(from, to, tokenId);\n        require(_checkOnERC721Received(from, to, tokenId, _data), \"ERC721: transfer to non ERC721Receiver implementer\");\n    }\n\n    /**\n     * @dev Returns whether the specified token exists.\n     * @param tokenId uint256 ID of the token to query the existence of\n     * @return bool whether the token exists\n     */\n    function _exists(uint256 tokenId) internal view returns (bool) {\n        address owner = _tokenOwner[tokenId];\n        return owner != address(0);\n    }\n\n    /**\n     * @dev Returns whether the given spender can transfer a given token ID.\n     * @param spender address of the spender to query\n     * @param tokenId uint256 ID of the token to be transferred\n     * @return bool whether the msg.sender is approved for the given token ID,\n     * is an operator of the owner, or is the owner of the token\n     */\n    function _isApprovedOrOwner(address spender, uint256 tokenId) internal view returns (bool) {\n        require(_exists(tokenId), \"ERC721: operator query for nonexistent token\");\n        address owner = ownerOf(tokenId);\n        return (spender == owner || getApproved(tokenId) == spender || isApprovedForAll(owner, spender));\n    }\n\n    /**\n     * @dev Internal function to mint a new token.\n     * Reverts if the given token ID already exists.\n     * @param to The address that will own the minted token\n     * @param tokenId uint256 ID of the token to be minted\n     */\n    function _mint(address to, uint256 tokenId) internal {\n        require(to != address(0), \"ERC721: mint to the zero address\");\n        require(!_exists(tokenId), \"ERC721: token already minted\");\n\n        _tokenOwner[tokenId] = to;\n        _ownedTokensCount[to].increment();\n\n        emit Transfer(address(0), to, tokenId);\n    }\n\n    /**\n     * @dev Internal function to burn a specific token.\n     * Reverts if the token does not exist.\n     * Deprecated, use _burn(uint256) instead.\n     * @param owner owner of the token to burn\n     * @param tokenId uint256 ID of the token being burned\n     */\n    function _burn(address owner, uint256 tokenId) internal {\n        require(ownerOf(tokenId) == owner, \"ERC721: burn of token that is not own\");\n\n        _clearApproval(tokenId);\n\n        _ownedTokensCount[owner].decrement();\n        _tokenOwner[tokenId] = address(0);\n\n        emit Transfer(owner, address(0), tokenId);\n    }\n\n    /**\n     * @dev Internal function to burn a specific token.\n     * Reverts if the token does not exist.\n     * @param tokenId uint256 ID of the token being burned\n     */\n    function _burn(uint256 tokenId) internal {\n        _burn(ownerOf(tokenId), tokenId);\n    }\n\n    /**\n     * @dev Internal function to transfer ownership of a given token ID to another address.\n     * As opposed to transferFrom, this imposes no restrictions on msg.sender.\n     * @param from current owner of the token\n     * @param to address to receive the ownership of the given token ID\n     * @param tokenId uint256 ID of the token to be transferred\n     */\n    function _transferFrom(address from, address to, uint256 tokenId) internal {\n        require(ownerOf(tokenId) == from, \"ERC721: transfer of token that is not own\");\n        require(to != address(0), \"ERC721: transfer to the zero address\");\n\n        _clearApproval(tokenId);\n\n        _ownedTokensCount[from].decrement();\n        _ownedTokensCount[to].increment();\n\n        _tokenOwner[tokenId] = to;\n\n        emit Transfer(from, to, tokenId);\n    }\n\n    /**\n     * @dev Internal function to invoke `onERC721Received` on a target address.\n     * The call is not executed if the target address is not a contract.\n     *\n     * This function is deprecated.\n     * @param from address representing the previous owner of the given token ID\n     * @param to target address that will receive the tokens\n     * @param tokenId uint256 ID of the token to be transferred\n     * @param _data bytes optional data to send along with the call\n     * @return bool whether the call correctly returned the expected magic value\n     */\n    function _checkOnERC721Received(address from, address to, uint256 tokenId, bytes memory _data)\n        internal returns (bool)\n    {\n        if (!to.isContract()) {\n            return true;\n        }\n\n        bytes4 retval = IERC721Receiver(to).onERC721Received(msg.sender, from, tokenId, _data);\n        return (retval == _ERC721_RECEIVED);\n    }\n\n    /**\n     * @dev Private function to clear current approval of a given token ID.\n     * @param tokenId uint256 ID of the token to be transferred\n     */\n    function _clearApproval(uint256 tokenId) private {\n        if (_tokenApprovals[tokenId] != address(0)) {\n            _tokenApprovals[tokenId] = address(0);\n        }\n    }\n}\n\n// File: @openzeppelin/contracts/token/ERC721/IERC721Enumerable.sol\n\npragma solidity ^0.5.0;\n\n\n/**\n * @title ERC-721 Non-Fungible Token Standard, optional enumeration extension\n * @dev See https://eips.ethereum.org/EIPS/eip-721\n */\ncontract IERC721Enumerable is IERC721 {\n    function totalSupply() public view returns (uint256);\n    function tokenOfOwnerByIndex(address owner, uint256 index) public view returns (uint256 tokenId);\n\n    function tokenByIndex(uint256 index) public view returns (uint256);\n}\n\n// File: @openzeppelin/contracts/token/ERC721/ERC721Enumerable.sol\n\npragma solidity ^0.5.0;\n\n\n\n\n/**\n * @title ERC-721 Non-Fungible Token with optional enumeration extension logic\n * @dev See https://eips.ethereum.org/EIPS/eip-721\n */\ncontract ERC721Enumerable is ERC165, ERC721, IERC721Enumerable {\n    // Mapping from owner to list of owned token IDs\n    mapping(address => uint256[]) private _ownedTokens;\n\n    // Mapping from token ID to index of the owner tokens list\n    mapping(uint256 => uint256) private _ownedTokensIndex;\n\n    // Array with all token ids, used for enumeration\n    uint256[] private _allTokens;\n\n    // Mapping from token id to position in the allTokens array\n    mapping(uint256 => uint256) private _allTokensIndex;\n\n    /*\n     *     bytes4(keccak256('totalSupply()')) == 0x18160ddd\n     *     bytes4(keccak256('tokenOfOwnerByIndex(address,uint256)')) == 0x2f745c59\n     *     bytes4(keccak256('tokenByIndex(uint256)')) == 0x4f6ccce7\n     *\n     *     => 0x18160ddd ^ 0x2f745c59 ^ 0x4f6ccce7 == 0x780e9d63\n     */\n    bytes4 private constant _INTERFACE_ID_ERC721_ENUMERABLE = 0x780e9d63;\n\n    /**\n     * @dev Constructor function.\n     */\n    constructor () public {\n        // register the supported interface to conform to ERC721Enumerable via ERC165\n        _registerInterface(_INTERFACE_ID_ERC721_ENUMERABLE);\n    }\n\n    /**\n     * @dev Gets the token ID at a given index of the tokens list of the requested owner.\n     * @param owner address owning the tokens list to be accessed\n     * @param index uint256 representing the index to be accessed of the requested tokens list\n     * @return uint256 token ID at the given index of the tokens list owned by the requested address\n     */\n    function tokenOfOwnerByIndex(address owner, uint256 index) public view returns (uint256) {\n        require(index < balanceOf(owner), \"ERC721Enumerable: owner index out of bounds\");\n        return _ownedTokens[owner][index];\n    }\n\n    /**\n     * @dev Gets the total amount of tokens stored by the contract.\n     * @return uint256 representing the total amount of tokens\n     */\n    function totalSupply() public view returns (uint256) {\n        return _allTokens.length;\n    }\n\n    /**\n     * @dev Gets the token ID at a given index of all the tokens in this contract\n     * Reverts if the index is greater or equal to the total number of tokens.\n     * @param index uint256 representing the index to be accessed of the tokens list\n     * @return uint256 token ID at the given index of the tokens list\n     */\n    function tokenByIndex(uint256 index) public view returns (uint256) {\n        require(index < totalSupply(), \"ERC721Enumerable: global index out of bounds\");\n        return _allTokens[index];\n    }\n\n    /**\n     * @dev Internal function to transfer ownership of a given token ID to another address.\n     * As opposed to transferFrom, this imposes no restrictions on msg.sender.\n     * @param from current owner of the token\n     * @param to address to receive the ownership of the given token ID\n     * @param tokenId uint256 ID of the token to be transferred\n     */\n    function _transferFrom(address from, address to, uint256 tokenId) internal {\n        super._transferFrom(from, to, tokenId);\n\n        _removeTokenFromOwnerEnumeration(from, tokenId);\n\n        _addTokenToOwnerEnumeration(to, tokenId);\n    }\n\n    /**\n     * @dev Internal function to mint a new token.\n     * Reverts if the given token ID already exists.\n     * @param to address the beneficiary that will own the minted token\n     * @param tokenId uint256 ID of the token to be minted\n     */\n    function _mint(address to, uint256 tokenId) internal {\n        super._mint(to, tokenId);\n\n        _addTokenToOwnerEnumeration(to, tokenId);\n\n        _addTokenToAllTokensEnumeration(tokenId);\n    }\n\n    /**\n     * @dev Internal function to burn a specific token.\n     * Reverts if the token does not exist.\n     * Deprecated, use _burn(uint256) instead.\n     * @param owner owner of the token to burn\n     * @param tokenId uint256 ID of the token being burned\n     */\n    function _burn(address owner, uint256 tokenId) internal {\n        super._burn(owner, tokenId);\n\n        _removeTokenFromOwnerEnumeration(owner, tokenId);\n        // Since tokenId will be deleted, we can clear its slot in _ownedTokensIndex to trigger a gas refund\n        _ownedTokensIndex[tokenId] = 0;\n\n        _removeTokenFromAllTokensEnumeration(tokenId);\n    }\n\n    /**\n     * @dev Gets the list of token IDs of the requested owner.\n     * @param owner address owning the tokens\n     * @return uint256[] List of token IDs owned by the requested address\n     */\n    function _tokensOfOwner(address owner) internal view returns (uint256[] storage) {\n        return _ownedTokens[owner];\n    }\n\n    /**\n     * @dev Private function to add a token to this extension's ownership-tracking data structures.\n     * @param to address representing the new owner of the given token ID\n     * @param tokenId uint256 ID of the token to be added to the tokens list of the given address\n     */\n    function _addTokenToOwnerEnumeration(address to, uint256 tokenId) private {\n        _ownedTokensIndex[tokenId] = _ownedTokens[to].length;\n        _ownedTokens[to].push(tokenId);\n    }\n\n    /**\n     * @dev Private function to add a token to this extension's token tracking data structures.\n     * @param tokenId uint256 ID of the token to be added to the tokens list\n     */\n    function _addTokenToAllTokensEnumeration(uint256 tokenId) private {\n        _allTokensIndex[tokenId] = _allTokens.length;\n        _allTokens.push(tokenId);\n    }\n\n    /**\n     * @dev Private function to remove a token from this extension's ownership-tracking data structures. Note that\n     * while the token is not assigned a new owner, the _ownedTokensIndex mapping is _not_ updated: this allows for\n     * gas optimizations e.g. when performing a transfer operation (avoiding double writes).\n     * This has O(1) time complexity, but alters the order of the _ownedTokens array.\n     * @param from address representing the previous owner of the given token ID\n     * @param tokenId uint256 ID of the token to be removed from the tokens list of the given address\n     */\n    function _removeTokenFromOwnerEnumeration(address from, uint256 tokenId) private {\n        // To prevent a gap in from's tokens array, we store the last token in the index of the token to delete, and\n        // then delete the last slot (swap and pop).\n\n        uint256 lastTokenIndex = _ownedTokens[from].length.sub(1);\n        uint256 tokenIndex = _ownedTokensIndex[tokenId];\n\n        // When the token to delete is the last token, the swap operation is unnecessary\n        if (tokenIndex != lastTokenIndex) {\n            uint256 lastTokenId = _ownedTokens[from][lastTokenIndex];\n\n            _ownedTokens[from][tokenIndex] = lastTokenId; // Move the last token to the slot of the to-delete token\n            _ownedTokensIndex[lastTokenId] = tokenIndex; // Update the moved token's index\n        }\n\n        // This also deletes the contents at the last position of the array\n        _ownedTokens[from].length--;\n\n        // Note that _ownedTokensIndex[tokenId] hasn't been cleared: it still points to the old slot (now occupied by\n        // lastTokenId, or just over the end of the array if the token was the last one).\n    }\n\n    /**\n     * @dev Private function to remove a token from this extension's token tracking data structures.\n     * This has O(1) time complexity, but alters the order of the _allTokens array.\n     * @param tokenId uint256 ID of the token to be removed from the tokens list\n     */\n    function _removeTokenFromAllTokensEnumeration(uint256 tokenId) private {\n        // To prevent a gap in the tokens array, we store the last token in the index of the token to delete, and\n        // then delete the last slot (swap and pop).\n\n        uint256 lastTokenIndex = _allTokens.length.sub(1);\n        uint256 tokenIndex = _allTokensIndex[tokenId];\n\n        // When the token to delete is the last token, the swap operation is unnecessary. However, since this occurs so\n        // rarely (when the last minted token is burnt) that we still do the swap here to avoid the gas cost of adding\n        // an 'if' statement (like in _removeTokenFromOwnerEnumeration)\n        uint256 lastTokenId = _allTokens[lastTokenIndex];\n\n        _allTokens[tokenIndex] = lastTokenId; // Move the last token to the slot of the to-delete token\n        _allTokensIndex[lastTokenId] = tokenIndex; // Update the moved token's index\n\n        // This also deletes the contents at the last position of the array\n        _allTokens.length--;\n        _allTokensIndex[tokenId] = 0;\n    }\n}\n\n// File: @openzeppelin/contracts/token/ERC721/IERC721Metadata.sol\n\npragma solidity ^0.5.0;\n\n\n/**\n * @title ERC-721 Non-Fungible Token Standard, optional metadata extension\n * @dev See https://eips.ethereum.org/EIPS/eip-721\n */\ncontract IERC721Metadata is IERC721 {\n    function name() external view returns (string memory);\n    function symbol() external view returns (string memory);\n    function tokenURI(uint256 tokenId) external view returns (string memory);\n}\n\n// File: @openzeppelin/contracts/token/ERC721/ERC721Metadata.sol\n\npragma solidity ^0.5.0;\n\n\n\n\ncontract ERC721Metadata is ERC165, ERC721, IERC721Metadata {\n    // Token name\n    string private _name;\n\n    // Token symbol\n    string private _symbol;\n\n    // Optional mapping for token URIs\n    mapping(uint256 => string) private _tokenURIs;\n\n    /*\n     *     bytes4(keccak256('name()')) == 0x06fdde03\n     *     bytes4(keccak256('symbol()')) == 0x95d89b41\n     *     bytes4(keccak256('tokenURI(uint256)')) == 0xc87b56dd\n     *\n     *     => 0x06fdde03 ^ 0x95d89b41 ^ 0xc87b56dd == 0x5b5e139f\n     */\n    bytes4 private constant _INTERFACE_ID_ERC721_METADATA = 0x5b5e139f;\n\n    /**\n     * @dev Constructor function\n     */\n    constructor (string memory name, string memory symbol) public {\n        _name = name;\n        _symbol = symbol;\n\n        // register the supported interfaces to conform to ERC721 via ERC165\n        _registerInterface(_INTERFACE_ID_ERC721_METADATA);\n    }\n\n    /**\n     * @dev Gets the token name.\n     * @return string representing the token name\n     */\n    function name() external view returns (string memory) {\n        return _name;\n    }\n\n    /**\n     * @dev Gets the token symbol.\n     * @return string representing the token symbol\n     */\n    function symbol() external view returns (string memory) {\n        return _symbol;\n    }\n\n    /**\n     * @dev Returns an URI for a given token ID.\n     * Throws if the token ID does not exist. May return an empty string.\n     * @param tokenId uint256 ID of the token to query\n     */\n    function tokenURI(uint256 tokenId) external view returns (string memory) {\n        require(_exists(tokenId), \"ERC721Metadata: URI query for nonexistent token\");\n        return _tokenURIs[tokenId];\n    }\n\n    /**\n     * @dev Internal function to set the token URI for a given token.\n     * Reverts if the token ID does not exist.\n     * @param tokenId uint256 ID of the token to set its URI\n     * @param uri string URI to assign\n     */\n    function _setTokenURI(uint256 tokenId, string memory uri) internal {\n        require(_exists(tokenId), \"ERC721Metadata: URI set of nonexistent token\");\n        _tokenURIs[tokenId] = uri;\n    }\n\n    /**\n     * @dev Internal function to burn a specific token.\n     * Reverts if the token does not exist.\n     * Deprecated, use _burn(uint256) instead.\n     * @param owner owner of the token to burn\n     * @param tokenId uint256 ID of the token being burned by the msg.sender\n     */\n    function _burn(address owner, uint256 tokenId) internal {\n        super._burn(owner, tokenId);\n\n        // Clear metadata (if any)\n        if (bytes(_tokenURIs[tokenId]).length != 0) {\n            delete _tokenURIs[tokenId];\n        }\n    }\n}\n\n// File: @openzeppelin/contracts/token/ERC721/ERC721Full.sol\n\npragma solidity ^0.5.0;\n\n\n\n\n/**\n * @title Full ERC721 Token\n * This implementation includes all the required and some optional functionality of the ERC721 standard\n * Moreover, it includes approve all functionality using operator terminology\n * @dev see https://eips.ethereum.org/EIPS/eip-721\n */\ncontract ERC721Full is ERC721, ERC721Enumerable, ERC721Metadata {\n    constructor (string memory name, string memory symbol) public ERC721Metadata(name, symbol) {\n        // solhint-disable-previous-line no-empty-blocks\n    }\n}\n",
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+                        "name": "to",
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+                        "src": "28287:2:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        }
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+                        "id": 1101,
+                        "name": "tokenId",
+                        "nodeType": "Identifier",
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+                        "src": "28291:7:1",
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+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
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+                    ],
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+                        {
+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        },
+                        {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
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+                      "nodeType": "Identifier",
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+                        "nodeType": "Identifier",
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+                        "src": "28342:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
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+                      "argumentTypes": [
+                        {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
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+                      "nodeType": "Identifier",
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+                      "src": "28310:31:1",
+                      "typeDescriptions": {
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+                  "src": "28310:40:1"
+                }
+              ]
+            },
+            "documentation": "@dev Internal function to mint a new token.\nReverts if the given token ID already exists.\n@param to address the beneficiary that will own the minted token\n@param tokenId uint256 ID of the token to be minted",
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+                  "stateVariable": false,
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+                    "typeString": "address"
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+                    "name": "address",
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+                    "src": "28176:7:1",
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+                    "typeDescriptions": {
+                      "typeIdentifier": "t_address",
+                      "typeString": "address"
+                    }
+                  },
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+                  "visibility": "internal"
+                },
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+                  "src": "28188:15:1",
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+                  "storageLocation": "default",
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+                      "typeString": "uint256"
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+                  "visibility": "internal"
+                }
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+                        "name": "owner",
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+                        "src": "28710:5:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        }
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+                        "name": "tokenId",
+                        "nodeType": "Identifier",
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+                        "src": "28717:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
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+                        {
+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        },
+                        {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
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+                        "name": "super",
+                        "nodeType": "Identifier",
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+                        "referencedDeclaration": 1572,
+                        "src": "28698:5:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_super$_ERC721Enumerable_$1302",
+                          "typeString": "contract super ERC721Enumerable"
+                        }
+                      },
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+                      "isConstant": false,
+                      "isLValue": false,
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+                      "lValueRequested": false,
+                      "memberName": "_burn",
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+                      "src": "28698:11:1",
+                      "typeDescriptions": {
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+                    "kind": "functionCall",
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+                        "name": "owner",
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+                        "src": "28769:5:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        }
+                      },
+                      {
+                        "argumentTypes": null,
+                        "id": 1125,
+                        "name": "tokenId",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 1113,
+                        "src": "28776:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      }
+                    ],
+                    "expression": {
+                      "argumentTypes": [
+                        {
+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        },
+                        {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      ],
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+                      "name": "_removeTokenFromOwnerEnumeration",
+                      "nodeType": "Identifier",
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+                      "src": "28736:32:1",
+                      "typeDescriptions": {
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+                        "typeString": "function (address,uint256)"
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+                    "isLValue": false,
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+                    "kind": "functionCall",
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+                    "nodeType": "FunctionCall",
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+                      "typeString": "tuple()"
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+                        "id": 1128,
+                        "name": "_ownedTokensIndex",
+                        "nodeType": "Identifier",
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+                        "referencedDeclaration": 985,
+                        "src": "28903:17:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_mapping$_t_uint256_$_t_uint256_$",
+                          "typeString": "mapping(uint256 => uint256)"
+                        }
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+                      "indexExpression": {
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+                        "id": 1129,
+                        "name": "tokenId",
+                        "nodeType": "Identifier",
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+                        "referencedDeclaration": 1113,
+                        "src": "28921:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
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+                      "nodeType": "IndexAccess",
+                      "src": "28903:26:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_uint256",
+                        "typeString": "uint256"
+                      }
+                    },
+                    "nodeType": "Assignment",
+                    "operator": "=",
+                    "rightHandSide": {
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+                      "hexValue": "30",
+                      "id": 1131,
+                      "isConstant": false,
+                      "isLValue": false,
+                      "isPure": true,
+                      "kind": "number",
+                      "lValueRequested": false,
+                      "nodeType": "Literal",
+                      "src": "28932:1:1",
+                      "subdenomination": null,
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_rational_0_by_1",
+                        "typeString": "int_const 0"
+                      },
+                      "value": "0"
+                    },
+                    "src": "28903:30:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_uint256",
+                      "typeString": "uint256"
+                    }
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+                  "nodeType": "ExpressionStatement",
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+                        "id": 1135,
+                        "name": "tokenId",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 1113,
+                        "src": "28981:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      }
+                    ],
+                    "expression": {
+                      "argumentTypes": [
+                        {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      ],
+                      "id": 1134,
+                      "name": "_removeTokenFromAllTokensEnumeration",
+                      "nodeType": "Identifier",
+                      "overloadedDeclarations": [],
+                      "referencedDeclaration": 1301,
+                      "src": "28944:36:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_function_internal_nonpayable$_t_uint256_$returns$__$",
+                        "typeString": "function (uint256)"
+                      }
+                    },
+                    "id": 1136,
+                    "isConstant": false,
+                    "isLValue": false,
+                    "isPure": false,
+                    "kind": "functionCall",
+                    "lValueRequested": false,
+                    "names": [],
+                    "nodeType": "FunctionCall",
+                    "src": "28944:45:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_tuple$__$",
+                      "typeString": "tuple()"
+                    }
+                  },
+                  "id": 1137,
+                  "nodeType": "ExpressionStatement",
+                  "src": "28944:45:1"
+                }
+              ]
+            },
+            "documentation": "@dev Internal function to burn a specific token.\nReverts if the token does not exist.\nDeprecated, use _burn(uint256) instead.\n@param owner owner of the token to burn\n@param tokenId uint256 ID of the token being burned",
+            "id": 1139,
+            "implemented": true,
+            "kind": "function",
+            "modifiers": [],
+            "name": "_burn",
+            "nodeType": "FunctionDefinition",
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+              "id": 1114,
+              "nodeType": "ParameterList",
+              "parameters": [
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+                  "id": 1111,
+                  "name": "owner",
+                  "nodeType": "VariableDeclaration",
+                  "scope": 1139,
+                  "src": "28647:13:1",
+                  "stateVariable": false,
+                  "storageLocation": "default",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_address",
+                    "typeString": "address"
+                  },
+                  "typeName": {
+                    "id": 1110,
+                    "name": "address",
+                    "nodeType": "ElementaryTypeName",
+                    "src": "28647:7:1",
+                    "stateMutability": "nonpayable",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_address",
+                      "typeString": "address"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                },
+                {
+                  "constant": false,
+                  "id": 1113,
+                  "name": "tokenId",
+                  "nodeType": "VariableDeclaration",
+                  "scope": 1139,
+                  "src": "28662:15:1",
+                  "stateVariable": false,
+                  "storageLocation": "default",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_uint256",
+                    "typeString": "uint256"
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+                    "name": "uint256",
+                    "nodeType": "ElementaryTypeName",
+                    "src": "28662:7:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_uint256",
+                      "typeString": "uint256"
+                    }
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+                  "value": null,
+                  "visibility": "internal"
+                }
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+              "src": "28646:32:1"
+            },
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+              "nodeType": "ParameterList",
+              "parameters": [],
+              "src": "28688:0:1"
+            },
+            "scope": 1302,
+            "src": "28632:364:1",
+            "stateMutability": "nonpayable",
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+            "visibility": "internal"
+          },
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+            "body": {
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+              "nodeType": "Block",
+              "src": "29282:43:1",
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+                  "expression": {
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+                    "baseExpression": {
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+                      "id": 1147,
+                      "name": "_ownedTokens",
+                      "nodeType": "Identifier",
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+                      "referencedDeclaration": 981,
+                      "src": "29299:12:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_mapping$_t_address_$_t_array$_t_uint256_$dyn_storage_$",
+                        "typeString": "mapping(address => uint256[] storage ref)"
+                      }
+                    },
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+                      "id": 1148,
+                      "name": "owner",
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+                      "referencedDeclaration": 1141,
+                      "src": "29312:5:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_address",
+                        "typeString": "address"
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+                    "isLValue": true,
+                    "isPure": false,
+                    "lValueRequested": false,
+                    "nodeType": "IndexAccess",
+                    "src": "29299:19:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_array$_t_uint256_$dyn_storage",
+                      "typeString": "uint256[] storage ref"
+                    }
+                  },
+                  "functionReturnParameters": 1146,
+                  "id": 1150,
+                  "nodeType": "Return",
+                  "src": "29292:26:1"
+                }
+              ]
+            },
+            "documentation": "@dev Gets the list of token IDs of the requested owner.\n@param owner address owning the tokens\n@return uint256[] List of token IDs owned by the requested address",
+            "id": 1152,
+            "implemented": true,
+            "kind": "function",
+            "modifiers": [],
+            "name": "_tokensOfOwner",
+            "nodeType": "FunctionDefinition",
+            "parameters": {
+              "id": 1142,
+              "nodeType": "ParameterList",
+              "parameters": [
+                {
+                  "constant": false,
+                  "id": 1141,
+                  "name": "owner",
+                  "nodeType": "VariableDeclaration",
+                  "scope": 1152,
+                  "src": "29225:13:1",
+                  "stateVariable": false,
+                  "storageLocation": "default",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_address",
+                    "typeString": "address"
+                  },
+                  "typeName": {
+                    "id": 1140,
+                    "name": "address",
+                    "nodeType": "ElementaryTypeName",
+                    "src": "29225:7:1",
+                    "stateMutability": "nonpayable",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_address",
+                      "typeString": "address"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                }
+              ],
+              "src": "29224:15:1"
+            },
+            "returnParameters": {
+              "id": 1146,
+              "nodeType": "ParameterList",
+              "parameters": [
+                {
+                  "constant": false,
+                  "id": 1145,
+                  "name": "",
+                  "nodeType": "VariableDeclaration",
+                  "scope": 1152,
+                  "src": "29263:17:1",
+                  "stateVariable": false,
+                  "storageLocation": "storage",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_array$_t_uint256_$dyn_storage_ptr",
+                    "typeString": "uint256[]"
+                  },
+                  "typeName": {
+                    "baseType": {
+                      "id": 1143,
+                      "name": "uint256",
+                      "nodeType": "ElementaryTypeName",
+                      "src": "29263:7:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_uint256",
+                        "typeString": "uint256"
+                      }
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+                    "length": null,
+                    "nodeType": "ArrayTypeName",
+                    "src": "29263:9:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_array$_t_uint256_$dyn_storage_ptr",
+                      "typeString": "uint256[]"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                }
+              ],
+              "src": "29262:19:1"
+            },
+            "scope": 1302,
+            "src": "29201:124:1",
+            "stateMutability": "view",
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+            "visibility": "internal"
+          },
+          {
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+              "nodeType": "Block",
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+                    "id": 1166,
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+                        "id": 1159,
+                        "name": "_ownedTokensIndex",
+                        "nodeType": "Identifier",
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+                        "referencedDeclaration": 985,
+                        "src": "29703:17:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_mapping$_t_uint256_$_t_uint256_$",
+                          "typeString": "mapping(uint256 => uint256)"
+                        }
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+                        "id": 1160,
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+                    "nodeType": "Block",
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+                    "statements": [
+                      {
+                        "assignments": [
+                          1222
+                        ],
+                        "declarations": [
+                          {
+                            "constant": false,
+                            "id": 1222,
+                            "name": "lastTokenId",
+                            "nodeType": "VariableDeclaration",
+                            "scope": 1243,
+                            "src": "31297:19:1",
+                            "stateVariable": false,
+                            "storageLocation": "default",
+                            "typeDescriptions": {
+                              "typeIdentifier": "t_uint256",
+                              "typeString": "uint256"
+                            },
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+                              "name": "uint256",
+                              "nodeType": "ElementaryTypeName",
+                              "src": "31297:7:1",
+                              "typeDescriptions": {
+                                "typeIdentifier": "t_uint256",
+                                "typeString": "uint256"
+                              }
+                            },
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+                          }
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+                              "name": "_ownedTokens",
+                              "nodeType": "Identifier",
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+                              "referencedDeclaration": 981,
+                              "src": "31319:12:1",
+                              "typeDescriptions": {
+                                "typeIdentifier": "t_mapping$_t_address_$_t_array$_t_uint256_$dyn_storage_$",
+                                "typeString": "mapping(address => uint256[] storage ref)"
+                              }
+                            },
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+                              "src": "31332:4:1",
+                              "typeDescriptions": {
+                                "typeIdentifier": "t_address",
+                                "typeString": "address"
+                              }
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+                            "typeIdentifier": "t_uint256",
+                            "typeString": "uint256"
+                          }
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+                      },
+                      {
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+                                "src": "31368:12:1",
+                                "typeDescriptions": {
+                                  "typeIdentifier": "t_mapping$_t_address_$_t_array$_t_uint256_$dyn_storage_$",
+                                  "typeString": "mapping(address => uint256[] storage ref)"
+                                }
+                              },
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+                                "typeDescriptions": {
+                                  "typeIdentifier": "t_address",
+                                  "typeString": "address"
+                                }
+                              },
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+                              "isPure": false,
+                              "lValueRequested": false,
+                              "nodeType": "IndexAccess",
+                              "src": "31368:18:1",
+                              "typeDescriptions": {
+                                "typeIdentifier": "t_array$_t_uint256_$dyn_storage",
+                                "typeString": "uint256[] storage ref"
+                              }
+                            },
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+                            "indexExpression": {
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+                              "name": "tokenIndex",
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+                              "referencedDeclaration": 1213,
+                              "src": "31387:10:1",
+                              "typeDescriptions": {
+                                "typeIdentifier": "t_uint256",
+                                "typeString": "uint256"
+                              }
+                            },
+                            "isConstant": false,
+                            "isLValue": true,
+                            "isPure": false,
+                            "lValueRequested": true,
+                            "nodeType": "IndexAccess",
+                            "src": "31368:30:1",
+                            "typeDescriptions": {
+                              "typeIdentifier": "t_uint256",
+                              "typeString": "uint256"
+                            }
+                          },
+                          "nodeType": "Assignment",
+                          "operator": "=",
+                          "rightHandSide": {
+                            "argumentTypes": null,
+                            "id": 1234,
+                            "name": "lastTokenId",
+                            "nodeType": "Identifier",
+                            "overloadedDeclarations": [],
+                            "referencedDeclaration": 1222,
+                            "src": "31401:11:1",
+                            "typeDescriptions": {
+                              "typeIdentifier": "t_uint256",
+                              "typeString": "uint256"
+                            }
+                          },
+                          "src": "31368:44:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_uint256",
+                            "typeString": "uint256"
+                          }
+                        },
+                        "id": 1236,
+                        "nodeType": "ExpressionStatement",
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+                      },
+                      {
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+                          "id": 1241,
+                          "isConstant": false,
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+                          "leftHandSide": {
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+                            "baseExpression": {
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+                              "id": 1237,
+                              "name": "_ownedTokensIndex",
+                              "nodeType": "Identifier",
+                              "overloadedDeclarations": [],
+                              "referencedDeclaration": 985,
+                              "src": "31484:17:1",
+                              "typeDescriptions": {
+                                "typeIdentifier": "t_mapping$_t_uint256_$_t_uint256_$",
+                                "typeString": "mapping(uint256 => uint256)"
+                              }
+                            },
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+                              "id": 1238,
+                              "name": "lastTokenId",
+                              "nodeType": "Identifier",
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+                              "referencedDeclaration": 1222,
+                              "src": "31502:11:1",
+                              "typeDescriptions": {
+                                "typeIdentifier": "t_uint256",
+                                "typeString": "uint256"
+                              }
+                            },
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+                            "isPure": false,
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+                            "nodeType": "IndexAccess",
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+                            "typeDescriptions": {
+                              "typeIdentifier": "t_uint256",
+                              "typeString": "uint256"
+                            }
+                          },
+                          "nodeType": "Assignment",
+                          "operator": "=",
+                          "rightHandSide": {
+                            "argumentTypes": null,
+                            "id": 1240,
+                            "name": "tokenIndex",
+                            "nodeType": "Identifier",
+                            "overloadedDeclarations": [],
+                            "referencedDeclaration": 1213,
+                            "src": "31517:10:1",
+                            "typeDescriptions": {
+                              "typeIdentifier": "t_uint256",
+                              "typeString": "uint256"
+                            }
+                          },
+                          "src": "31484:43:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_uint256",
+                            "typeString": "uint256"
+                          }
+                        },
+                        "id": 1242,
+                        "nodeType": "ExpressionStatement",
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+                      }
+                    ]
+                  }
+                },
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+                    "isConstant": false,
+                    "isLValue": false,
+                    "isPure": false,
+                    "lValueRequested": false,
+                    "nodeType": "UnaryOperation",
+                    "operator": "--",
+                    "prefix": false,
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+                      "expression": {
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+                        "baseExpression": {
+                          "argumentTypes": null,
+                          "id": 1245,
+                          "name": "_ownedTokens",
+                          "nodeType": "Identifier",
+                          "overloadedDeclarations": [],
+                          "referencedDeclaration": 981,
+                          "src": "31658:12:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_mapping$_t_address_$_t_array$_t_uint256_$dyn_storage_$",
+                            "typeString": "mapping(address => uint256[] storage ref)"
+                          }
+                        },
+                        "id": 1247,
+                        "indexExpression": {
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+                          "name": "from",
+                          "nodeType": "Identifier",
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+                          "src": "31671:4:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_address",
+                            "typeString": "address"
+                          }
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+                        "isConstant": false,
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+                        "isPure": false,
+                        "lValueRequested": false,
+                        "nodeType": "IndexAccess",
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+                        "typeDescriptions": {
+                          "typeIdentifier": "t_array$_t_uint256_$dyn_storage",
+                          "typeString": "uint256[] storage ref"
+                        }
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+                      "isLValue": true,
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+                      "nodeType": "MemberAccess",
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+                      "src": "31658:25:1",
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+                    }
+                  },
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+                  "nodeType": "ExpressionStatement",
+                  "src": "31658:27:1"
+                }
+              ]
+            },
+            "documentation": "@dev Private function to remove a token from this extension's ownership-tracking data structures. Note that\nwhile the token is not assigned a new owner, the _ownedTokensIndex mapping is _not_ updated: this allows for\ngas optimizations e.g. when performing a transfer operation (avoiding double writes).\nThis has O(1) time complexity, but alters the order of the _ownedTokens array.\n@param from address representing the previous owner of the given token ID\n@param tokenId uint256 ID of the token to be removed from the tokens list of the given address",
+            "id": 1252,
+            "implemented": true,
+            "kind": "function",
+            "modifiers": [],
+            "name": "_removeTokenFromOwnerEnumeration",
+            "nodeType": "FunctionDefinition",
+            "parameters": {
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+              "nodeType": "ParameterList",
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+                  "id": 1197,
+                  "name": "from",
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+                  "scope": 1252,
+                  "src": "30815:12:1",
+                  "stateVariable": false,
+                  "storageLocation": "default",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_address",
+                    "typeString": "address"
+                  },
+                  "typeName": {
+                    "id": 1196,
+                    "name": "address",
+                    "nodeType": "ElementaryTypeName",
+                    "src": "30815:7:1",
+                    "stateMutability": "nonpayable",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_address",
+                      "typeString": "address"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                },
+                {
+                  "constant": false,
+                  "id": 1199,
+                  "name": "tokenId",
+                  "nodeType": "VariableDeclaration",
+                  "scope": 1252,
+                  "src": "30829:15:1",
+                  "stateVariable": false,
+                  "storageLocation": "default",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_uint256",
+                    "typeString": "uint256"
+                  },
+                  "typeName": {
+                    "id": 1198,
+                    "name": "uint256",
+                    "nodeType": "ElementaryTypeName",
+                    "src": "30829:7:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_uint256",
+                      "typeString": "uint256"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                }
+              ],
+              "src": "30814:31:1"
+            },
+            "returnParameters": {
+              "id": 1201,
+              "nodeType": "ParameterList",
+              "parameters": [],
+              "src": "30854:0:1"
+            },
+            "scope": 1302,
+            "src": "30773:1128:1",
+            "stateMutability": "nonpayable",
+            "superFunction": null,
+            "visibility": "private"
+          },
+          {
+            "body": {
+              "id": 1300,
+              "nodeType": "Block",
+              "src": "32260:993:1",
+              "statements": [
+                {
+                  "assignments": [
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+                  ],
+                  "declarations": [
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+                      "id": 1258,
+                      "name": "lastTokenIndex",
+                      "nodeType": "VariableDeclaration",
+                      "scope": 1300,
+                      "src": "32438:22:1",
+                      "stateVariable": false,
+                      "storageLocation": "default",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_uint256",
+                        "typeString": "uint256"
+                      },
+                      "typeName": {
+                        "id": 1257,
+                        "name": "uint256",
+                        "nodeType": "ElementaryTypeName",
+                        "src": "32438:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      },
+                      "value": null,
+                      "visibility": "internal"
+                    }
+                  ],
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+                  "initialValue": {
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+                    "arguments": [
+                      {
+                        "argumentTypes": null,
+                        "hexValue": "31",
+                        "id": 1262,
+                        "isConstant": false,
+                        "isLValue": false,
+                        "isPure": true,
+                        "kind": "number",
+                        "lValueRequested": false,
+                        "nodeType": "Literal",
+                        "src": "32485:1:1",
+                        "subdenomination": null,
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_rational_1_by_1",
+                          "typeString": "int_const 1"
+                        },
+                        "value": "1"
+                      }
+                    ],
+                    "expression": {
+                      "argumentTypes": [
+                        {
+                          "typeIdentifier": "t_rational_1_by_1",
+                          "typeString": "int_const 1"
+                        }
+                      ],
+                      "expression": {
+                        "argumentTypes": null,
+                        "expression": {
+                          "argumentTypes": null,
+                          "id": 1259,
+                          "name": "_allTokens",
+                          "nodeType": "Identifier",
+                          "overloadedDeclarations": [],
+                          "referencedDeclaration": 988,
+                          "src": "32463:10:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_array$_t_uint256_$dyn_storage",
+                            "typeString": "uint256[] storage ref"
+                          }
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+                        "isLValue": true,
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+                        "lValueRequested": false,
+                        "memberName": "length",
+                        "nodeType": "MemberAccess",
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+                        "src": "32463:17:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
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+                      "memberName": "sub",
+                      "nodeType": "MemberAccess",
+                      "referencedDeclaration": 190,
+                      "src": "32463:21:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_function_internal_pure$_t_uint256_$_t_uint256_$returns$_t_uint256_$bound_to$_t_uint256_$",
+                        "typeString": "function (uint256,uint256) pure returns (uint256)"
+                      }
+                    },
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+                    "isConstant": false,
+                    "isLValue": false,
+                    "isPure": false,
+                    "kind": "functionCall",
+                    "lValueRequested": false,
+                    "names": [],
+                    "nodeType": "FunctionCall",
+                    "src": "32463:24:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_uint256",
+                      "typeString": "uint256"
+                    }
+                  },
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+                  "src": "32438:49:1"
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+                      "name": "tokenIndex",
+                      "nodeType": "VariableDeclaration",
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+                      "src": "32497:18:1",
+                      "stateVariable": false,
+                      "storageLocation": "default",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_uint256",
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+                        "name": "uint256",
+                        "nodeType": "ElementaryTypeName",
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+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
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+                  "initialValue": {
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+                      "id": 1267,
+                      "name": "_allTokensIndex",
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+                      "src": "32518:15:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_mapping$_t_uint256_$_t_uint256_$",
+                        "typeString": "mapping(uint256 => uint256)"
+                      }
+                    },
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+                    "indexExpression": {
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+                      "id": 1268,
+                      "name": "tokenId",
+                      "nodeType": "Identifier",
+                      "overloadedDeclarations": [],
+                      "referencedDeclaration": 1254,
+                      "src": "32534:7:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_uint256",
+                        "typeString": "uint256"
+                      }
+                    },
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+                    "isPure": false,
+                    "lValueRequested": false,
+                    "nodeType": "IndexAccess",
+                    "src": "32518:24:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_uint256",
+                      "typeString": "uint256"
+                    }
+                  },
+                  "nodeType": "VariableDeclarationStatement",
+                  "src": "32497:45:1"
+                },
+                {
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+                  ],
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+                    {
+                      "constant": false,
+                      "id": 1272,
+                      "name": "lastTokenId",
+                      "nodeType": "VariableDeclaration",
+                      "scope": 1300,
+                      "src": "32864:19:1",
+                      "stateVariable": false,
+                      "storageLocation": "default",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_uint256",
+                        "typeString": "uint256"
+                      },
+                      "typeName": {
+                        "id": 1271,
+                        "name": "uint256",
+                        "nodeType": "ElementaryTypeName",
+                        "src": "32864:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
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+                      "visibility": "internal"
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+                      "src": "32886:10:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_array$_t_uint256_$dyn_storage",
+                        "typeString": "uint256[] storage ref"
+                      }
+                    },
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+                      "src": "32897:14:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_uint256",
+                        "typeString": "uint256"
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+                    },
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+                    "isPure": false,
+                    "lValueRequested": false,
+                    "nodeType": "IndexAccess",
+                    "src": "32886:26:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_uint256",
+                      "typeString": "uint256"
+                    }
+                  },
+                  "nodeType": "VariableDeclarationStatement",
+                  "src": "32864:48:1"
+                },
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+                              "src": "36416:10:1",
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+                          "typeString": "address"
+                        },
+                        {
+                          "typeIdentifier": "t_bool",
+                          "typeString": "bool"
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+                        "src": "17734:4:1",
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+                          "typeString": "address"
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+                          "typeString": "address"
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+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        },
+                        {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
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+                      "name": "_transferFrom",
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+                        "name": "tokenId",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 1113,
+                        "src": "28921:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
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+                      "isConstant": false,
+                      "isLValue": true,
+                      "isPure": false,
+                      "lValueRequested": true,
+                      "nodeType": "IndexAccess",
+                      "src": "28903:26:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_uint256",
+                        "typeString": "uint256"
+                      }
+                    },
+                    "nodeType": "Assignment",
+                    "operator": "=",
+                    "rightHandSide": {
+                      "argumentTypes": null,
+                      "hexValue": "30",
+                      "id": 1131,
+                      "isConstant": false,
+                      "isLValue": false,
+                      "isPure": true,
+                      "kind": "number",
+                      "lValueRequested": false,
+                      "nodeType": "Literal",
+                      "src": "28932:1:1",
+                      "subdenomination": null,
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_rational_0_by_1",
+                        "typeString": "int_const 0"
+                      },
+                      "value": "0"
+                    },
+                    "src": "28903:30:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_uint256",
+                      "typeString": "uint256"
+                    }
+                  },
+                  "id": 1133,
+                  "nodeType": "ExpressionStatement",
+                  "src": "28903:30:1"
+                },
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+                    "arguments": [
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+                        "id": 1135,
+                        "name": "tokenId",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 1113,
+                        "src": "28981:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      }
+                    ],
+                    "expression": {
+                      "argumentTypes": [
+                        {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      ],
+                      "id": 1134,
+                      "name": "_removeTokenFromAllTokensEnumeration",
+                      "nodeType": "Identifier",
+                      "overloadedDeclarations": [],
+                      "referencedDeclaration": 1301,
+                      "src": "28944:36:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_function_internal_nonpayable$_t_uint256_$returns$__$",
+                        "typeString": "function (uint256)"
+                      }
+                    },
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+                    "isConstant": false,
+                    "isLValue": false,
+                    "isPure": false,
+                    "kind": "functionCall",
+                    "lValueRequested": false,
+                    "names": [],
+                    "nodeType": "FunctionCall",
+                    "src": "28944:45:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_tuple$__$",
+                      "typeString": "tuple()"
+                    }
+                  },
+                  "id": 1137,
+                  "nodeType": "ExpressionStatement",
+                  "src": "28944:45:1"
+                }
+              ]
+            },
+            "documentation": "@dev Internal function to burn a specific token.\nReverts if the token does not exist.\nDeprecated, use _burn(uint256) instead.\n@param owner owner of the token to burn\n@param tokenId uint256 ID of the token being burned",
+            "id": 1139,
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+            "kind": "function",
+            "modifiers": [],
+            "name": "_burn",
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+              "nodeType": "ParameterList",
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+                  "id": 1111,
+                  "name": "owner",
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+                  "scope": 1139,
+                  "src": "28647:13:1",
+                  "stateVariable": false,
+                  "storageLocation": "default",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_address",
+                    "typeString": "address"
+                  },
+                  "typeName": {
+                    "id": 1110,
+                    "name": "address",
+                    "nodeType": "ElementaryTypeName",
+                    "src": "28647:7:1",
+                    "stateMutability": "nonpayable",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_address",
+                      "typeString": "address"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                },
+                {
+                  "constant": false,
+                  "id": 1113,
+                  "name": "tokenId",
+                  "nodeType": "VariableDeclaration",
+                  "scope": 1139,
+                  "src": "28662:15:1",
+                  "stateVariable": false,
+                  "storageLocation": "default",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_uint256",
+                    "typeString": "uint256"
+                  },
+                  "typeName": {
+                    "id": 1112,
+                    "name": "uint256",
+                    "nodeType": "ElementaryTypeName",
+                    "src": "28662:7:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_uint256",
+                      "typeString": "uint256"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                }
+              ],
+              "src": "28646:32:1"
+            },
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+              "id": 1115,
+              "nodeType": "ParameterList",
+              "parameters": [],
+              "src": "28688:0:1"
+            },
+            "scope": 1302,
+            "src": "28632:364:1",
+            "stateMutability": "nonpayable",
+            "superFunction": 811,
+            "visibility": "internal"
+          },
+          {
+            "body": {
+              "id": 1151,
+              "nodeType": "Block",
+              "src": "29282:43:1",
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+                {
+                  "expression": {
+                    "argumentTypes": null,
+                    "baseExpression": {
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+                      "id": 1147,
+                      "name": "_ownedTokens",
+                      "nodeType": "Identifier",
+                      "overloadedDeclarations": [],
+                      "referencedDeclaration": 981,
+                      "src": "29299:12:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_mapping$_t_address_$_t_array$_t_uint256_$dyn_storage_$",
+                        "typeString": "mapping(address => uint256[] storage ref)"
+                      }
+                    },
+                    "id": 1149,
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+                      "name": "owner",
+                      "nodeType": "Identifier",
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+                      "referencedDeclaration": 1141,
+                      "src": "29312:5:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_address",
+                        "typeString": "address"
+                      }
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+                    "isLValue": true,
+                    "isPure": false,
+                    "lValueRequested": false,
+                    "nodeType": "IndexAccess",
+                    "src": "29299:19:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_array$_t_uint256_$dyn_storage",
+                      "typeString": "uint256[] storage ref"
+                    }
+                  },
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+                  "id": 1150,
+                  "nodeType": "Return",
+                  "src": "29292:26:1"
+                }
+              ]
+            },
+            "documentation": "@dev Gets the list of token IDs of the requested owner.\n@param owner address owning the tokens\n@return uint256[] List of token IDs owned by the requested address",
+            "id": 1152,
+            "implemented": true,
+            "kind": "function",
+            "modifiers": [],
+            "name": "_tokensOfOwner",
+            "nodeType": "FunctionDefinition",
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+              "nodeType": "ParameterList",
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+                  "name": "owner",
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+                  "src": "29225:13:1",
+                  "stateVariable": false,
+                  "storageLocation": "default",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_address",
+                    "typeString": "address"
+                  },
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+                    "name": "address",
+                    "nodeType": "ElementaryTypeName",
+                    "src": "29225:7:1",
+                    "stateMutability": "nonpayable",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_address",
+                      "typeString": "address"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                }
+              ],
+              "src": "29224:15:1"
+            },
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+              "nodeType": "ParameterList",
+              "parameters": [
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+                  "id": 1145,
+                  "name": "",
+                  "nodeType": "VariableDeclaration",
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+                  "src": "29263:17:1",
+                  "stateVariable": false,
+                  "storageLocation": "storage",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_array$_t_uint256_$dyn_storage_ptr",
+                    "typeString": "uint256[]"
+                  },
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+                    "baseType": {
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+                      "name": "uint256",
+                      "nodeType": "ElementaryTypeName",
+                      "src": "29263:7:1",
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+                        "typeIdentifier": "t_uint256",
+                        "typeString": "uint256"
+                      }
+                    },
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+                    "length": null,
+                    "nodeType": "ArrayTypeName",
+                    "src": "29263:9:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_array$_t_uint256_$dyn_storage_ptr",
+                      "typeString": "uint256[]"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                }
+              ],
+              "src": "29262:19:1"
+            },
+            "scope": 1302,
+            "src": "29201:124:1",
+            "stateMutability": "view",
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+            "visibility": "internal"
+          },
+          {
+            "body": {
+              "id": 1175,
+              "nodeType": "Block",
+              "src": "29693:109:1",
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+                        "id": 1159,
+                        "name": "_ownedTokensIndex",
+                        "nodeType": "Identifier",
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+                        "referencedDeclaration": 985,
+                        "src": "29703:17:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_mapping$_t_uint256_$_t_uint256_$",
+                          "typeString": "mapping(uint256 => uint256)"
+                        }
+                      },
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+                      "indexExpression": {
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+                        "id": 1160,
+                        "name": "tokenId",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 1156,
+                        "src": "29721:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
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+                      "isLValue": true,
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+                      "lValueRequested": true,
+                      "nodeType": "IndexAccess",
+                      "src": "29703:26:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_uint256",
+                        "typeString": "uint256"
+                      }
+                    },
+                    "nodeType": "Assignment",
+                    "operator": "=",
+                    "rightHandSide": {
+                      "argumentTypes": null,
+                      "expression": {
+                        "argumentTypes": null,
+                        "baseExpression": {
+                          "argumentTypes": null,
+                          "id": 1162,
+                          "name": "_ownedTokens",
+                          "nodeType": "Identifier",
+                          "overloadedDeclarations": [],
+                          "referencedDeclaration": 981,
+                          "src": "29732:12:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_mapping$_t_address_$_t_array$_t_uint256_$dyn_storage_$",
+                            "typeString": "mapping(address => uint256[] storage ref)"
+                          }
+                        },
+                        "id": 1164,
+                        "indexExpression": {
+                          "argumentTypes": null,
+                          "id": 1163,
+                          "name": "to",
+                          "nodeType": "Identifier",
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+                          "referencedDeclaration": 1154,
+                          "src": "29745:2:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_address",
+                            "typeString": "address"
+                          }
+                        },
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+                        "isLValue": true,
+                        "isPure": false,
+                        "lValueRequested": false,
+                        "nodeType": "IndexAccess",
+                        "src": "29732:16:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_array$_t_uint256_$dyn_storage",
+                          "typeString": "uint256[] storage ref"
+                        }
+                      },
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+                      "isLValue": true,
+                      "isPure": false,
+                      "lValueRequested": false,
+                      "memberName": "length",
+                      "nodeType": "MemberAccess",
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+                      "src": "29732:23:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_uint256",
+                        "typeString": "uint256"
+                      }
+                    },
+                    "src": "29703:52:1",
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+                      "typeIdentifier": "t_uint256",
+                      "typeString": "uint256"
+                    }
+                  },
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+                  "nodeType": "ExpressionStatement",
+                  "src": "29703:52:1"
+                },
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+                        "id": 1172,
+                        "name": "tokenId",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 1156,
+                        "src": "29787:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      }
+                    ],
+                    "expression": {
+                      "argumentTypes": [
+                        {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      ],
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+                        "baseExpression": {
+                          "argumentTypes": null,
+                          "id": 1168,
+                          "name": "_ownedTokens",
+                          "nodeType": "Identifier",
+                          "overloadedDeclarations": [],
+                          "referencedDeclaration": 981,
+                          "src": "29765:12:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_mapping$_t_address_$_t_array$_t_uint256_$dyn_storage_$",
+                            "typeString": "mapping(address => uint256[] storage ref)"
+                          }
+                        },
+                        "id": 1170,
+                        "indexExpression": {
+                          "argumentTypes": null,
+                          "id": 1169,
+                          "name": "to",
+                          "nodeType": "Identifier",
+                          "overloadedDeclarations": [],
+                          "referencedDeclaration": 1154,
+                          "src": "29778:2:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_address",
+                            "typeString": "address"
+                          }
+                        },
+                        "isConstant": false,
+                        "isLValue": true,
+                        "isPure": false,
+                        "lValueRequested": false,
+                        "nodeType": "IndexAccess",
+                        "src": "29765:16:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_array$_t_uint256_$dyn_storage",
+                          "typeString": "uint256[] storage ref"
+                        }
+                      },
+                      "id": 1171,
+                      "isConstant": false,
+                      "isLValue": false,
+                      "isPure": false,
+                      "lValueRequested": false,
+                      "memberName": "push",
+                      "nodeType": "MemberAccess",
+                      "referencedDeclaration": null,
+                      "src": "29765:21:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_function_arraypush_nonpayable$_t_uint256_$returns$_t_uint256_$",
+                        "typeString": "function (uint256) returns (uint256)"
+                      }
+                    },
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+                    "isConstant": false,
+                    "isLValue": false,
+                    "isPure": false,
+                    "kind": "functionCall",
+                    "lValueRequested": false,
+                    "names": [],
+                    "nodeType": "FunctionCall",
+                    "src": "29765:30:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_uint256",
+                      "typeString": "uint256"
+                    }
+                  },
+                  "id": 1174,
+                  "nodeType": "ExpressionStatement",
+                  "src": "29765:30:1"
+                }
+              ]
+            },
+            "documentation": "@dev Private function to add a token to this extension's ownership-tracking data structures.\n@param to address representing the new owner of the given token ID\n@param tokenId uint256 ID of the token to be added to the tokens list of the given address",
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+            "kind": "function",
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+            "name": "_addTokenToOwnerEnumeration",
+            "nodeType": "FunctionDefinition",
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+              "nodeType": "ParameterList",
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+                  "src": "29656:10:1",
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+                  "storageLocation": "default",
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+                    "typeIdentifier": "t_address",
+                    "typeString": "address"
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+                    "id": 1153,
+                    "name": "address",
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+                      "typeIdentifier": "t_address",
+                      "typeString": "address"
+                    }
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+                  "visibility": "internal"
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+                  "src": "29668:15:1",
+                  "stateVariable": false,
+                  "storageLocation": "default",
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+                    "name": "uint256",
+                    "nodeType": "ElementaryTypeName",
+                    "src": "29668:7:1",
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+                      "typeIdentifier": "t_uint256",
+                      "typeString": "uint256"
+                    }
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+                  "value": null,
+                  "visibility": "internal"
+                }
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+              "src": "29655:29:1"
+            },
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+              "src": "29693:0:1"
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+            "src": "29619:183:1",
+            "stateMutability": "nonpayable",
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+            "visibility": "private"
+          },
+          {
+            "body": {
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+              "src": "30063:95:1",
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+                    "id": 1186,
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+                    "isLValue": false,
+                    "isPure": false,
+                    "lValueRequested": false,
+                    "leftHandSide": {
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+                      "baseExpression": {
+                        "argumentTypes": null,
+                        "id": 1181,
+                        "name": "_allTokensIndex",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 992,
+                        "src": "30073:15:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_mapping$_t_uint256_$_t_uint256_$",
+                          "typeString": "mapping(uint256 => uint256)"
+                        }
+                      },
+                      "id": 1183,
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+                        "id": 1182,
+                        "name": "tokenId",
+                        "nodeType": "Identifier",
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+                        "referencedDeclaration": 1178,
+                        "src": "30089:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
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+                      "nodeType": "IndexAccess",
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+                        "typeIdentifier": "t_uint256",
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+                      }
+                    },
+                    "nodeType": "Assignment",
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+                        "id": 1184,
+                        "name": "_allTokens",
+                        "nodeType": "Identifier",
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+                        "src": "30100:10:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_array$_t_uint256_$dyn_storage",
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+                        }
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+                      "isConstant": false,
+                      "isLValue": true,
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+                      "src": "30100:17:1",
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+                        "typeIdentifier": "t_uint256",
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+                        "id": 1191,
+                        "name": "tokenId",
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+                        "referencedDeclaration": 1178,
+                        "src": "30143:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
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+                    ],
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+                          "typeString": "uint256"
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+                      "expression": {
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+                        "id": 1188,
+                        "name": "_allTokens",
+                        "nodeType": "Identifier",
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+                        "referencedDeclaration": 988,
+                        "src": "30127:10:1",
+                        "typeDescriptions": {
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+            "documentation": "@dev Private function to remove a token from this extension's ownership-tracking data structures. Note that\nwhile the token is not assigned a new owner, the _ownedTokensIndex mapping is _not_ updated: this allows for\ngas optimizations e.g. when performing a transfer operation (avoiding double writes).\nThis has O(1) time complexity, but alters the order of the _ownedTokens array.\n@param from address representing the previous owner of the given token ID\n@param tokenId uint256 ID of the token to be removed from the tokens list of the given address",
+            "id": 1252,
+            "implemented": true,
+            "kind": "function",
+            "modifiers": [],
+            "name": "_removeTokenFromOwnerEnumeration",
+            "nodeType": "FunctionDefinition",
+            "parameters": {
+              "id": 1200,
+              "nodeType": "ParameterList",
+              "parameters": [
+                {
+                  "constant": false,
+                  "id": 1197,
+                  "name": "from",
+                  "nodeType": "VariableDeclaration",
+                  "scope": 1252,
+                  "src": "30815:12:1",
+                  "stateVariable": false,
+                  "storageLocation": "default",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_address",
+                    "typeString": "address"
+                  },
+                  "typeName": {
+                    "id": 1196,
+                    "name": "address",
+                    "nodeType": "ElementaryTypeName",
+                    "src": "30815:7:1",
+                    "stateMutability": "nonpayable",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_address",
+                      "typeString": "address"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                },
+                {
+                  "constant": false,
+                  "id": 1199,
+                  "name": "tokenId",
+                  "nodeType": "VariableDeclaration",
+                  "scope": 1252,
+                  "src": "30829:15:1",
+                  "stateVariable": false,
+                  "storageLocation": "default",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_uint256",
+                    "typeString": "uint256"
+                  },
+                  "typeName": {
+                    "id": 1198,
+                    "name": "uint256",
+                    "nodeType": "ElementaryTypeName",
+                    "src": "30829:7:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_uint256",
+                      "typeString": "uint256"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                }
+              ],
+              "src": "30814:31:1"
+            },
+            "returnParameters": {
+              "id": 1201,
+              "nodeType": "ParameterList",
+              "parameters": [],
+              "src": "30854:0:1"
+            },
+            "scope": 1302,
+            "src": "30773:1128:1",
+            "stateMutability": "nonpayable",
+            "superFunction": null,
+            "visibility": "private"
+          },
+          {
+            "body": {
+              "id": 1300,
+              "nodeType": "Block",
+              "src": "32260:993:1",
+              "statements": [
+                {
+                  "assignments": [
+                    1258
+                  ],
+                  "declarations": [
+                    {
+                      "constant": false,
+                      "id": 1258,
+                      "name": "lastTokenIndex",
+                      "nodeType": "VariableDeclaration",
+                      "scope": 1300,
+                      "src": "32438:22:1",
+                      "stateVariable": false,
+                      "storageLocation": "default",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_uint256",
+                        "typeString": "uint256"
+                      },
+                      "typeName": {
+                        "id": 1257,
+                        "name": "uint256",
+                        "nodeType": "ElementaryTypeName",
+                        "src": "32438:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      },
+                      "value": null,
+                      "visibility": "internal"
+                    }
+                  ],
+                  "id": 1264,
+                  "initialValue": {
+                    "argumentTypes": null,
+                    "arguments": [
+                      {
+                        "argumentTypes": null,
+                        "hexValue": "31",
+                        "id": 1262,
+                        "isConstant": false,
+                        "isLValue": false,
+                        "isPure": true,
+                        "kind": "number",
+                        "lValueRequested": false,
+                        "nodeType": "Literal",
+                        "src": "32485:1:1",
+                        "subdenomination": null,
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_rational_1_by_1",
+                          "typeString": "int_const 1"
+                        },
+                        "value": "1"
+                      }
+                    ],
+                    "expression": {
+                      "argumentTypes": [
+                        {
+                          "typeIdentifier": "t_rational_1_by_1",
+                          "typeString": "int_const 1"
+                        }
+                      ],
+                      "expression": {
+                        "argumentTypes": null,
+                        "expression": {
+                          "argumentTypes": null,
+                          "id": 1259,
+                          "name": "_allTokens",
+                          "nodeType": "Identifier",
+                          "overloadedDeclarations": [],
+                          "referencedDeclaration": 988,
+                          "src": "32463:10:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_array$_t_uint256_$dyn_storage",
+                            "typeString": "uint256[] storage ref"
+                          }
+                        },
+                        "id": 1260,
+                        "isConstant": false,
+                        "isLValue": true,
+                        "isPure": false,
+                        "lValueRequested": false,
+                        "memberName": "length",
+                        "nodeType": "MemberAccess",
+                        "referencedDeclaration": null,
+                        "src": "32463:17:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      },
+                      "id": 1261,
+                      "isConstant": false,
+                      "isLValue": false,
+                      "isPure": false,
+                      "lValueRequested": false,
+                      "memberName": "sub",
+                      "nodeType": "MemberAccess",
+                      "referencedDeclaration": 190,
+                      "src": "32463:21:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_function_internal_pure$_t_uint256_$_t_uint256_$returns$_t_uint256_$bound_to$_t_uint256_$",
+                        "typeString": "function (uint256,uint256) pure returns (uint256)"
+                      }
+                    },
+                    "id": 1263,
+                    "isConstant": false,
+                    "isLValue": false,
+                    "isPure": false,
+                    "kind": "functionCall",
+                    "lValueRequested": false,
+                    "names": [],
+                    "nodeType": "FunctionCall",
+                    "src": "32463:24:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_uint256",
+                      "typeString": "uint256"
+                    }
+                  },
+                  "nodeType": "VariableDeclarationStatement",
+                  "src": "32438:49:1"
+                },
+                {
+                  "assignments": [
+                    1266
+                  ],
+                  "declarations": [
+                    {
+                      "constant": false,
+                      "id": 1266,
+                      "name": "tokenIndex",
+                      "nodeType": "VariableDeclaration",
+                      "scope": 1300,
+                      "src": "32497:18:1",
+                      "stateVariable": false,
+                      "storageLocation": "default",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_uint256",
+                        "typeString": "uint256"
+                      },
+                      "typeName": {
+                        "id": 1265,
+                        "name": "uint256",
+                        "nodeType": "ElementaryTypeName",
+                        "src": "32497:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      },
+                      "value": null,
+                      "visibility": "internal"
+                    }
+                  ],
+                  "id": 1270,
+                  "initialValue": {
+                    "argumentTypes": null,
+                    "baseExpression": {
+                      "argumentTypes": null,
+                      "id": 1267,
+                      "name": "_allTokensIndex",
+                      "nodeType": "Identifier",
+                      "overloadedDeclarations": [],
+                      "referencedDeclaration": 992,
+                      "src": "32518:15:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_mapping$_t_uint256_$_t_uint256_$",
+                        "typeString": "mapping(uint256 => uint256)"
+                      }
+                    },
+                    "id": 1269,
+                    "indexExpression": {
+                      "argumentTypes": null,
+                      "id": 1268,
+                      "name": "tokenId",
+                      "nodeType": "Identifier",
+                      "overloadedDeclarations": [],
+                      "referencedDeclaration": 1254,
+                      "src": "32534:7:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_uint256",
+                        "typeString": "uint256"
+                      }
+                    },
+                    "isConstant": false,
+                    "isLValue": true,
+                    "isPure": false,
+                    "lValueRequested": false,
+                    "nodeType": "IndexAccess",
+                    "src": "32518:24:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_uint256",
+                      "typeString": "uint256"
+                    }
+                  },
+                  "nodeType": "VariableDeclarationStatement",
+                  "src": "32497:45:1"
+                },
+                {
+                  "assignments": [
+                    1272
+                  ],
+                  "declarations": [
+                    {
+                      "constant": false,
+                      "id": 1272,
+                      "name": "lastTokenId",
+                      "nodeType": "VariableDeclaration",
+                      "scope": 1300,
+                      "src": "32864:19:1",
+                      "stateVariable": false,
+                      "storageLocation": "default",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_uint256",
+                        "typeString": "uint256"
+                      },
+                      "typeName": {
+                        "id": 1271,
+                        "name": "uint256",
+                        "nodeType": "ElementaryTypeName",
+                        "src": "32864:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      },
+                      "value": null,
+                      "visibility": "internal"
+                    }
+                  ],
+                  "id": 1276,
+                  "initialValue": {
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+                    "baseExpression": {
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+                      "name": "_allTokens",
+                      "nodeType": "Identifier",
+                      "overloadedDeclarations": [],
+                      "referencedDeclaration": 988,
+                      "src": "32886:10:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_array$_t_uint256_$dyn_storage",
+                        "typeString": "uint256[] storage ref"
+                      }
+                    },
+                    "id": 1275,
+                    "indexExpression": {
+                      "argumentTypes": null,
+                      "id": 1274,
+                      "name": "lastTokenIndex",
+                      "nodeType": "Identifier",
+                      "overloadedDeclarations": [],
+                      "referencedDeclaration": 1258,
+                      "src": "32897:14:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_uint256",
+                        "typeString": "uint256"
+                      }
+                    },
+                    "isConstant": false,
+                    "isLValue": true,
+                    "isPure": false,
+                    "lValueRequested": false,
+                    "nodeType": "IndexAccess",
+                    "src": "32886:26:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_uint256",
+                      "typeString": "uint256"
+                    }
+                  },
+                  "nodeType": "VariableDeclarationStatement",
+                  "src": "32864:48:1"
+                },
+                {
+                  "expression": {
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+                    "isLValue": false,
+                    "isPure": false,
+                    "lValueRequested": false,
+                    "leftHandSide": {
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+                      "baseExpression": {
+                        "argumentTypes": null,
+                        "id": 1277,
+                        "name": "_allTokens",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 988,
+                        "src": "32923:10:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_array$_t_uint256_$dyn_storage",
+                          "typeString": "uint256[] storage ref"
+                        }
+                      },
+                      "id": 1279,
+                      "indexExpression": {
+                        "argumentTypes": null,
+                        "id": 1278,
+                        "name": "tokenIndex",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 1266,
+                        "src": "32934:10:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      },
+                      "isConstant": false,
+                      "isLValue": true,
+                      "isPure": false,
+                      "lValueRequested": true,
+                      "nodeType": "IndexAccess",
+                      "src": "32923:22:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_uint256",
+                        "typeString": "uint256"
+                      }
+                    },
+                    "nodeType": "Assignment",
+                    "operator": "=",
+                    "rightHandSide": {
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+                      "id": 1280,
+                      "name": "lastTokenId",
+                      "nodeType": "Identifier",
+                      "overloadedDeclarations": [],
+                      "referencedDeclaration": 1272,
+                      "src": "32948:11:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_uint256",
+                        "typeString": "uint256"
+                      }
+                    },
+                    "src": "32923:36:1",
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+                      "typeIdentifier": "t_uint256",
+                      "typeString": "uint256"
+                    }
+                  },
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+                  "src": "32923:36:1"
+                },
+                {
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+                    "isLValue": false,
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+                    "leftHandSide": {
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+                      "baseExpression": {
+                        "argumentTypes": null,
+                        "id": 1283,
+                        "name": "_allTokensIndex",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 992,
+                        "src": "33027:15:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_mapping$_t_uint256_$_t_uint256_$",
+                          "typeString": "mapping(uint256 => uint256)"
+                        }
+                      },
+                      "id": 1285,
+                      "indexExpression": {
+                        "argumentTypes": null,
+                        "id": 1284,
+                        "name": "lastTokenId",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 1272,
+                        "src": "33043:11:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      },
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+                      "nodeType": "IndexAccess",
+                      "src": "33027:28:1",
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+                        "typeIdentifier": "t_uint256",
+                        "typeString": "uint256"
+                      }
+                    },
+                    "nodeType": "Assignment",
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+                      "name": "tokenIndex",
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+                      "src": "33058:10:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_uint256",
+                        "typeString": "uint256"
+                      }
+                    },
+                    "src": "33027:41:1",
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+                      "typeIdentifier": "t_uint256",
+                      "typeString": "uint256"
+                    }
+                  },
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+                  "src": "33027:41:1"
+                },
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+                    "isLValue": false,
+                    "isPure": false,
+                    "lValueRequested": false,
+                    "nodeType": "UnaryOperation",
+                    "operator": "--",
+                    "prefix": false,
+                    "src": "33189:19:1",
+                    "subExpression": {
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+                      "expression": {
+                        "argumentTypes": null,
+                        "id": 1289,
+                        "name": "_allTokens",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 988,
+                        "src": "33189:10:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_array$_t_uint256_$dyn_storage",
+                          "typeString": "uint256[] storage ref"
+                        }
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+                      "memberName": "length",
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+                      "src": "33189:17:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_uint256",
+                        "typeString": "uint256"
+                      }
+                    },
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+                      "typeIdentifier": "t_uint256",
+                      "typeString": "uint256"
+                    }
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+                  "nodeType": "ExpressionStatement",
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+                },
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+                      "baseExpression": {
+                        "argumentTypes": null,
+                        "id": 1294,
+                        "name": "_allTokensIndex",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 992,
+                        "src": "33218:15:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_mapping$_t_uint256_$_t_uint256_$",
+                          "typeString": "mapping(uint256 => uint256)"
+                        }
+                      },
+                      "id": 1296,
+                      "indexExpression": {
+                        "argumentTypes": null,
+                        "id": 1295,
+                        "name": "tokenId",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 1254,
+                        "src": "33234:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      },
+                      "isConstant": false,
+                      "isLValue": true,
+                      "isPure": false,
+                      "lValueRequested": true,
+                      "nodeType": "IndexAccess",
+                      "src": "33218:24:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_uint256",
+                        "typeString": "uint256"
+                      }
+                    },
+                    "nodeType": "Assignment",
+                    "operator": "=",
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+                      "argumentTypes": null,
+                      "hexValue": "30",
+                      "id": 1297,
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+                      "isLValue": false,
+                      "isPure": true,
+                      "kind": "number",
+                      "lValueRequested": false,
+                      "nodeType": "Literal",
+                      "src": "33245:1:1",
+                      "subdenomination": null,
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_rational_0_by_1",
+                        "typeString": "int_const 0"
+                      },
+                      "value": "0"
+                    },
+                    "src": "33218:28:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_uint256",
+                      "typeString": "uint256"
+                    }
+                  },
+                  "id": 1299,
+                  "nodeType": "ExpressionStatement",
+                  "src": "33218:28:1"
+                }
+              ]
+            },
+            "documentation": "@dev Private function to remove a token from this extension's token tracking data structures.\nThis has O(1) time complexity, but alters the order of the _allTokens array.\n@param tokenId uint256 ID of the token to be removed from the tokens list",
+            "id": 1301,
+            "implemented": true,
+            "kind": "function",
+            "modifiers": [],
+            "name": "_removeTokenFromAllTokensEnumeration",
+            "nodeType": "FunctionDefinition",
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+              "nodeType": "ParameterList",
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+                  "src": "32235:15:1",
+                  "stateVariable": false,
+                  "storageLocation": "default",
+                  "typeDescriptions": {
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+                    "name": "uint256",
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+                      "typeString": "uint256"
+                    }
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+                  "visibility": "internal"
+                }
+              ],
+              "src": "32234:17:1"
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+              "parameters": [],
+              "src": "32260:0:1"
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+            "stateMutability": "nonpayable",
+            "superFunction": null,
+            "visibility": "private"
+          }
+        ],
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+        "src": "24794:8461:1"
+      },
+      {
+        "id": 1303,
+        "literals": [
+          "solidity",
+          "^",
+          "0.5",
+          ".0"
+        ],
+        "nodeType": "PragmaDirective",
+        "src": "33324:23:1"
+      },
+      {
+        "baseContracts": [
+          {
+            "arguments": null,
+            "baseName": {
+              "contractScope": null,
+              "id": 1304,
+              "name": "IERC721",
+              "nodeType": "UserDefinedTypeName",
+              "referencedDeclaration": 124,
+              "src": "33512:7:1",
+              "typeDescriptions": {
+                "typeIdentifier": "t_contract$_IERC721_$124",
+                "typeString": "contract IERC721"
+              }
+            },
+            "id": 1305,
+            "nodeType": "InheritanceSpecifier",
+            "src": "33512:7:1"
+          }
+        ],
+        "contractDependencies": [
+          23,
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+        ],
+        "contractKind": "contract",
+        "documentation": "@title ERC-721 Non-Fungible Token Standard, optional metadata extension\n@dev See https://eips.ethereum.org/EIPS/eip-721",
+        "fullyImplemented": false,
+        "id": 1323,
+        "linearizedBaseContracts": [
+          1323,
+          124,
+          23
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+        "name": "IERC721Metadata",
+        "nodeType": "ContractDefinition",
+        "nodes": [
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+            "body": null,
+            "documentation": null,
+            "id": 1310,
+            "implemented": false,
+            "kind": "function",
+            "modifiers": [],
+            "name": "name",
+            "nodeType": "FunctionDefinition",
+            "parameters": {
+              "id": 1306,
+              "nodeType": "ParameterList",
+              "parameters": [],
+              "src": "33539:2:1"
+            },
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+              "nodeType": "ParameterList",
+              "parameters": [
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+                  "id": 1308,
+                  "name": "",
+                  "nodeType": "VariableDeclaration",
+                  "scope": 1310,
+                  "src": "33565:13:1",
+                  "stateVariable": false,
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+                          "isConstant": false,
+                          "isLValue": false,
+                          "isPure": false,
+                          "lValueRequested": false,
+                          "nodeType": "UnaryOperation",
+                          "operator": "delete",
+                          "prefix": true,
+                          "src": "36409:26:1",
+                          "subExpression": {
+                            "argumentTypes": null,
+                            "baseExpression": {
+                              "argumentTypes": null,
+                              "id": 1439,
+                              "name": "_tokenURIs",
+                              "nodeType": "Identifier",
+                              "overloadedDeclarations": [],
+                              "referencedDeclaration": 1338,
+                              "src": "36416:10:1",
+                              "typeDescriptions": {
+                                "typeIdentifier": "t_mapping$_t_uint256_$_t_string_storage_$",
+                                "typeString": "mapping(uint256 => string storage ref)"
+                              }
+                            },
+                            "id": 1441,
+                            "indexExpression": {
+                              "argumentTypes": null,
+                              "id": 1440,
+                              "name": "tokenId",
+                              "nodeType": "Identifier",
+                              "overloadedDeclarations": [],
+                              "referencedDeclaration": 1421,
+                              "src": "36427:7:1",
+                              "typeDescriptions": {
+                                "typeIdentifier": "t_uint256",
+                                "typeString": "uint256"
+                              }
+                            },
+                            "isConstant": false,
+                            "isLValue": true,
+                            "isPure": false,
+                            "lValueRequested": true,
+                            "nodeType": "IndexAccess",
+                            "src": "36416:19:1",
+                            "typeDescriptions": {
+                              "typeIdentifier": "t_string_storage",
+                              "typeString": "string storage ref"
+                            }
+                          },
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_tuple$__$",
+                            "typeString": "tuple()"
+                          }
+                        },
+                        "id": 1443,
+                        "nodeType": "ExpressionStatement",
+                        "src": "36409:26:1"
+                      }
+                    ]
+                  }
+                }
+              ]
+            },
+            "documentation": "@dev Internal function to burn a specific token.\nReverts if the token does not exist.\nDeprecated, use _burn(uint256) instead.\n@param owner owner of the token to burn\n@param tokenId uint256 ID of the token being burned by the msg.sender",
+            "id": 1447,
+            "implemented": true,
+            "kind": "function",
+            "modifiers": [],
+            "name": "_burn",
+            "nodeType": "FunctionDefinition",
+            "parameters": {
+              "id": 1422,
+              "nodeType": "ParameterList",
+              "parameters": [
+                {
+                  "constant": false,
+                  "id": 1419,
+                  "name": "owner",
+                  "nodeType": "VariableDeclaration",
+                  "scope": 1447,
+                  "src": "36227:13:1",
+                  "stateVariable": false,
+                  "storageLocation": "default",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_address",
+                    "typeString": "address"
+                  },
+                  "typeName": {
+                    "id": 1418,
+                    "name": "address",
+                    "nodeType": "ElementaryTypeName",
+                    "src": "36227:7:1",
+                    "stateMutability": "nonpayable",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_address",
+                      "typeString": "address"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                },
+                {
+                  "constant": false,
+                  "id": 1421,
+                  "name": "tokenId",
+                  "nodeType": "VariableDeclaration",
+                  "scope": 1447,
+                  "src": "36242:15:1",
+                  "stateVariable": false,
+                  "storageLocation": "default",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_uint256",
+                    "typeString": "uint256"
+                  },
+                  "typeName": {
+                    "id": 1420,
+                    "name": "uint256",
+                    "nodeType": "ElementaryTypeName",
+                    "src": "36242:7:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_uint256",
+                      "typeString": "uint256"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                }
+              ],
+              "src": "36226:32:1"
+            },
+            "returnParameters": {
+              "id": 1423,
+              "nodeType": "ParameterList",
+              "parameters": [],
+              "src": "36268:0:1"
+            },
+            "scope": 1448,
+            "src": "36212:240:1",
+            "stateMutability": "nonpayable",
+            "superFunction": 811,
+            "visibility": "internal"
+          }
+        ],
+        "scope": 1469,
+        "src": "33817:2637:1"
+      },
+      {
+        "id": 1449,
+        "literals": [
+          "solidity",
+          "^",
+          "0.5",
+          ".0"
+        ],
+        "nodeType": "PragmaDirective",
+        "src": "36518:23:1"
+      },
+      {
+        "baseContracts": [
+          {
+            "arguments": null,
+            "baseName": {
+              "contractScope": null,
+              "id": 1450,
+              "name": "ERC721",
+              "nodeType": "UserDefinedTypeName",
+              "referencedDeclaration": 944,
+              "src": "36838:6:1",
+              "typeDescriptions": {
+                "typeIdentifier": "t_contract$_ERC721_$944",
+                "typeString": "contract ERC721"
+              }
+            },
+            "id": 1451,
+            "nodeType": "InheritanceSpecifier",
+            "src": "36838:6:1"
+          },
+          {
+            "arguments": null,
+            "baseName": {
+              "contractScope": null,
+              "id": 1452,
+              "name": "ERC721Enumerable",
+              "nodeType": "UserDefinedTypeName",
+              "referencedDeclaration": 1302,
+              "src": "36846:16:1",
+              "typeDescriptions": {
+                "typeIdentifier": "t_contract$_ERC721Enumerable_$1302",
+                "typeString": "contract ERC721Enumerable"
+              }
+            },
+            "id": 1453,
+            "nodeType": "InheritanceSpecifier",
+            "src": "36846:16:1"
+          },
+          {
+            "arguments": null,
+            "baseName": {
+              "contractScope": null,
+              "id": 1454,
+              "name": "ERC721Metadata",
+              "nodeType": "UserDefinedTypeName",
+              "referencedDeclaration": 1448,
+              "src": "36864:14:1",
+              "typeDescriptions": {
+                "typeIdentifier": "t_contract$_ERC721Metadata_$1448",
+                "typeString": "contract ERC721Metadata"
+              }
+            },
+            "id": 1455,
+            "nodeType": "InheritanceSpecifier",
+            "src": "36864:14:1"
+          }
+        ],
+        "contractDependencies": [
+          944,
+          969,
+          23,
+          124,
+          386,
+          1302,
+          1323,
+          1448
+        ],
+        "contractKind": "contract",
+        "documentation": "@title Full ERC721 Token\nThis implementation includes all the required and some optional functionality of the ERC721 standard\nMoreover, it includes approve all functionality using operator terminology\n@dev see https://eips.ethereum.org/EIPS/eip-721",
+        "fullyImplemented": true,
+        "id": 1468,
+        "linearizedBaseContracts": [
+          1468,
+          1448,
+          1323,
+          1302,
+          969,
+          944,
+          124,
+          386,
+          23
+        ],
+        "name": "ERC721Full",
+        "nodeType": "ContractDefinition",
+        "nodes": [
+          {
+            "body": {
+              "id": 1466,
+              "nodeType": "Block",
+              "src": "36976:64:1",
+              "statements": []
+            },
+            "documentation": null,
+            "id": 1467,
+            "implemented": true,
+            "kind": "constructor",
+            "modifiers": [
+              {
+                "arguments": [
+                  {
+                    "argumentTypes": null,
+                    "id": 1462,
+                    "name": "name",
+                    "nodeType": "Identifier",
+                    "overloadedDeclarations": [],
+                    "referencedDeclaration": 1457,
+                    "src": "36962:4:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_string_memory_ptr",
+                      "typeString": "string memory"
+                    }
+                  },
+                  {
+                    "argumentTypes": null,
+                    "id": 1463,
+                    "name": "symbol",
+                    "nodeType": "Identifier",
+                    "overloadedDeclarations": [],
+                    "referencedDeclaration": 1459,
+                    "src": "36968:6:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_string_memory_ptr",
+                      "typeString": "string memory"
+                    }
+                  }
+                ],
+                "id": 1464,
+                "modifierName": {
+                  "argumentTypes": null,
+                  "id": 1461,
+                  "name": "ERC721Metadata",
+                  "nodeType": "Identifier",
+                  "overloadedDeclarations": [],
+                  "referencedDeclaration": 1448,
+                  "src": "36947:14:1",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_type$_t_contract$_ERC721Metadata_$1448_$",
+                    "typeString": "type(contract ERC721Metadata)"
+                  }
+                },
+                "nodeType": "ModifierInvocation",
+                "src": "36947:28:1"
+              }
+            ],
+            "name": "",
+            "nodeType": "FunctionDefinition",
+            "parameters": {
+              "id": 1460,
+              "nodeType": "ParameterList",
+              "parameters": [
+                {
+                  "constant": false,
+                  "id": 1457,
+                  "name": "name",
+                  "nodeType": "VariableDeclaration",
+                  "scope": 1467,
+                  "src": "36898:18:1",
+                  "stateVariable": false,
+                  "storageLocation": "memory",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_string_memory_ptr",
+                    "typeString": "string"
+                  },
+                  "typeName": {
+                    "id": 1456,
+                    "name": "string",
+                    "nodeType": "ElementaryTypeName",
+                    "src": "36898:6:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_string_storage_ptr",
+                      "typeString": "string"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                },
+                {
+                  "constant": false,
+                  "id": 1459,
+                  "name": "symbol",
+                  "nodeType": "VariableDeclaration",
+                  "scope": 1467,
+                  "src": "36918:20:1",
+                  "stateVariable": false,
+                  "storageLocation": "memory",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_string_memory_ptr",
+                    "typeString": "string"
+                  },
+                  "typeName": {
+                    "id": 1458,
+                    "name": "string",
+                    "nodeType": "ElementaryTypeName",
+                    "src": "36918:6:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_string_storage_ptr",
+                      "typeString": "string"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                }
+              ],
+              "src": "36897:42:1"
+            },
+            "returnParameters": {
+              "id": 1465,
+              "nodeType": "ParameterList",
+              "parameters": [],
+              "src": "36976:0:1"
+            },
+            "scope": 1468,
+            "src": "36885:155:1",
+            "stateMutability": "nonpayable",
+            "superFunction": null,
+            "visibility": "public"
+          }
+        ],
+        "scope": 1469,
+        "src": "36815:227:1"
+      }
+    ],
+    "src": "61:36982:1"
+  },
+  "compiler": {
+    "name": "solc",
+    "version": "0.5.0+commit.1d4f565a.Emscripten.clang"
+  },
+  "networks": {},
+  "schemaVersion": "3.0.2",
+  "updatedAt": "2019-09-05T15:01:08.603Z",
+  "devdoc": {
+    "details": "see https://eips.ethereum.org/EIPS/eip-721",
+    "methods": {
+      "approve(address,uint256)": {
+        "details": "Approves another address to transfer the given token ID The zero address indicates there is no approved address. There can only be one approved address per token at a given time. Can only be called by the token owner or an approved operator.",
+        "params": {
+          "to": "address to be approved for the given token ID",
+          "tokenId": "uint256 ID of the token to be approved"
+        }
+      },
+      "balanceOf(address)": {
+        "details": "Gets the balance of the specified address.",
+        "params": {
+          "owner": "address to query the balance of"
+        },
+        "return": "uint256 representing the amount owned by the passed address"
+      },
+      "getApproved(uint256)": {
+        "details": "Gets the approved address for a token ID, or zero if no address set Reverts if the token ID does not exist.",
+        "params": {
+          "tokenId": "uint256 ID of the token to query the approval of"
+        },
+        "return": "address currently approved for the given token ID"
+      },
+      "isApprovedForAll(address,address)": {
+        "details": "Tells whether an operator is approved by a given owner.",
+        "params": {
+          "operator": "operator address which you want to query the approval of",
+          "owner": "owner address which you want to query the approval of"
+        },
+        "return": "bool whether the given operator is approved by the given owner"
+      },
+      "ownerOf(uint256)": {
+        "details": "Gets the owner of the specified token ID.",
+        "params": {
+          "tokenId": "uint256 ID of the token to query the owner of"
+        },
+        "return": "address currently marked as the owner of the given token ID"
+      },
+      "safeTransferFrom(address,address,uint256)": {
+        "details": "Safely transfers the ownership of a given token ID to another address If the target address is a contract, it must implement `onERC721Received`, which is called upon a safe transfer, and return the magic value `bytes4(keccak256(\"onERC721Received(address,address,uint256,bytes)\"))`; otherwise, the transfer is reverted. Requires the msg.sender to be the owner, approved, or operator",
+        "params": {
+          "from": "current owner of the token",
+          "to": "address to receive the ownership of the given token ID",
+          "tokenId": "uint256 ID of the token to be transferred"
+        }
+      },
+      "safeTransferFrom(address,address,uint256,bytes)": {
+        "details": "Safely transfers the ownership of a given token ID to another address If the target address is a contract, it must implement `onERC721Received`, which is called upon a safe transfer, and return the magic value `bytes4(keccak256(\"onERC721Received(address,address,uint256,bytes)\"))`; otherwise, the transfer is reverted. Requires the msg.sender to be the owner, approved, or operator",
+        "params": {
+          "_data": "bytes data to send along with a safe transfer check",
+          "from": "current owner of the token",
+          "to": "address to receive the ownership of the given token ID",
+          "tokenId": "uint256 ID of the token to be transferred"
+        }
+      },
+      "setApprovalForAll(address,bool)": {
+        "details": "Sets or unsets the approval of a given operator An operator is allowed to transfer all tokens of the sender on their behalf.",
+        "params": {
+          "approved": "representing the status of the approval to be set",
+          "to": "operator address to set the approval"
+        }
+      },
+      "supportsInterface(bytes4)": {
+        "details": "See `IERC165.supportsInterface`.     * Time complexity O(1), guaranteed to always use less than 30 000 gas."
+      },
+      "transferFrom(address,address,uint256)": {
+        "details": "Transfers the ownership of a given token ID to another address. Usage of this method is discouraged, use `safeTransferFrom` whenever possible. Requires the msg.sender to be the owner, approved, or operator.",
+        "params": {
+          "from": "current owner of the token",
+          "to": "address to receive the ownership of the given token ID",
+          "tokenId": "uint256 ID of the token to be transferred"
+        }
+      }
+    },
+    "title": "ERC721 Non-Fungible Token Standard basic implementation"
+  },
+  "userdoc": {
+    "methods": {}
+  }
+}
\ No newline at end of file
diff --git a/src/abis/ERC721Enumerable.json b/src/abis/ERC721Enumerable.json
new file mode 100644
index 0000000..ead537f
--- /dev/null
+++ b/src/abis/ERC721Enumerable.json
@@ -0,0 +1,37877 @@
+{
+  "contractName": "ERC721Enumerable",
+  "abi": [
+    {
+      "constant": true,
+      "inputs": [
+        {
+          "name": "interfaceId",
+          "type": "bytes4"
+        }
+      ],
+      "name": "supportsInterface",
+      "outputs": [
+        {
+          "name": "",
+          "type": "bool"
+        }
+      ],
+      "payable": false,
+      "stateMutability": "view",
+      "type": "function"
+    },
+    {
+      "constant": true,
+      "inputs": [
+        {
+          "name": "tokenId",
+          "type": "uint256"
+        }
+      ],
+      "name": "getApproved",
+      "outputs": [
+        {
+          "name": "",
+          "type": "address"
+        }
+      ],
+      "payable": false,
+      "stateMutability": "view",
+      "type": "function"
+    },
+    {
+      "constant": false,
+      "inputs": [
+        {
+          "name": "to",
+          "type": "address"
+        },
+        {
+          "name": "tokenId",
+          "type": "uint256"
+        }
+      ],
+      "name": "approve",
+      "outputs": [],
+      "payable": false,
+      "stateMutability": "nonpayable",
+      "type": "function"
+    },
+    {
+      "constant": false,
+      "inputs": [
+        {
+          "name": "from",
+          "type": "address"
+        },
+        {
+          "name": "to",
+          "type": "address"
+        },
+        {
+          "name": "tokenId",
+          "type": "uint256"
+        }
+      ],
+      "name": "transferFrom",
+      "outputs": [],
+      "payable": false,
+      "stateMutability": "nonpayable",
+      "type": "function"
+    },
+    {
+      "constant": false,
+      "inputs": [
+        {
+          "name": "from",
+          "type": "address"
+        },
+        {
+          "name": "to",
+          "type": "address"
+        },
+        {
+          "name": "tokenId",
+          "type": "uint256"
+        }
+      ],
+      "name": "safeTransferFrom",
+      "outputs": [],
+      "payable": false,
+      "stateMutability": "nonpayable",
+      "type": "function"
+    },
+    {
+      "constant": true,
+      "inputs": [
+        {
+          "name": "tokenId",
+          "type": "uint256"
+        }
+      ],
+      "name": "ownerOf",
+      "outputs": [
+        {
+          "name": "",
+          "type": "address"
+        }
+      ],
+      "payable": false,
+      "stateMutability": "view",
+      "type": "function"
+    },
+    {
+      "constant": true,
+      "inputs": [
+        {
+          "name": "owner",
+          "type": "address"
+        }
+      ],
+      "name": "balanceOf",
+      "outputs": [
+        {
+          "name": "",
+          "type": "uint256"
+        }
+      ],
+      "payable": false,
+      "stateMutability": "view",
+      "type": "function"
+    },
+    {
+      "constant": false,
+      "inputs": [
+        {
+          "name": "to",
+          "type": "address"
+        },
+        {
+          "name": "approved",
+          "type": "bool"
+        }
+      ],
+      "name": "setApprovalForAll",
+      "outputs": [],
+      "payable": false,
+      "stateMutability": "nonpayable",
+      "type": "function"
+    },
+    {
+      "constant": false,
+      "inputs": [
+        {
+          "name": "from",
+          "type": "address"
+        },
+        {
+          "name": "to",
+          "type": "address"
+        },
+        {
+          "name": "tokenId",
+          "type": "uint256"
+        },
+        {
+          "name": "_data",
+          "type": "bytes"
+        }
+      ],
+      "name": "safeTransferFrom",
+      "outputs": [],
+      "payable": false,
+      "stateMutability": "nonpayable",
+      "type": "function"
+    },
+    {
+      "constant": true,
+      "inputs": [
+        {
+          "name": "owner",
+          "type": "address"
+        },
+        {
+          "name": "operator",
+          "type": "address"
+        }
+      ],
+      "name": "isApprovedForAll",
+      "outputs": [
+        {
+          "name": "",
+          "type": "bool"
+        }
+      ],
+      "payable": false,
+      "stateMutability": "view",
+      "type": "function"
+    },
+    {
+      "inputs": [],
+      "payable": false,
+      "stateMutability": "nonpayable",
+      "type": "constructor"
+    },
+    {
+      "anonymous": false,
+      "inputs": [
+        {
+          "indexed": true,
+          "name": "from",
+          "type": "address"
+        },
+        {
+          "indexed": true,
+          "name": "to",
+          "type": "address"
+        },
+        {
+          "indexed": true,
+          "name": "tokenId",
+          "type": "uint256"
+        }
+      ],
+      "name": "Transfer",
+      "type": "event"
+    },
+    {
+      "anonymous": false,
+      "inputs": [
+        {
+          "indexed": true,
+          "name": "owner",
+          "type": "address"
+        },
+        {
+          "indexed": true,
+          "name": "approved",
+          "type": "address"
+        },
+        {
+          "indexed": true,
+          "name": "tokenId",
+          "type": "uint256"
+        }
+      ],
+      "name": "Approval",
+      "type": "event"
+    },
+    {
+      "anonymous": false,
+      "inputs": [
+        {
+          "indexed": true,
+          "name": "owner",
+          "type": "address"
+        },
+        {
+          "indexed": true,
+          "name": "operator",
+          "type": "address"
+        },
+        {
+          "indexed": false,
+          "name": "approved",
+          "type": "bool"
+        }
+      ],
+      "name": "ApprovalForAll",
+      "type": "event"
+    },
+    {
+      "constant": true,
+      "inputs": [
+        {
+          "name": "owner",
+          "type": "address"
+        },
+        {
+          "name": "index",
+          "type": "uint256"
+        }
+      ],
+      "name": "tokenOfOwnerByIndex",
+      "outputs": [
+        {
+          "name": "",
+          "type": "uint256"
+        }
+      ],
+      "payable": false,
+      "stateMutability": "view",
+      "type": "function"
+    },
+    {
+      "constant": true,
+      "inputs": [],
+      "name": "totalSupply",
+      "outputs": [
+        {
+          "name": "",
+          "type": "uint256"
+        }
+      ],
+      "payable": false,
+      "stateMutability": "view",
+      "type": "function"
+    },
+    {
+      "constant": true,
+      "inputs": [
+        {
+          "name": "index",
+          "type": "uint256"
+        }
+      ],
+      "name": "tokenByIndex",
+      "outputs": [
+        {
+          "name": "",
+          "type": "uint256"
+        }
+      ],
+      "payable": false,
+      "stateMutability": "view",
+      "type": "function"
+    }
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+  "source": "\n// File: @openzeppelin/contracts/introspection/IERC165.sol\n\npragma solidity ^0.5.0;\n\n/**\n * @dev Interface of the ERC165 standard, as defined in the\n * [EIP](https://eips.ethereum.org/EIPS/eip-165).\n *\n * Implementers can declare support of contract interfaces, which can then be\n * queried by others (`ERC165Checker`).\n *\n * For an implementation, see `ERC165`.\n */\ninterface IERC165 {\n    /**\n     * @dev Returns true if this contract implements the interface defined by\n     * `interfaceId`. See the corresponding\n     * [EIP section](https://eips.ethereum.org/EIPS/eip-165#how-interfaces-are-identified)\n     * to learn more about how these ids are created.\n     *\n     * This function call must use less than 30 000 gas.\n     */\n    function supportsInterface(bytes4 interfaceId) external view returns (bool);\n}\n\n// File: @openzeppelin/contracts/token/ERC721/IERC721.sol\n\npragma solidity ^0.5.0;\n\n\n/**\n * @dev Required interface of an ERC721 compliant contract.\n */\ncontract IERC721 is IERC165 {\n    event Transfer(address indexed from, address indexed to, uint256 indexed tokenId);\n    event Approval(address indexed owner, address indexed approved, uint256 indexed tokenId);\n    event ApprovalForAll(address indexed owner, address indexed operator, bool approved);\n\n    /**\n     * @dev Returns the number of NFTs in `owner`'s account.\n     */\n    function balanceOf(address owner) public view returns (uint256 balance);\n\n    /**\n     * @dev Returns the owner of the NFT specified by `tokenId`.\n     */\n    function ownerOf(uint256 tokenId) public view returns (address owner);\n\n    /**\n     * @dev Transfers a specific NFT (`tokenId`) from one account (`from`) to\n     * another (`to`).\n     *\n     * \n     *\n     * Requirements:\n     * - `from`, `to` cannot be zero.\n     * - `tokenId` must be owned by `from`.\n     * - If the caller is not `from`, it must be have been allowed to move this\n     * NFT by either `approve` or `setApproveForAll`.\n     */\n    function safeTransferFrom(address from, address to, uint256 tokenId) public;\n    /**\n     * @dev Transfers a specific NFT (`tokenId`) from one account (`from`) to\n     * another (`to`).\n     *\n     * Requirements:\n     * - If the caller is not `from`, it must be approved to move this NFT by\n     * either `approve` or `setApproveForAll`.\n     */\n    function transferFrom(address from, address to, uint256 tokenId) public;\n    function approve(address to, uint256 tokenId) public;\n    function getApproved(uint256 tokenId) public view returns (address operator);\n\n    function setApprovalForAll(address operator, bool _approved) public;\n    function isApprovedForAll(address owner, address operator) public view returns (bool);\n\n\n    function safeTransferFrom(address from, address to, uint256 tokenId, bytes memory data) public;\n}\n\n// File: @openzeppelin/contracts/token/ERC721/IERC721Receiver.sol\n\npragma solidity ^0.5.0;\n\n/**\n * @title ERC721 token receiver interface\n * @dev Interface for any contract that wants to support safeTransfers\n * from ERC721 asset contracts.\n */\ncontract IERC721Receiver {\n    /**\n     * @notice Handle the receipt of an NFT\n     * @dev The ERC721 smart contract calls this function on the recipient\n     * after a `safeTransfer`. This function MUST return the function selector,\n     * otherwise the caller will revert the transaction. The selector to be\n     * returned can be obtained as `this.onERC721Received.selector`. This\n     * function MAY throw to revert and reject the transfer.\n     * Note: the ERC721 contract address is always the message sender.\n     * @param operator The address which called `safeTransferFrom` function\n     * @param from The address which previously owned the token\n     * @param tokenId The NFT identifier which is being transferred\n     * @param data Additional data with no specified format\n     * @return bytes4 `bytes4(keccak256(\"onERC721Received(address,address,uint256,bytes)\"))`\n     */\n    function onERC721Received(address operator, address from, uint256 tokenId, bytes memory data)\n    public returns (bytes4);\n}\n\n// File: @openzeppelin/contracts/math/SafeMath.sol\n\npragma solidity ^0.5.0;\n\n/**\n * @dev Wrappers over Solidity's arithmetic operations with added overflow\n * checks.\n *\n * Arithmetic operations in Solidity wrap on overflow. This can easily result\n * in bugs, because programmers usually assume that an overflow raises an\n * error, which is the standard behavior in high level programming languages.\n * `SafeMath` restores this intuition by reverting the transaction when an\n * operation overflows.\n *\n * Using this library instead of the unchecked operations eliminates an entire\n * class of bugs, so it's recommended to use it always.\n */\nlibrary SafeMath {\n    /**\n     * @dev Returns the addition of two unsigned integers, reverting on\n     * overflow.\n     *\n     * Counterpart to Solidity's `+` operator.\n     *\n     * Requirements:\n     * - Addition cannot overflow.\n     */\n    function add(uint256 a, uint256 b) internal pure returns (uint256) {\n        uint256 c = a + b;\n        require(c >= a, \"SafeMath: addition overflow\");\n\n        return c;\n    }\n\n    /**\n     * @dev Returns the subtraction of two unsigned integers, reverting on\n     * overflow (when the result is negative).\n     *\n     * Counterpart to Solidity's `-` operator.\n     *\n     * Requirements:\n     * - Subtraction cannot overflow.\n     */\n    function sub(uint256 a, uint256 b) internal pure returns (uint256) {\n        require(b <= a, \"SafeMath: subtraction overflow\");\n        uint256 c = a - b;\n\n        return c;\n    }\n\n    /**\n     * @dev Returns the multiplication of two unsigned integers, reverting on\n     * overflow.\n     *\n     * Counterpart to Solidity's `*` operator.\n     *\n     * Requirements:\n     * - Multiplication cannot overflow.\n     */\n    function mul(uint256 a, uint256 b) internal pure returns (uint256) {\n        // Gas optimization: this is cheaper than requiring 'a' not being zero, but the\n        // benefit is lost if 'b' is also tested.\n        // See: https://github.com/OpenZeppelin/openzeppelin-contracts/pull/522\n        if (a == 0) {\n            return 0;\n        }\n\n        uint256 c = a * b;\n        require(c / a == b, \"SafeMath: multiplication overflow\");\n\n        return c;\n    }\n\n    /**\n     * @dev Returns the integer division of two unsigned integers. Reverts on\n     * division by zero. The result is rounded towards zero.\n     *\n     * Counterpart to Solidity's `/` operator. Note: this function uses a\n     * `revert` opcode (which leaves remaining gas untouched) while Solidity\n     * uses an invalid opcode to revert (consuming all remaining gas).\n     *\n     * Requirements:\n     * - The divisor cannot be zero.\n     */\n    function div(uint256 a, uint256 b) internal pure returns (uint256) {\n        // Solidity only automatically asserts when dividing by 0\n        require(b > 0, \"SafeMath: division by zero\");\n        uint256 c = a / b;\n        // assert(a == b * c + a % b); // There is no case in which this doesn't hold\n\n        return c;\n    }\n\n    /**\n     * @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo),\n     * Reverts when dividing by zero.\n     *\n     * Counterpart to Solidity's `%` operator. This function uses a `revert`\n     * opcode (which leaves remaining gas untouched) while Solidity uses an\n     * invalid opcode to revert (consuming all remaining gas).\n     *\n     * Requirements:\n     * - The divisor cannot be zero.\n     */\n    function mod(uint256 a, uint256 b) internal pure returns (uint256) {\n        require(b != 0, \"SafeMath: modulo by zero\");\n        return a % b;\n    }\n}\n\n// File: @openzeppelin/contracts/utils/Address.sol\n\npragma solidity ^0.5.0;\n\n/**\n * @dev Collection of functions related to the address type,\n */\nlibrary Address {\n    /**\n     * @dev Returns true if `account` is a contract.\n     *\n     * This test is non-exhaustive, and there may be false-negatives: during the\n     * execution of a contract's constructor, its address will be reported as\n     * not containing a contract.\n     *\n     * > It is unsafe to assume that an address for which this function returns\n     * false is an externally-owned account (EOA) and not a contract.\n     */\n    function isContract(address account) internal view returns (bool) {\n        // This method relies in extcodesize, which returns 0 for contracts in\n        // construction, since the code is only stored at the end of the\n        // constructor execution.\n\n        uint256 size;\n        // solhint-disable-next-line no-inline-assembly\n        assembly { size := extcodesize(account) }\n        return size > 0;\n    }\n}\n\n// File: @openzeppelin/contracts/drafts/Counters.sol\n\npragma solidity ^0.5.0;\n\n\n/**\n * @title Counters\n * @author Matt Condon (@shrugs)\n * @dev Provides counters that can only be incremented or decremented by one. This can be used e.g. to track the number\n * of elements in a mapping, issuing ERC721 ids, or counting request ids.\n *\n * Include with `using Counters for Counters.Counter;`\n * Since it is not possible to overflow a 256 bit integer with increments of one, `increment` can skip the SafeMath\n * overflow check, thereby saving gas. This does assume however correct usage, in that the underlying `_value` is never\n * directly accessed.\n */\nlibrary Counters {\n    using SafeMath for uint256;\n\n    struct Counter {\n        // This variable should never be directly accessed by users of the library: interactions must be restricted to\n        // the library's function. As of Solidity v0.5.2, this cannot be enforced, though there is a proposal to add\n        // this feature: see https://github.com/ethereum/solidity/issues/4637\n        uint256 _value; // default: 0\n    }\n\n    function current(Counter storage counter) internal view returns (uint256) {\n        return counter._value;\n    }\n\n    function increment(Counter storage counter) internal {\n        counter._value += 1;\n    }\n\n    function decrement(Counter storage counter) internal {\n        counter._value = counter._value.sub(1);\n    }\n}\n\n// File: @openzeppelin/contracts/introspection/ERC165.sol\n\npragma solidity ^0.5.0;\n\n\n/**\n * @dev Implementation of the `IERC165` interface.\n *\n * Contracts may inherit from this and call `_registerInterface` to declare\n * their support of an interface.\n */\ncontract ERC165 is IERC165 {\n    /*\n     * bytes4(keccak256('supportsInterface(bytes4)')) == 0x01ffc9a7\n     */\n    bytes4 private constant _INTERFACE_ID_ERC165 = 0x01ffc9a7;\n\n    /**\n     * @dev Mapping of interface ids to whether or not it's supported.\n     */\n    mapping(bytes4 => bool) private _supportedInterfaces;\n\n    constructor () internal {\n        // Derived contracts need only register support for their own interfaces,\n        // we register support for ERC165 itself here\n        _registerInterface(_INTERFACE_ID_ERC165);\n    }\n\n    /**\n     * @dev See `IERC165.supportsInterface`.\n     *\n     * Time complexity O(1), guaranteed to always use less than 30 000 gas.\n     */\n    function supportsInterface(bytes4 interfaceId) external view returns (bool) {\n        return _supportedInterfaces[interfaceId];\n    }\n\n    /**\n     * @dev Registers the contract as an implementer of the interface defined by\n     * `interfaceId`. Support of the actual ERC165 interface is automatic and\n     * registering its interface id is not required.\n     *\n     * See `IERC165.supportsInterface`.\n     *\n     * Requirements:\n     *\n     * - `interfaceId` cannot be the ERC165 invalid interface (`0xffffffff`).\n     */\n    function _registerInterface(bytes4 interfaceId) internal {\n        require(interfaceId != 0xffffffff, \"ERC165: invalid interface id\");\n        _supportedInterfaces[interfaceId] = true;\n    }\n}\n\n// File: @openzeppelin/contracts/token/ERC721/ERC721.sol\n\npragma solidity ^0.5.0;\n\n\n\n\n\n\n\n/**\n * @title ERC721 Non-Fungible Token Standard basic implementation\n * @dev see https://eips.ethereum.org/EIPS/eip-721\n */\ncontract ERC721 is ERC165, IERC721 {\n    using SafeMath for uint256;\n    using Address for address;\n    using Counters for Counters.Counter;\n\n    // Equals to `bytes4(keccak256(\"onERC721Received(address,address,uint256,bytes)\"))`\n    // which can be also obtained as `IERC721Receiver(0).onERC721Received.selector`\n    bytes4 private constant _ERC721_RECEIVED = 0x150b7a02;\n\n    // Mapping from token ID to owner\n    mapping (uint256 => address) private _tokenOwner;\n\n    // Mapping from token ID to approved address\n    mapping (uint256 => address) private _tokenApprovals;\n\n    // Mapping from owner to number of owned token\n    mapping (address => Counters.Counter) private _ownedTokensCount;\n\n    // Mapping from owner to operator approvals\n    mapping (address => mapping (address => bool)) private _operatorApprovals;\n\n    /*\n     *     bytes4(keccak256('balanceOf(address)')) == 0x70a08231\n     *     bytes4(keccak256('ownerOf(uint256)')) == 0x6352211e\n     *     bytes4(keccak256('approve(address,uint256)')) == 0x095ea7b3\n     *     bytes4(keccak256('getApproved(uint256)')) == 0x081812fc\n     *     bytes4(keccak256('setApprovalForAll(address,bool)')) == 0xa22cb465\n     *     bytes4(keccak256('isApprovedForAll(address,address)')) == 0xe985e9c\n     *     bytes4(keccak256('transferFrom(address,address,uint256)')) == 0x23b872dd\n     *     bytes4(keccak256('safeTransferFrom(address,address,uint256)')) == 0x42842e0e\n     *     bytes4(keccak256('safeTransferFrom(address,address,uint256,bytes)')) == 0xb88d4fde\n     *\n     *     => 0x70a08231 ^ 0x6352211e ^ 0x095ea7b3 ^ 0x081812fc ^\n     *        0xa22cb465 ^ 0xe985e9c ^ 0x23b872dd ^ 0x42842e0e ^ 0xb88d4fde == 0x80ac58cd\n     */\n    bytes4 private constant _INTERFACE_ID_ERC721 = 0x80ac58cd;\n\n    constructor () public {\n        // register the supported interfaces to conform to ERC721 via ERC165\n        _registerInterface(_INTERFACE_ID_ERC721);\n    }\n\n    /**\n     * @dev Gets the balance of the specified address.\n     * @param owner address to query the balance of\n     * @return uint256 representing the amount owned by the passed address\n     */\n    function balanceOf(address owner) public view returns (uint256) {\n        require(owner != address(0), \"ERC721: balance query for the zero address\");\n\n        return _ownedTokensCount[owner].current();\n    }\n\n    /**\n     * @dev Gets the owner of the specified token ID.\n     * @param tokenId uint256 ID of the token to query the owner of\n     * @return address currently marked as the owner of the given token ID\n     */\n    function ownerOf(uint256 tokenId) public view returns (address) {\n        address owner = _tokenOwner[tokenId];\n        require(owner != address(0), \"ERC721: owner query for nonexistent token\");\n\n        return owner;\n    }\n\n    /**\n     * @dev Approves another address to transfer the given token ID\n     * The zero address indicates there is no approved address.\n     * There can only be one approved address per token at a given time.\n     * Can only be called by the token owner or an approved operator.\n     * @param to address to be approved for the given token ID\n     * @param tokenId uint256 ID of the token to be approved\n     */\n    function approve(address to, uint256 tokenId) public {\n        address owner = ownerOf(tokenId);\n        require(to != owner, \"ERC721: approval to current owner\");\n\n        require(msg.sender == owner || isApprovedForAll(owner, msg.sender),\n            \"ERC721: approve caller is not owner nor approved for all\"\n        );\n\n        _tokenApprovals[tokenId] = to;\n        emit Approval(owner, to, tokenId);\n    }\n\n    /**\n     * @dev Gets the approved address for a token ID, or zero if no address set\n     * Reverts if the token ID does not exist.\n     * @param tokenId uint256 ID of the token to query the approval of\n     * @return address currently approved for the given token ID\n     */\n    function getApproved(uint256 tokenId) public view returns (address) {\n        require(_exists(tokenId), \"ERC721: approved query for nonexistent token\");\n\n        return _tokenApprovals[tokenId];\n    }\n\n    /**\n     * @dev Sets or unsets the approval of a given operator\n     * An operator is allowed to transfer all tokens of the sender on their behalf.\n     * @param to operator address to set the approval\n     * @param approved representing the status of the approval to be set\n     */\n    function setApprovalForAll(address to, bool approved) public {\n        require(to != msg.sender, \"ERC721: approve to caller\");\n\n        _operatorApprovals[msg.sender][to] = approved;\n        emit ApprovalForAll(msg.sender, to, approved);\n    }\n\n    /**\n     * @dev Tells whether an operator is approved by a given owner.\n     * @param owner owner address which you want to query the approval of\n     * @param operator operator address which you want to query the approval of\n     * @return bool whether the given operator is approved by the given owner\n     */\n    function isApprovedForAll(address owner, address operator) public view returns (bool) {\n        return _operatorApprovals[owner][operator];\n    }\n\n    /**\n     * @dev Transfers the ownership of a given token ID to another address.\n     * Usage of this method is discouraged, use `safeTransferFrom` whenever possible.\n     * Requires the msg.sender to be the owner, approved, or operator.\n     * @param from current owner of the token\n     * @param to address to receive the ownership of the given token ID\n     * @param tokenId uint256 ID of the token to be transferred\n     */\n    function transferFrom(address from, address to, uint256 tokenId) public {\n        //solhint-disable-next-line max-line-length\n        require(_isApprovedOrOwner(msg.sender, tokenId), \"ERC721: transfer caller is not owner nor approved\");\n\n        _transferFrom(from, to, tokenId);\n    }\n\n    /**\n     * @dev Safely transfers the ownership of a given token ID to another address\n     * If the target address is a contract, it must implement `onERC721Received`,\n     * which is called upon a safe transfer, and return the magic value\n     * `bytes4(keccak256(\"onERC721Received(address,address,uint256,bytes)\"))`; otherwise,\n     * the transfer is reverted.\n     * Requires the msg.sender to be the owner, approved, or operator\n     * @param from current owner of the token\n     * @param to address to receive the ownership of the given token ID\n     * @param tokenId uint256 ID of the token to be transferred\n     */\n    function safeTransferFrom(address from, address to, uint256 tokenId) public {\n        safeTransferFrom(from, to, tokenId, \"\");\n    }\n\n    /**\n     * @dev Safely transfers the ownership of a given token ID to another address\n     * If the target address is a contract, it must implement `onERC721Received`,\n     * which is called upon a safe transfer, and return the magic value\n     * `bytes4(keccak256(\"onERC721Received(address,address,uint256,bytes)\"))`; otherwise,\n     * the transfer is reverted.\n     * Requires the msg.sender to be the owner, approved, or operator\n     * @param from current owner of the token\n     * @param to address to receive the ownership of the given token ID\n     * @param tokenId uint256 ID of the token to be transferred\n     * @param _data bytes data to send along with a safe transfer check\n     */\n    function safeTransferFrom(address from, address to, uint256 tokenId, bytes memory _data) public {\n        transferFrom(from, to, tokenId);\n        require(_checkOnERC721Received(from, to, tokenId, _data), \"ERC721: transfer to non ERC721Receiver implementer\");\n    }\n\n    /**\n     * @dev Returns whether the specified token exists.\n     * @param tokenId uint256 ID of the token to query the existence of\n     * @return bool whether the token exists\n     */\n    function _exists(uint256 tokenId) internal view returns (bool) {\n        address owner = _tokenOwner[tokenId];\n        return owner != address(0);\n    }\n\n    /**\n     * @dev Returns whether the given spender can transfer a given token ID.\n     * @param spender address of the spender to query\n     * @param tokenId uint256 ID of the token to be transferred\n     * @return bool whether the msg.sender is approved for the given token ID,\n     * is an operator of the owner, or is the owner of the token\n     */\n    function _isApprovedOrOwner(address spender, uint256 tokenId) internal view returns (bool) {\n        require(_exists(tokenId), \"ERC721: operator query for nonexistent token\");\n        address owner = ownerOf(tokenId);\n        return (spender == owner || getApproved(tokenId) == spender || isApprovedForAll(owner, spender));\n    }\n\n    /**\n     * @dev Internal function to mint a new token.\n     * Reverts if the given token ID already exists.\n     * @param to The address that will own the minted token\n     * @param tokenId uint256 ID of the token to be minted\n     */\n    function _mint(address to, uint256 tokenId) internal {\n        require(to != address(0), \"ERC721: mint to the zero address\");\n        require(!_exists(tokenId), \"ERC721: token already minted\");\n\n        _tokenOwner[tokenId] = to;\n        _ownedTokensCount[to].increment();\n\n        emit Transfer(address(0), to, tokenId);\n    }\n\n    /**\n     * @dev Internal function to burn a specific token.\n     * Reverts if the token does not exist.\n     * Deprecated, use _burn(uint256) instead.\n     * @param owner owner of the token to burn\n     * @param tokenId uint256 ID of the token being burned\n     */\n    function _burn(address owner, uint256 tokenId) internal {\n        require(ownerOf(tokenId) == owner, \"ERC721: burn of token that is not own\");\n\n        _clearApproval(tokenId);\n\n        _ownedTokensCount[owner].decrement();\n        _tokenOwner[tokenId] = address(0);\n\n        emit Transfer(owner, address(0), tokenId);\n    }\n\n    /**\n     * @dev Internal function to burn a specific token.\n     * Reverts if the token does not exist.\n     * @param tokenId uint256 ID of the token being burned\n     */\n    function _burn(uint256 tokenId) internal {\n        _burn(ownerOf(tokenId), tokenId);\n    }\n\n    /**\n     * @dev Internal function to transfer ownership of a given token ID to another address.\n     * As opposed to transferFrom, this imposes no restrictions on msg.sender.\n     * @param from current owner of the token\n     * @param to address to receive the ownership of the given token ID\n     * @param tokenId uint256 ID of the token to be transferred\n     */\n    function _transferFrom(address from, address to, uint256 tokenId) internal {\n        require(ownerOf(tokenId) == from, \"ERC721: transfer of token that is not own\");\n        require(to != address(0), \"ERC721: transfer to the zero address\");\n\n        _clearApproval(tokenId);\n\n        _ownedTokensCount[from].decrement();\n        _ownedTokensCount[to].increment();\n\n        _tokenOwner[tokenId] = to;\n\n        emit Transfer(from, to, tokenId);\n    }\n\n    /**\n     * @dev Internal function to invoke `onERC721Received` on a target address.\n     * The call is not executed if the target address is not a contract.\n     *\n     * This function is deprecated.\n     * @param from address representing the previous owner of the given token ID\n     * @param to target address that will receive the tokens\n     * @param tokenId uint256 ID of the token to be transferred\n     * @param _data bytes optional data to send along with the call\n     * @return bool whether the call correctly returned the expected magic value\n     */\n    function _checkOnERC721Received(address from, address to, uint256 tokenId, bytes memory _data)\n        internal returns (bool)\n    {\n        if (!to.isContract()) {\n            return true;\n        }\n\n        bytes4 retval = IERC721Receiver(to).onERC721Received(msg.sender, from, tokenId, _data);\n        return (retval == _ERC721_RECEIVED);\n    }\n\n    /**\n     * @dev Private function to clear current approval of a given token ID.\n     * @param tokenId uint256 ID of the token to be transferred\n     */\n    function _clearApproval(uint256 tokenId) private {\n        if (_tokenApprovals[tokenId] != address(0)) {\n            _tokenApprovals[tokenId] = address(0);\n        }\n    }\n}\n\n// File: @openzeppelin/contracts/token/ERC721/IERC721Enumerable.sol\n\npragma solidity ^0.5.0;\n\n\n/**\n * @title ERC-721 Non-Fungible Token Standard, optional enumeration extension\n * @dev See https://eips.ethereum.org/EIPS/eip-721\n */\ncontract IERC721Enumerable is IERC721 {\n    function totalSupply() public view returns (uint256);\n    function tokenOfOwnerByIndex(address owner, uint256 index) public view returns (uint256 tokenId);\n\n    function tokenByIndex(uint256 index) public view returns (uint256);\n}\n\n// File: @openzeppelin/contracts/token/ERC721/ERC721Enumerable.sol\n\npragma solidity ^0.5.0;\n\n\n\n\n/**\n * @title ERC-721 Non-Fungible Token with optional enumeration extension logic\n * @dev See https://eips.ethereum.org/EIPS/eip-721\n */\ncontract ERC721Enumerable is ERC165, ERC721, IERC721Enumerable {\n    // Mapping from owner to list of owned token IDs\n    mapping(address => uint256[]) private _ownedTokens;\n\n    // Mapping from token ID to index of the owner tokens list\n    mapping(uint256 => uint256) private _ownedTokensIndex;\n\n    // Array with all token ids, used for enumeration\n    uint256[] private _allTokens;\n\n    // Mapping from token id to position in the allTokens array\n    mapping(uint256 => uint256) private _allTokensIndex;\n\n    /*\n     *     bytes4(keccak256('totalSupply()')) == 0x18160ddd\n     *     bytes4(keccak256('tokenOfOwnerByIndex(address,uint256)')) == 0x2f745c59\n     *     bytes4(keccak256('tokenByIndex(uint256)')) == 0x4f6ccce7\n     *\n     *     => 0x18160ddd ^ 0x2f745c59 ^ 0x4f6ccce7 == 0x780e9d63\n     */\n    bytes4 private constant _INTERFACE_ID_ERC721_ENUMERABLE = 0x780e9d63;\n\n    /**\n     * @dev Constructor function.\n     */\n    constructor () public {\n        // register the supported interface to conform to ERC721Enumerable via ERC165\n        _registerInterface(_INTERFACE_ID_ERC721_ENUMERABLE);\n    }\n\n    /**\n     * @dev Gets the token ID at a given index of the tokens list of the requested owner.\n     * @param owner address owning the tokens list to be accessed\n     * @param index uint256 representing the index to be accessed of the requested tokens list\n     * @return uint256 token ID at the given index of the tokens list owned by the requested address\n     */\n    function tokenOfOwnerByIndex(address owner, uint256 index) public view returns (uint256) {\n        require(index < balanceOf(owner), \"ERC721Enumerable: owner index out of bounds\");\n        return _ownedTokens[owner][index];\n    }\n\n    /**\n     * @dev Gets the total amount of tokens stored by the contract.\n     * @return uint256 representing the total amount of tokens\n     */\n    function totalSupply() public view returns (uint256) {\n        return _allTokens.length;\n    }\n\n    /**\n     * @dev Gets the token ID at a given index of all the tokens in this contract\n     * Reverts if the index is greater or equal to the total number of tokens.\n     * @param index uint256 representing the index to be accessed of the tokens list\n     * @return uint256 token ID at the given index of the tokens list\n     */\n    function tokenByIndex(uint256 index) public view returns (uint256) {\n        require(index < totalSupply(), \"ERC721Enumerable: global index out of bounds\");\n        return _allTokens[index];\n    }\n\n    /**\n     * @dev Internal function to transfer ownership of a given token ID to another address.\n     * As opposed to transferFrom, this imposes no restrictions on msg.sender.\n     * @param from current owner of the token\n     * @param to address to receive the ownership of the given token ID\n     * @param tokenId uint256 ID of the token to be transferred\n     */\n    function _transferFrom(address from, address to, uint256 tokenId) internal {\n        super._transferFrom(from, to, tokenId);\n\n        _removeTokenFromOwnerEnumeration(from, tokenId);\n\n        _addTokenToOwnerEnumeration(to, tokenId);\n    }\n\n    /**\n     * @dev Internal function to mint a new token.\n     * Reverts if the given token ID already exists.\n     * @param to address the beneficiary that will own the minted token\n     * @param tokenId uint256 ID of the token to be minted\n     */\n    function _mint(address to, uint256 tokenId) internal {\n        super._mint(to, tokenId);\n\n        _addTokenToOwnerEnumeration(to, tokenId);\n\n        _addTokenToAllTokensEnumeration(tokenId);\n    }\n\n    /**\n     * @dev Internal function to burn a specific token.\n     * Reverts if the token does not exist.\n     * Deprecated, use _burn(uint256) instead.\n     * @param owner owner of the token to burn\n     * @param tokenId uint256 ID of the token being burned\n     */\n    function _burn(address owner, uint256 tokenId) internal {\n        super._burn(owner, tokenId);\n\n        _removeTokenFromOwnerEnumeration(owner, tokenId);\n        // Since tokenId will be deleted, we can clear its slot in _ownedTokensIndex to trigger a gas refund\n        _ownedTokensIndex[tokenId] = 0;\n\n        _removeTokenFromAllTokensEnumeration(tokenId);\n    }\n\n    /**\n     * @dev Gets the list of token IDs of the requested owner.\n     * @param owner address owning the tokens\n     * @return uint256[] List of token IDs owned by the requested address\n     */\n    function _tokensOfOwner(address owner) internal view returns (uint256[] storage) {\n        return _ownedTokens[owner];\n    }\n\n    /**\n     * @dev Private function to add a token to this extension's ownership-tracking data structures.\n     * @param to address representing the new owner of the given token ID\n     * @param tokenId uint256 ID of the token to be added to the tokens list of the given address\n     */\n    function _addTokenToOwnerEnumeration(address to, uint256 tokenId) private {\n        _ownedTokensIndex[tokenId] = _ownedTokens[to].length;\n        _ownedTokens[to].push(tokenId);\n    }\n\n    /**\n     * @dev Private function to add a token to this extension's token tracking data structures.\n     * @param tokenId uint256 ID of the token to be added to the tokens list\n     */\n    function _addTokenToAllTokensEnumeration(uint256 tokenId) private {\n        _allTokensIndex[tokenId] = _allTokens.length;\n        _allTokens.push(tokenId);\n    }\n\n    /**\n     * @dev Private function to remove a token from this extension's ownership-tracking data structures. Note that\n     * while the token is not assigned a new owner, the _ownedTokensIndex mapping is _not_ updated: this allows for\n     * gas optimizations e.g. when performing a transfer operation (avoiding double writes).\n     * This has O(1) time complexity, but alters the order of the _ownedTokens array.\n     * @param from address representing the previous owner of the given token ID\n     * @param tokenId uint256 ID of the token to be removed from the tokens list of the given address\n     */\n    function _removeTokenFromOwnerEnumeration(address from, uint256 tokenId) private {\n        // To prevent a gap in from's tokens array, we store the last token in the index of the token to delete, and\n        // then delete the last slot (swap and pop).\n\n        uint256 lastTokenIndex = _ownedTokens[from].length.sub(1);\n        uint256 tokenIndex = _ownedTokensIndex[tokenId];\n\n        // When the token to delete is the last token, the swap operation is unnecessary\n        if (tokenIndex != lastTokenIndex) {\n            uint256 lastTokenId = _ownedTokens[from][lastTokenIndex];\n\n            _ownedTokens[from][tokenIndex] = lastTokenId; // Move the last token to the slot of the to-delete token\n            _ownedTokensIndex[lastTokenId] = tokenIndex; // Update the moved token's index\n        }\n\n        // This also deletes the contents at the last position of the array\n        _ownedTokens[from].length--;\n\n        // Note that _ownedTokensIndex[tokenId] hasn't been cleared: it still points to the old slot (now occupied by\n        // lastTokenId, or just over the end of the array if the token was the last one).\n    }\n\n    /**\n     * @dev Private function to remove a token from this extension's token tracking data structures.\n     * This has O(1) time complexity, but alters the order of the _allTokens array.\n     * @param tokenId uint256 ID of the token to be removed from the tokens list\n     */\n    function _removeTokenFromAllTokensEnumeration(uint256 tokenId) private {\n        // To prevent a gap in the tokens array, we store the last token in the index of the token to delete, and\n        // then delete the last slot (swap and pop).\n\n        uint256 lastTokenIndex = _allTokens.length.sub(1);\n        uint256 tokenIndex = _allTokensIndex[tokenId];\n\n        // When the token to delete is the last token, the swap operation is unnecessary. However, since this occurs so\n        // rarely (when the last minted token is burnt) that we still do the swap here to avoid the gas cost of adding\n        // an 'if' statement (like in _removeTokenFromOwnerEnumeration)\n        uint256 lastTokenId = _allTokens[lastTokenIndex];\n\n        _allTokens[tokenIndex] = lastTokenId; // Move the last token to the slot of the to-delete token\n        _allTokensIndex[lastTokenId] = tokenIndex; // Update the moved token's index\n\n        // This also deletes the contents at the last position of the array\n        _allTokens.length--;\n        _allTokensIndex[tokenId] = 0;\n    }\n}\n\n// File: @openzeppelin/contracts/token/ERC721/IERC721Metadata.sol\n\npragma solidity ^0.5.0;\n\n\n/**\n * @title ERC-721 Non-Fungible Token Standard, optional metadata extension\n * @dev See https://eips.ethereum.org/EIPS/eip-721\n */\ncontract IERC721Metadata is IERC721 {\n    function name() external view returns (string memory);\n    function symbol() external view returns (string memory);\n    function tokenURI(uint256 tokenId) external view returns (string memory);\n}\n\n// File: @openzeppelin/contracts/token/ERC721/ERC721Metadata.sol\n\npragma solidity ^0.5.0;\n\n\n\n\ncontract ERC721Metadata is ERC165, ERC721, IERC721Metadata {\n    // Token name\n    string private _name;\n\n    // Token symbol\n    string private _symbol;\n\n    // Optional mapping for token URIs\n    mapping(uint256 => string) private _tokenURIs;\n\n    /*\n     *     bytes4(keccak256('name()')) == 0x06fdde03\n     *     bytes4(keccak256('symbol()')) == 0x95d89b41\n     *     bytes4(keccak256('tokenURI(uint256)')) == 0xc87b56dd\n     *\n     *     => 0x06fdde03 ^ 0x95d89b41 ^ 0xc87b56dd == 0x5b5e139f\n     */\n    bytes4 private constant _INTERFACE_ID_ERC721_METADATA = 0x5b5e139f;\n\n    /**\n     * @dev Constructor function\n     */\n    constructor (string memory name, string memory symbol) public {\n        _name = name;\n        _symbol = symbol;\n\n        // register the supported interfaces to conform to ERC721 via ERC165\n        _registerInterface(_INTERFACE_ID_ERC721_METADATA);\n    }\n\n    /**\n     * @dev Gets the token name.\n     * @return string representing the token name\n     */\n    function name() external view returns (string memory) {\n        return _name;\n    }\n\n    /**\n     * @dev Gets the token symbol.\n     * @return string representing the token symbol\n     */\n    function symbol() external view returns (string memory) {\n        return _symbol;\n    }\n\n    /**\n     * @dev Returns an URI for a given token ID.\n     * Throws if the token ID does not exist. May return an empty string.\n     * @param tokenId uint256 ID of the token to query\n     */\n    function tokenURI(uint256 tokenId) external view returns (string memory) {\n        require(_exists(tokenId), \"ERC721Metadata: URI query for nonexistent token\");\n        return _tokenURIs[tokenId];\n    }\n\n    /**\n     * @dev Internal function to set the token URI for a given token.\n     * Reverts if the token ID does not exist.\n     * @param tokenId uint256 ID of the token to set its URI\n     * @param uri string URI to assign\n     */\n    function _setTokenURI(uint256 tokenId, string memory uri) internal {\n        require(_exists(tokenId), \"ERC721Metadata: URI set of nonexistent token\");\n        _tokenURIs[tokenId] = uri;\n    }\n\n    /**\n     * @dev Internal function to burn a specific token.\n     * Reverts if the token does not exist.\n     * Deprecated, use _burn(uint256) instead.\n     * @param owner owner of the token to burn\n     * @param tokenId uint256 ID of the token being burned by the msg.sender\n     */\n    function _burn(address owner, uint256 tokenId) internal {\n        super._burn(owner, tokenId);\n\n        // Clear metadata (if any)\n        if (bytes(_tokenURIs[tokenId]).length != 0) {\n            delete _tokenURIs[tokenId];\n        }\n    }\n}\n\n// File: @openzeppelin/contracts/token/ERC721/ERC721Full.sol\n\npragma solidity ^0.5.0;\n\n\n\n\n/**\n * @title Full ERC721 Token\n * This implementation includes all the required and some optional functionality of the ERC721 standard\n * Moreover, it includes approve all functionality using operator terminology\n * @dev see https://eips.ethereum.org/EIPS/eip-721\n */\ncontract ERC721Full is ERC721, ERC721Enumerable, ERC721Metadata {\n    constructor (string memory name, string memory symbol) public ERC721Metadata(name, symbol) {\n        // solhint-disable-previous-line no-empty-blocks\n    }\n}\n",
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+                  "nodeType": "EmitStatement",
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+                }
+              ]
+            },
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+            "implemented": true,
+            "kind": "function",
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+            "name": "_mint",
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+              "nodeType": "ParameterList",
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+                  "name": "to",
+                  "nodeType": "VariableDeclaration",
+                  "scope": 768,
+                  "src": "20791:10:1",
+                  "stateVariable": false,
+                  "storageLocation": "default",
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+                    "typeIdentifier": "t_address",
+                    "typeString": "address"
+                  },
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+                    "name": "address",
+                    "nodeType": "ElementaryTypeName",
+                    "src": "20791:7:1",
+                    "stateMutability": "nonpayable",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_address",
+                      "typeString": "address"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                },
+                {
+                  "constant": false,
+                  "id": 727,
+                  "name": "tokenId",
+                  "nodeType": "VariableDeclaration",
+                  "scope": 768,
+                  "src": "20803:15:1",
+                  "stateVariable": false,
+                  "storageLocation": "default",
+                  "typeDescriptions": {
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+                    "typeString": "uint256"
+                  },
+                  "typeName": {
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+                    "name": "uint256",
+                    "nodeType": "ElementaryTypeName",
+                    "src": "20803:7:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_uint256",
+                      "typeString": "uint256"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                }
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+              "src": "20790:29:1"
+            },
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+              "nodeType": "ParameterList",
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+              "src": "20829:0:1"
+            },
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+            "src": "20776:327:1",
+            "stateMutability": "nonpayable",
+            "superFunction": null,
+            "visibility": "internal"
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+              "nodeType": "Block",
+              "src": "21434:268:1",
+              "statements": [
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+                    "arguments": [
+                      {
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+                        "commonType": {
+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        },
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+                        "isConstant": false,
+                        "isLValue": false,
+                        "isPure": false,
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+                          "argumentTypes": null,
+                          "arguments": [
+                            {
+                              "argumentTypes": null,
+                              "id": 777,
+                              "name": "tokenId",
+                              "nodeType": "Identifier",
+                              "overloadedDeclarations": [],
+                              "referencedDeclaration": 772,
+                              "src": "21460:7:1",
+                              "typeDescriptions": {
+                                "typeIdentifier": "t_uint256",
+                                "typeString": "uint256"
+                              }
+                            }
+                          ],
+                          "expression": {
+                            "argumentTypes": [
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+                                "typeString": "uint256"
+                              }
+                            ],
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+                            "name": "ownerOf",
+                            "nodeType": "Identifier",
+                            "overloadedDeclarations": [
+                              480
+                            ],
+                            "referencedDeclaration": 480,
+                            "src": "21452:7:1",
+                            "typeDescriptions": {
+                              "typeIdentifier": "t_function_internal_view$_t_uint256_$returns$_t_address_$",
+                              "typeString": "function (uint256) view returns (address)"
+                            }
+                          },
+                          "id": 778,
+                          "isConstant": false,
+                          "isLValue": false,
+                          "isPure": false,
+                          "kind": "functionCall",
+                          "lValueRequested": false,
+                          "names": [],
+                          "nodeType": "FunctionCall",
+                          "src": "21452:16:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_address",
+                            "typeString": "address"
+                          }
+                        },
+                        "nodeType": "BinaryOperation",
+                        "operator": "==",
+                        "rightExpression": {
+                          "argumentTypes": null,
+                          "id": 779,
+                          "name": "owner",
+                          "nodeType": "Identifier",
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+                          "referencedDeclaration": 770,
+                          "src": "21472:5:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_address",
+                            "typeString": "address"
+                          }
+                        },
+                        "src": "21452:25:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_bool",
+                          "typeString": "bool"
+                        }
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+                        "isPure": true,
+                        "kind": "string",
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+                        "nodeType": "Literal",
+                        "src": "21479:39:1",
+                        "subdenomination": null,
+                        "typeDescriptions": {
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+                          "typeString": "literal_string \"ERC721: burn of token that is not own\""
+                        },
+                        "value": "ERC721: burn of token that is not own"
+                      }
+                    ],
+                    "expression": {
+                      "argumentTypes": [
+                        {
+                          "typeIdentifier": "t_bool",
+                          "typeString": "bool"
+                        },
+                        {
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+                          "typeString": "literal_string \"ERC721: burn of token that is not own\""
+                        }
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+                      "name": "require",
+                      "nodeType": "Identifier",
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+                        1544
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+                      "src": "21444:7:1",
+                      "typeDescriptions": {
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+                      }
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+                    "kind": "functionCall",
+                    "lValueRequested": false,
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+                        "name": "tokenId",
+                        "nodeType": "Identifier",
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+                        "referencedDeclaration": 772,
+                        "src": "21545:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      }
+                    ],
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+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
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+                      "src": "21530:14:1",
+                      "typeDescriptions": {
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+                        "typeString": "function (uint256)"
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+                          "argumentTypes": null,
+                          "id": 788,
+                          "name": "_ownedTokensCount",
+                          "nodeType": "Identifier",
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+                          "referencedDeclaration": 415,
+                          "src": "21564:17:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_mapping$_t_address_$_t_struct$_Counter_$296_storage_$",
+                            "typeString": "mapping(address => struct Counters.Counter storage ref)"
+                          }
+                        },
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+                        "indexExpression": {
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+                          "id": 789,
+                          "name": "owner",
+                          "nodeType": "Identifier",
+                          "overloadedDeclarations": [],
+                          "referencedDeclaration": 770,
+                          "src": "21582:5:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_address",
+                            "typeString": "address"
+                          }
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+                        "isPure": false,
+                        "lValueRequested": false,
+                        "nodeType": "IndexAccess",
+                        "src": "21564:24:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_struct$_Counter_$296_storage",
+                          "typeString": "struct Counters.Counter storage ref"
+                        }
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+                      "isConstant": false,
+                      "isLValue": true,
+                      "isPure": false,
+                      "lValueRequested": false,
+                      "memberName": "decrement",
+                      "nodeType": "MemberAccess",
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+                      "src": "21564:34:1",
+                      "typeDescriptions": {
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+                        "typeString": "function (struct Counters.Counter storage pointer)"
+                      }
+                    },
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+                    "isLValue": false,
+                    "isPure": false,
+                    "kind": "functionCall",
+                    "lValueRequested": false,
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+                    "typeDescriptions": {
+                      "typeIdentifier": "t_tuple$__$",
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+                    "isConstant": false,
+                    "isLValue": false,
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+                      "baseExpression": {
+                        "argumentTypes": null,
+                        "id": 794,
+                        "name": "_tokenOwner",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 407,
+                        "src": "21610:11:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_mapping$_t_uint256_$_t_address_$",
+                          "typeString": "mapping(uint256 => address)"
+                        }
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+                        "id": 795,
+                        "name": "tokenId",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 772,
+                        "src": "21622:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
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+                      "nodeType": "IndexAccess",
+                      "src": "21610:20:1",
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+                        "typeString": "address"
+                      }
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+                    "rightHandSide": {
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+                      "arguments": [
+                        {
+                          "argumentTypes": null,
+                          "hexValue": "30",
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+                          "isConstant": false,
+                          "isLValue": false,
+                          "isPure": true,
+                          "kind": "number",
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+                          "nodeType": "Literal",
+                          "src": "21641:1:1",
+                          "subdenomination": null,
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_rational_0_by_1",
+                            "typeString": "int_const 0"
+                          },
+                          "value": "0"
+                        }
+                      ],
+                      "expression": {
+                        "argumentTypes": [
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+                            "typeString": "int_const 0"
+                          }
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+                        "isLValue": false,
+                        "isPure": true,
+                        "lValueRequested": false,
+                        "nodeType": "ElementaryTypeNameExpression",
+                        "src": "21633:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_type$_t_address_$",
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+                        },
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+                      },
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+                      "names": [],
+                      "nodeType": "FunctionCall",
+                      "src": "21633:10:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_address_payable",
+                        "typeString": "address payable"
+                      }
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+                    "src": "21610:33:1",
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+                      "typeIdentifier": "t_address",
+                      "typeString": "address"
+                    }
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+                  "src": "21610:33:1"
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+                    "arguments": [
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+                        "argumentTypes": null,
+                        "id": 803,
+                        "name": "owner",
+                        "nodeType": "Identifier",
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+                        "referencedDeclaration": 770,
+                        "src": "21668:5:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        }
+                      },
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+                        "arguments": [
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+                            "id": 805,
+                            "isConstant": false,
+                            "isLValue": false,
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+                            "kind": "number",
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+                            "nodeType": "Literal",
+                            "src": "21683:1:1",
+                            "subdenomination": null,
+                            "typeDescriptions": {
+                              "typeIdentifier": "t_rational_0_by_1",
+                              "typeString": "int_const 0"
+                            },
+                            "value": "0"
+                          }
+                        ],
+                        "expression": {
+                          "argumentTypes": [
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+                              "typeString": "int_const 0"
+                            }
+                          ],
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+                          "isConstant": false,
+                          "isLValue": false,
+                          "isPure": true,
+                          "lValueRequested": false,
+                          "nodeType": "ElementaryTypeNameExpression",
+                          "src": "21675:7:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_type$_t_address_$",
+                            "typeString": "type(address)"
+                          },
+                          "typeName": "address"
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+                        "isConstant": false,
+                        "isLValue": false,
+                        "isPure": true,
+                        "kind": "typeConversion",
+                        "lValueRequested": false,
+                        "names": [],
+                        "nodeType": "FunctionCall",
+                        "src": "21675:10:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_address_payable",
+                          "typeString": "address payable"
+                        }
+                      },
+                      {
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+                        "id": 807,
+                        "name": "tokenId",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 772,
+                        "src": "21687:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      }
+                    ],
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+                      "argumentTypes": [
+                        {
+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        },
+                        {
+                          "typeIdentifier": "t_address_payable",
+                          "typeString": "address payable"
+                        },
+                        {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      ],
+                      "id": 802,
+                      "name": "Transfer",
+                      "nodeType": "Identifier",
+                      "overloadedDeclarations": [],
+                      "referencedDeclaration": 34,
+                      "src": "21659:8:1",
+                      "typeDescriptions": {
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+                    "src": "21659:36:1",
+                    "typeDescriptions": {
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+                      "typeString": "tuple()"
+                    }
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+                  "nodeType": "EmitStatement",
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+                }
+              ]
+            },
+            "documentation": "@dev Internal function to burn a specific token.\nReverts if the token does not exist.\nDeprecated, use _burn(uint256) instead.\n@param owner owner of the token to burn\n@param tokenId uint256 ID of the token being burned",
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+            "implemented": true,
+            "kind": "function",
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+                  "name": "owner",
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+                  "storageLocation": "default",
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+                    "typeString": "address"
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+                    "name": "address",
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+                      "typeIdentifier": "t_address",
+                      "typeString": "address"
+                    }
+                  },
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+                  "visibility": "internal"
+                },
+                {
+                  "constant": false,
+                  "id": 772,
+                  "name": "tokenId",
+                  "nodeType": "VariableDeclaration",
+                  "scope": 811,
+                  "src": "21408:15:1",
+                  "stateVariable": false,
+                  "storageLocation": "default",
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+                    "typeString": "uint256"
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+                      "typeString": "uint256"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                }
+              ],
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+              "nodeType": "ParameterList",
+              "parameters": [],
+              "src": "21434:0:1"
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+            "src": "21378:324:1",
+            "stateMutability": "nonpayable",
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+            "visibility": "internal"
+          },
+          {
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+              "nodeType": "Block",
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+                    "arguments": [
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+                        "arguments": [
+                          {
+                            "argumentTypes": null,
+                            "id": 818,
+                            "name": "tokenId",
+                            "nodeType": "Identifier",
+                            "overloadedDeclarations": [],
+                            "referencedDeclaration": 813,
+                            "src": "21948:7:1",
+                            "typeDescriptions": {
+                              "typeIdentifier": "t_uint256",
+                              "typeString": "uint256"
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+                            {
+                              "typeIdentifier": "t_uint256",
+                              "typeString": "uint256"
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+                          "name": "ownerOf",
+                          "nodeType": "Identifier",
+                          "overloadedDeclarations": [
+                            480
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+                        "src": "22770:4:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        }
+                      },
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+                        "name": "to",
+                        "nodeType": "Identifier",
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+                        "src": "22776:2:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        }
+                      },
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+                        "argumentTypes": null,
+                        "id": 876,
+                        "name": "tokenId",
+                        "nodeType": "Identifier",
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+                        "src": "22780:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      }
+                    ],
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+                      "argumentTypes": [
+                        {
+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        },
+                        {
+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        },
+                        {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      ],
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+                      "name": "Transfer",
+                      "nodeType": "Identifier",
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+                      "referencedDeclaration": 34,
+                      "src": "22761:8:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_function_event_nonpayable$_t_address_$_t_address_$_t_uint256_$returns$__$",
+                        "typeString": "function (address,address,uint256)"
+                      }
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+                    "kind": "functionCall",
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+                    "names": [],
+                    "nodeType": "FunctionCall",
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+                      "typeString": "tuple()"
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+                  "nodeType": "EmitStatement",
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+                }
+              ]
+            },
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+            "kind": "function",
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+            "name": "_transferFrom",
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+                    "typeString": "address"
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+                      "typeIdentifier": "t_address",
+                      "typeString": "address"
+                    }
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+                    "typeString": "address"
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+                    "name": "address",
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+                      "typeString": "address"
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+                    "typeString": "uint256"
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+                    "name": "uint256",
+                    "nodeType": "ElementaryTypeName",
+                    "src": "22397:7:1",
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+                      "typeString": "uint256"
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+                  "visibility": "internal"
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+            "visibility": "internal"
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+                          "name": "to",
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+                          "overloadedDeclarations": [],
+                          "referencedDeclaration": 884,
+                          "src": "23514:2:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_address",
+                            "typeString": "address"
+                          }
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+                          "typeDescriptions": {
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+                      "storageLocation": "default",
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+                        "typeString": "bytes4"
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+                        "name": "bytes4",
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+                          "typeIdentifier": "t_bytes4",
+                          "typeString": "bytes4"
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+                        "expression": {
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+                          "id": 907,
+                          "name": "msg",
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+                          "src": "23630:3:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_magic_message",
+                            "typeString": "msg"
+                          }
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+                        "isLValue": false,
+                        "isPure": false,
+                        "lValueRequested": false,
+                        "memberName": "sender",
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+                        "src": "23630:10:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_address_payable",
+                          "typeString": "address payable"
+                        }
+                      },
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+                        "id": 909,
+                        "name": "from",
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+                        "src": "23642:4:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        }
+                      },
+                      {
+                        "argumentTypes": null,
+                        "id": 910,
+                        "name": "tokenId",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
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+                        "src": "23648:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      },
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+                        "id": 911,
+                        "name": "_data",
+                        "nodeType": "Identifier",
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+                        "src": "23657:5:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_bytes_memory_ptr",
+                          "typeString": "bytes memory"
+                        }
+                      }
+                    ],
+                    "expression": {
+                      "argumentTypes": [
+                        {
+                          "typeIdentifier": "t_address_payable",
+                          "typeString": "address payable"
+                        },
+                        {
+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        },
+                        {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        },
+                        {
+                          "typeIdentifier": "t_bytes_memory_ptr",
+                          "typeString": "bytes memory"
+                        }
+                      ],
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+                        "arguments": [
+                          {
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+                            "id": 904,
+                            "name": "to",
+                            "nodeType": "Identifier",
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+                            "src": "23609:2:1",
+                            "typeDescriptions": {
+                              "typeIdentifier": "t_address",
+                              "typeString": "address"
+                            }
+                          }
+                        ],
+                        "expression": {
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+                            {
+                              "typeIdentifier": "t_address",
+                              "typeString": "address"
+                            }
+                          ],
+                          "id": 903,
+                          "name": "IERC721Receiver",
+                          "nodeType": "Identifier",
+                          "overloadedDeclarations": [],
+                          "referencedDeclaration": 139,
+                          "src": "23593:15:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_type$_t_contract$_IERC721Receiver_$139_$",
+                            "typeString": "type(contract IERC721Receiver)"
+                          }
+                        },
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+                        "isLValue": false,
+                        "isPure": false,
+                        "kind": "typeConversion",
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+                        "names": [],
+                        "nodeType": "FunctionCall",
+                        "src": "23593:19:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_contract$_IERC721Receiver_$139",
+                          "typeString": "contract IERC721Receiver"
+                        }
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+                      "memberName": "onERC721Received",
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+                      "src": "23593:36:1",
+                      "typeDescriptions": {
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+                        "typeString": "function (address,address,uint256,bytes memory) external returns (bytes4)"
+                      }
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+                      "typeIdentifier": "t_bytes4",
+                      "typeString": "bytes4"
+                    }
+                  },
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+                  "src": "23577:86:1"
+                },
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+                        "argumentTypes": null,
+                        "commonType": {
+                          "typeIdentifier": "t_bytes4",
+                          "typeString": "bytes4"
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+                        "isConstant": false,
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+                        "isPure": false,
+                        "lValueRequested": false,
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+                          "name": "retval",
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+                          "referencedDeclaration": 902,
+                          "src": "23681:6:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_bytes4",
+                            "typeString": "bytes4"
+                          }
+                        },
+                        "nodeType": "BinaryOperation",
+                        "operator": "==",
+                        "rightExpression": {
+                          "argumentTypes": null,
+                          "id": 915,
+                          "name": "_ERC721_RECEIVED",
+                          "nodeType": "Identifier",
+                          "overloadedDeclarations": [],
+                          "referencedDeclaration": 403,
+                          "src": "23691:16:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_bytes4",
+                            "typeString": "bytes4"
+                          }
+                        },
+                        "src": "23681:26:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_bool",
+                          "typeString": "bool"
+                        }
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+                    "isInlineArray": false,
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+                  "id": 918,
+                  "nodeType": "Return",
+                  "src": "23673:35:1"
+                }
+              ]
+            },
+            "documentation": "@dev Internal function to invoke `onERC721Received` on a target address.\nThe call is not executed if the target address is not a contract.\n     * This function is deprecated.\n@param from address representing the previous owner of the given token ID\n@param to target address that will receive the tokens\n@param tokenId uint256 ID of the token to be transferred\n@param _data bytes optional data to send along with the call\n@return bool whether the call correctly returned the expected magic value",
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+            "implemented": true,
+            "kind": "function",
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+            "name": "_checkOnERC721Received",
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+                  "storageLocation": "default",
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+                  },
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+                    "name": "address",
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+                    }
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+                  "src": "23414:10:1",
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+                  "storageLocation": "default",
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+                    "typeIdentifier": "t_address",
+                    "typeString": "address"
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+                    "nodeType": "ElementaryTypeName",
+                    "src": "23414:7:1",
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+                      "typeString": "address"
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+                {
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+                  "src": "23426:15:1",
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+                  "src": "23443:18:1",
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+                  "storageLocation": "memory",
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+                    "typeString": "bytes"
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+                      "typeString": "bytes"
+                    }
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+                  "visibility": "internal"
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+                  "src": "23489:4:1",
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+                  "visibility": "internal"
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+                        "id": 925,
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+                        "typeDescriptions": {
+                          "typeIdentifier": "t_mapping$_t_uint256_$_t_address_$",
+                          "typeString": "mapping(uint256 => address)"
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+                        "src": "23956:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
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+                    "baseExpression": {
+                      "argumentTypes": null,
+                      "id": 1052,
+                      "name": "_allTokens",
+                      "nodeType": "Identifier",
+                      "overloadedDeclarations": [],
+                      "referencedDeclaration": 988,
+                      "src": "27266:10:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_array$_t_uint256_$dyn_storage",
+                        "typeString": "uint256[] storage ref"
+                      }
+                    },
+                    "id": 1054,
+                    "indexExpression": {
+                      "argumentTypes": null,
+                      "id": 1053,
+                      "name": "index",
+                      "nodeType": "Identifier",
+                      "overloadedDeclarations": [],
+                      "referencedDeclaration": 1039,
+                      "src": "27277:5:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_uint256",
+                        "typeString": "uint256"
+                      }
+                    },
+                    "isConstant": false,
+                    "isLValue": true,
+                    "isPure": false,
+                    "lValueRequested": false,
+                    "nodeType": "IndexAccess",
+                    "src": "27266:17:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_uint256",
+                      "typeString": "uint256"
+                    }
+                  },
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+                  "id": 1055,
+                  "nodeType": "Return",
+                  "src": "27259:24:1"
+                }
+              ]
+            },
+            "documentation": "@dev Gets the token ID at a given index of all the tokens in this contract\nReverts if the index is greater or equal to the total number of tokens.\n@param index uint256 representing the index to be accessed of the tokens list\n@return uint256 token ID at the given index of the tokens list",
+            "id": 1057,
+            "implemented": true,
+            "kind": "function",
+            "modifiers": [],
+            "name": "tokenByIndex",
+            "nodeType": "FunctionDefinition",
+            "parameters": {
+              "id": 1040,
+              "nodeType": "ParameterList",
+              "parameters": [
+                {
+                  "constant": false,
+                  "id": 1039,
+                  "name": "index",
+                  "nodeType": "VariableDeclaration",
+                  "scope": 1057,
+                  "src": "27116:13:1",
+                  "stateVariable": false,
+                  "storageLocation": "default",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_uint256",
+                    "typeString": "uint256"
+                  },
+                  "typeName": {
+                    "id": 1038,
+                    "name": "uint256",
+                    "nodeType": "ElementaryTypeName",
+                    "src": "27116:7:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_uint256",
+                      "typeString": "uint256"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                }
+              ],
+              "src": "27115:15:1"
+            },
+            "returnParameters": {
+              "id": 1043,
+              "nodeType": "ParameterList",
+              "parameters": [
+                {
+                  "constant": false,
+                  "id": 1042,
+                  "name": "",
+                  "nodeType": "VariableDeclaration",
+                  "scope": 1057,
+                  "src": "27152:7:1",
+                  "stateVariable": false,
+                  "storageLocation": "default",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_uint256",
+                    "typeString": "uint256"
+                  },
+                  "typeName": {
+                    "id": 1041,
+                    "name": "uint256",
+                    "nodeType": "ElementaryTypeName",
+                    "src": "27152:7:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_uint256",
+                      "typeString": "uint256"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                }
+              ],
+              "src": "27151:9:1"
+            },
+            "scope": 1302,
+            "src": "27094:196:1",
+            "stateMutability": "view",
+            "superFunction": 968,
+            "visibility": "public"
+          },
+          {
+            "body": {
+              "id": 1084,
+              "nodeType": "Block",
+              "src": "27740:164:1",
+              "statements": [
+                {
+                  "expression": {
+                    "argumentTypes": null,
+                    "arguments": [
+                      {
+                        "argumentTypes": null,
+                        "id": 1069,
+                        "name": "from",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 1059,
+                        "src": "27770:4:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        }
+                      },
+                      {
+                        "argumentTypes": null,
+                        "id": 1070,
+                        "name": "to",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 1061,
+                        "src": "27776:2:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        }
+                      },
+                      {
+                        "argumentTypes": null,
+                        "id": 1071,
+                        "name": "tokenId",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 1063,
+                        "src": "27780:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      }
+                    ],
+                    "expression": {
+                      "argumentTypes": [
+                        {
+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        },
+                        {
+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        },
+                        {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      ],
+                      "expression": {
+                        "argumentTypes": null,
+                        "id": 1066,
+                        "name": "super",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 1572,
+                        "src": "27750:5:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_super$_ERC721Enumerable_$1302",
+                          "typeString": "contract super ERC721Enumerable"
+                        }
+                      },
+                      "id": 1068,
+                      "isConstant": false,
+                      "isLValue": false,
+                      "isPure": false,
+                      "lValueRequested": false,
+                      "memberName": "_transferFrom",
+                      "nodeType": "MemberAccess",
+                      "referencedDeclaration": 880,
+                      "src": "27750:19:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_function_internal_nonpayable$_t_address_$_t_address_$_t_uint256_$returns$__$",
+                        "typeString": "function (address,address,uint256)"
+                      }
+                    },
+                    "id": 1072,
+                    "isConstant": false,
+                    "isLValue": false,
+                    "isPure": false,
+                    "kind": "functionCall",
+                    "lValueRequested": false,
+                    "names": [],
+                    "nodeType": "FunctionCall",
+                    "src": "27750:38:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_tuple$__$",
+                      "typeString": "tuple()"
+                    }
+                  },
+                  "id": 1073,
+                  "nodeType": "ExpressionStatement",
+                  "src": "27750:38:1"
+                },
+                {
+                  "expression": {
+                    "argumentTypes": null,
+                    "arguments": [
+                      {
+                        "argumentTypes": null,
+                        "id": 1075,
+                        "name": "from",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 1059,
+                        "src": "27832:4:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        }
+                      },
+                      {
+                        "argumentTypes": null,
+                        "id": 1076,
+                        "name": "tokenId",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 1063,
+                        "src": "27838:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      }
+                    ],
+                    "expression": {
+                      "argumentTypes": [
+                        {
+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        },
+                        {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      ],
+                      "id": 1074,
+                      "name": "_removeTokenFromOwnerEnumeration",
+                      "nodeType": "Identifier",
+                      "overloadedDeclarations": [],
+                      "referencedDeclaration": 1252,
+                      "src": "27799:32:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_function_internal_nonpayable$_t_address_$_t_uint256_$returns$__$",
+                        "typeString": "function (address,uint256)"
+                      }
+                    },
+                    "id": 1077,
+                    "isConstant": false,
+                    "isLValue": false,
+                    "isPure": false,
+                    "kind": "functionCall",
+                    "lValueRequested": false,
+                    "names": [],
+                    "nodeType": "FunctionCall",
+                    "src": "27799:47:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_tuple$__$",
+                      "typeString": "tuple()"
+                    }
+                  },
+                  "id": 1078,
+                  "nodeType": "ExpressionStatement",
+                  "src": "27799:47:1"
+                },
+                {
+                  "expression": {
+                    "argumentTypes": null,
+                    "arguments": [
+                      {
+                        "argumentTypes": null,
+                        "id": 1080,
+                        "name": "to",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 1061,
+                        "src": "27885:2:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        }
+                      },
+                      {
+                        "argumentTypes": null,
+                        "id": 1081,
+                        "name": "tokenId",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 1063,
+                        "src": "27889:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      }
+                    ],
+                    "expression": {
+                      "argumentTypes": [
+                        {
+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        },
+                        {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      ],
+                      "id": 1079,
+                      "name": "_addTokenToOwnerEnumeration",
+                      "nodeType": "Identifier",
+                      "overloadedDeclarations": [],
+                      "referencedDeclaration": 1176,
+                      "src": "27857:27:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_function_internal_nonpayable$_t_address_$_t_uint256_$returns$__$",
+                        "typeString": "function (address,uint256)"
+                      }
+                    },
+                    "id": 1082,
+                    "isConstant": false,
+                    "isLValue": false,
+                    "isPure": false,
+                    "kind": "functionCall",
+                    "lValueRequested": false,
+                    "names": [],
+                    "nodeType": "FunctionCall",
+                    "src": "27857:40:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_tuple$__$",
+                      "typeString": "tuple()"
+                    }
+                  },
+                  "id": 1083,
+                  "nodeType": "ExpressionStatement",
+                  "src": "27857:40:1"
+                }
+              ]
+            },
+            "documentation": "@dev Internal function to transfer ownership of a given token ID to another address.\nAs opposed to transferFrom, this imposes no restrictions on msg.sender.\n@param from current owner of the token\n@param to address to receive the ownership of the given token ID\n@param tokenId uint256 ID of the token to be transferred",
+            "id": 1085,
+            "implemented": true,
+            "kind": "function",
+            "modifiers": [],
+            "name": "_transferFrom",
+            "nodeType": "FunctionDefinition",
+            "parameters": {
+              "id": 1064,
+              "nodeType": "ParameterList",
+              "parameters": [
+                {
+                  "constant": false,
+                  "id": 1059,
+                  "name": "from",
+                  "nodeType": "VariableDeclaration",
+                  "scope": 1085,
+                  "src": "27688:12:1",
+                  "stateVariable": false,
+                  "storageLocation": "default",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_address",
+                    "typeString": "address"
+                  },
+                  "typeName": {
+                    "id": 1058,
+                    "name": "address",
+                    "nodeType": "ElementaryTypeName",
+                    "src": "27688:7:1",
+                    "stateMutability": "nonpayable",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_address",
+                      "typeString": "address"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                },
+                {
+                  "constant": false,
+                  "id": 1061,
+                  "name": "to",
+                  "nodeType": "VariableDeclaration",
+                  "scope": 1085,
+                  "src": "27702:10:1",
+                  "stateVariable": false,
+                  "storageLocation": "default",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_address",
+                    "typeString": "address"
+                  },
+                  "typeName": {
+                    "id": 1060,
+                    "name": "address",
+                    "nodeType": "ElementaryTypeName",
+                    "src": "27702:7:1",
+                    "stateMutability": "nonpayable",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_address",
+                      "typeString": "address"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                },
+                {
+                  "constant": false,
+                  "id": 1063,
+                  "name": "tokenId",
+                  "nodeType": "VariableDeclaration",
+                  "scope": 1085,
+                  "src": "27714:15:1",
+                  "stateVariable": false,
+                  "storageLocation": "default",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_uint256",
+                    "typeString": "uint256"
+                  },
+                  "typeName": {
+                    "id": 1062,
+                    "name": "uint256",
+                    "nodeType": "ElementaryTypeName",
+                    "src": "27714:7:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_uint256",
+                      "typeString": "uint256"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                }
+              ],
+              "src": "27687:43:1"
+            },
+            "returnParameters": {
+              "id": 1065,
+              "nodeType": "ParameterList",
+              "parameters": [],
+              "src": "27740:0:1"
+            },
+            "scope": 1302,
+            "src": "27665:239:1",
+            "stateMutability": "nonpayable",
+            "superFunction": 880,
+            "visibility": "internal"
+          },
+          {
+            "body": {
+              "id": 1108,
+              "nodeType": "Block",
+              "src": "28214:143:1",
+              "statements": [
+                {
+                  "expression": {
+                    "argumentTypes": null,
+                    "arguments": [
+                      {
+                        "argumentTypes": null,
+                        "id": 1095,
+                        "name": "to",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 1087,
+                        "src": "28236:2:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        }
+                      },
+                      {
+                        "argumentTypes": null,
+                        "id": 1096,
+                        "name": "tokenId",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 1089,
+                        "src": "28240:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      }
+                    ],
+                    "expression": {
+                      "argumentTypes": [
+                        {
+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        },
+                        {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      ],
+                      "expression": {
+                        "argumentTypes": null,
+                        "id": 1092,
+                        "name": "super",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 1572,
+                        "src": "28224:5:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_super$_ERC721Enumerable_$1302",
+                          "typeString": "contract super ERC721Enumerable"
+                        }
+                      },
+                      "id": 1094,
+                      "isConstant": false,
+                      "isLValue": false,
+                      "isPure": false,
+                      "lValueRequested": false,
+                      "memberName": "_mint",
+                      "nodeType": "MemberAccess",
+                      "referencedDeclaration": 768,
+                      "src": "28224:11:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_function_internal_nonpayable$_t_address_$_t_uint256_$returns$__$",
+                        "typeString": "function (address,uint256)"
+                      }
+                    },
+                    "id": 1097,
+                    "isConstant": false,
+                    "isLValue": false,
+                    "isPure": false,
+                    "kind": "functionCall",
+                    "lValueRequested": false,
+                    "names": [],
+                    "nodeType": "FunctionCall",
+                    "src": "28224:24:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_tuple$__$",
+                      "typeString": "tuple()"
+                    }
+                  },
+                  "id": 1098,
+                  "nodeType": "ExpressionStatement",
+                  "src": "28224:24:1"
+                },
+                {
+                  "expression": {
+                    "argumentTypes": null,
+                    "arguments": [
+                      {
+                        "argumentTypes": null,
+                        "id": 1100,
+                        "name": "to",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 1087,
+                        "src": "28287:2:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        }
+                      },
+                      {
+                        "argumentTypes": null,
+                        "id": 1101,
+                        "name": "tokenId",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 1089,
+                        "src": "28291:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      }
+                    ],
+                    "expression": {
+                      "argumentTypes": [
+                        {
+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        },
+                        {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      ],
+                      "id": 1099,
+                      "name": "_addTokenToOwnerEnumeration",
+                      "nodeType": "Identifier",
+                      "overloadedDeclarations": [],
+                      "referencedDeclaration": 1176,
+                      "src": "28259:27:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_function_internal_nonpayable$_t_address_$_t_uint256_$returns$__$",
+                        "typeString": "function (address,uint256)"
+                      }
+                    },
+                    "id": 1102,
+                    "isConstant": false,
+                    "isLValue": false,
+                    "isPure": false,
+                    "kind": "functionCall",
+                    "lValueRequested": false,
+                    "names": [],
+                    "nodeType": "FunctionCall",
+                    "src": "28259:40:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_tuple$__$",
+                      "typeString": "tuple()"
+                    }
+                  },
+                  "id": 1103,
+                  "nodeType": "ExpressionStatement",
+                  "src": "28259:40:1"
+                },
+                {
+                  "expression": {
+                    "argumentTypes": null,
+                    "arguments": [
+                      {
+                        "argumentTypes": null,
+                        "id": 1105,
+                        "name": "tokenId",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 1089,
+                        "src": "28342:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      }
+                    ],
+                    "expression": {
+                      "argumentTypes": [
+                        {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      ],
+                      "id": 1104,
+                      "name": "_addTokenToAllTokensEnumeration",
+                      "nodeType": "Identifier",
+                      "overloadedDeclarations": [],
+                      "referencedDeclaration": 1195,
+                      "src": "28310:31:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_function_internal_nonpayable$_t_uint256_$returns$__$",
+                        "typeString": "function (uint256)"
+                      }
+                    },
+                    "id": 1106,
+                    "isConstant": false,
+                    "isLValue": false,
+                    "isPure": false,
+                    "kind": "functionCall",
+                    "lValueRequested": false,
+                    "names": [],
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+                    "src": "28310:40:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_tuple$__$",
+                      "typeString": "tuple()"
+                    }
+                  },
+                  "id": 1107,
+                  "nodeType": "ExpressionStatement",
+                  "src": "28310:40:1"
+                }
+              ]
+            },
+            "documentation": "@dev Internal function to mint a new token.\nReverts if the given token ID already exists.\n@param to address the beneficiary that will own the minted token\n@param tokenId uint256 ID of the token to be minted",
+            "id": 1109,
+            "implemented": true,
+            "kind": "function",
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+            "name": "_mint",
+            "nodeType": "FunctionDefinition",
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+                  "name": "to",
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+                  "scope": 1109,
+                  "src": "28176:10:1",
+                  "stateVariable": false,
+                  "storageLocation": "default",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_address",
+                    "typeString": "address"
+                  },
+                  "typeName": {
+                    "id": 1086,
+                    "name": "address",
+                    "nodeType": "ElementaryTypeName",
+                    "src": "28176:7:1",
+                    "stateMutability": "nonpayable",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_address",
+                      "typeString": "address"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                },
+                {
+                  "constant": false,
+                  "id": 1089,
+                  "name": "tokenId",
+                  "nodeType": "VariableDeclaration",
+                  "scope": 1109,
+                  "src": "28188:15:1",
+                  "stateVariable": false,
+                  "storageLocation": "default",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_uint256",
+                    "typeString": "uint256"
+                  },
+                  "typeName": {
+                    "id": 1088,
+                    "name": "uint256",
+                    "nodeType": "ElementaryTypeName",
+                    "src": "28188:7:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_uint256",
+                      "typeString": "uint256"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                }
+              ],
+              "src": "28175:29:1"
+            },
+            "returnParameters": {
+              "id": 1091,
+              "nodeType": "ParameterList",
+              "parameters": [],
+              "src": "28214:0:1"
+            },
+            "scope": 1302,
+            "src": "28161:196:1",
+            "stateMutability": "nonpayable",
+            "superFunction": 768,
+            "visibility": "internal"
+          },
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+              "src": "28688:308:1",
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+                    "arguments": [
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+                        "name": "owner",
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+                        "referencedDeclaration": 1111,
+                        "src": "28710:5:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        }
+                      },
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+                        "id": 1120,
+                        "name": "tokenId",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 1113,
+                        "src": "28717:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
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+                    ],
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+                      "argumentTypes": [
+                        {
+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        },
+                        {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
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+                        "name": "super",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 1572,
+                        "src": "28698:5:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_super$_ERC721Enumerable_$1302",
+                          "typeString": "contract super ERC721Enumerable"
+                        }
+                      },
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+                      "isConstant": false,
+                      "isLValue": false,
+                      "isPure": false,
+                      "lValueRequested": false,
+                      "memberName": "_burn",
+                      "nodeType": "MemberAccess",
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+                      "src": "28698:11:1",
+                      "typeDescriptions": {
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+                        "typeString": "function (address,uint256)"
+                      }
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+                    "kind": "functionCall",
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+                    "src": "28698:27:1",
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+                      "typeString": "tuple()"
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+                        "name": "owner",
+                        "nodeType": "Identifier",
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+                        "referencedDeclaration": 1111,
+                        "src": "28769:5:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        }
+                      },
+                      {
+                        "argumentTypes": null,
+                        "id": 1125,
+                        "name": "tokenId",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 1113,
+                        "src": "28776:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      }
+                    ],
+                    "expression": {
+                      "argumentTypes": [
+                        {
+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        },
+                        {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      ],
+                      "id": 1123,
+                      "name": "_removeTokenFromOwnerEnumeration",
+                      "nodeType": "Identifier",
+                      "overloadedDeclarations": [],
+                      "referencedDeclaration": 1252,
+                      "src": "28736:32:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_function_internal_nonpayable$_t_address_$_t_uint256_$returns$__$",
+                        "typeString": "function (address,uint256)"
+                      }
+                    },
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+                    "isConstant": false,
+                    "isLValue": false,
+                    "isPure": false,
+                    "kind": "functionCall",
+                    "lValueRequested": false,
+                    "names": [],
+                    "nodeType": "FunctionCall",
+                    "src": "28736:48:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_tuple$__$",
+                      "typeString": "tuple()"
+                    }
+                  },
+                  "id": 1127,
+                  "nodeType": "ExpressionStatement",
+                  "src": "28736:48:1"
+                },
+                {
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+                    "id": 1132,
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+                    "isLValue": false,
+                    "isPure": false,
+                    "lValueRequested": false,
+                    "leftHandSide": {
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+                      "baseExpression": {
+                        "argumentTypes": null,
+                        "id": 1128,
+                        "name": "_ownedTokensIndex",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 985,
+                        "src": "28903:17:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_mapping$_t_uint256_$_t_uint256_$",
+                          "typeString": "mapping(uint256 => uint256)"
+                        }
+                      },
+                      "id": 1130,
+                      "indexExpression": {
+                        "argumentTypes": null,
+                        "id": 1129,
+                        "name": "tokenId",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 1113,
+                        "src": "28921:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      },
+                      "isConstant": false,
+                      "isLValue": true,
+                      "isPure": false,
+                      "lValueRequested": true,
+                      "nodeType": "IndexAccess",
+                      "src": "28903:26:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_uint256",
+                        "typeString": "uint256"
+                      }
+                    },
+                    "nodeType": "Assignment",
+                    "operator": "=",
+                    "rightHandSide": {
+                      "argumentTypes": null,
+                      "hexValue": "30",
+                      "id": 1131,
+                      "isConstant": false,
+                      "isLValue": false,
+                      "isPure": true,
+                      "kind": "number",
+                      "lValueRequested": false,
+                      "nodeType": "Literal",
+                      "src": "28932:1:1",
+                      "subdenomination": null,
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_rational_0_by_1",
+                        "typeString": "int_const 0"
+                      },
+                      "value": "0"
+                    },
+                    "src": "28903:30:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_uint256",
+                      "typeString": "uint256"
+                    }
+                  },
+                  "id": 1133,
+                  "nodeType": "ExpressionStatement",
+                  "src": "28903:30:1"
+                },
+                {
+                  "expression": {
+                    "argumentTypes": null,
+                    "arguments": [
+                      {
+                        "argumentTypes": null,
+                        "id": 1135,
+                        "name": "tokenId",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 1113,
+                        "src": "28981:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      }
+                    ],
+                    "expression": {
+                      "argumentTypes": [
+                        {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      ],
+                      "id": 1134,
+                      "name": "_removeTokenFromAllTokensEnumeration",
+                      "nodeType": "Identifier",
+                      "overloadedDeclarations": [],
+                      "referencedDeclaration": 1301,
+                      "src": "28944:36:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_function_internal_nonpayable$_t_uint256_$returns$__$",
+                        "typeString": "function (uint256)"
+                      }
+                    },
+                    "id": 1136,
+                    "isConstant": false,
+                    "isLValue": false,
+                    "isPure": false,
+                    "kind": "functionCall",
+                    "lValueRequested": false,
+                    "names": [],
+                    "nodeType": "FunctionCall",
+                    "src": "28944:45:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_tuple$__$",
+                      "typeString": "tuple()"
+                    }
+                  },
+                  "id": 1137,
+                  "nodeType": "ExpressionStatement",
+                  "src": "28944:45:1"
+                }
+              ]
+            },
+            "documentation": "@dev Internal function to burn a specific token.\nReverts if the token does not exist.\nDeprecated, use _burn(uint256) instead.\n@param owner owner of the token to burn\n@param tokenId uint256 ID of the token being burned",
+            "id": 1139,
+            "implemented": true,
+            "kind": "function",
+            "modifiers": [],
+            "name": "_burn",
+            "nodeType": "FunctionDefinition",
+            "parameters": {
+              "id": 1114,
+              "nodeType": "ParameterList",
+              "parameters": [
+                {
+                  "constant": false,
+                  "id": 1111,
+                  "name": "owner",
+                  "nodeType": "VariableDeclaration",
+                  "scope": 1139,
+                  "src": "28647:13:1",
+                  "stateVariable": false,
+                  "storageLocation": "default",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_address",
+                    "typeString": "address"
+                  },
+                  "typeName": {
+                    "id": 1110,
+                    "name": "address",
+                    "nodeType": "ElementaryTypeName",
+                    "src": "28647:7:1",
+                    "stateMutability": "nonpayable",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_address",
+                      "typeString": "address"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                },
+                {
+                  "constant": false,
+                  "id": 1113,
+                  "name": "tokenId",
+                  "nodeType": "VariableDeclaration",
+                  "scope": 1139,
+                  "src": "28662:15:1",
+                  "stateVariable": false,
+                  "storageLocation": "default",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_uint256",
+                    "typeString": "uint256"
+                  },
+                  "typeName": {
+                    "id": 1112,
+                    "name": "uint256",
+                    "nodeType": "ElementaryTypeName",
+                    "src": "28662:7:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_uint256",
+                      "typeString": "uint256"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                }
+              ],
+              "src": "28646:32:1"
+            },
+            "returnParameters": {
+              "id": 1115,
+              "nodeType": "ParameterList",
+              "parameters": [],
+              "src": "28688:0:1"
+            },
+            "scope": 1302,
+            "src": "28632:364:1",
+            "stateMutability": "nonpayable",
+            "superFunction": 811,
+            "visibility": "internal"
+          },
+          {
+            "body": {
+              "id": 1151,
+              "nodeType": "Block",
+              "src": "29282:43:1",
+              "statements": [
+                {
+                  "expression": {
+                    "argumentTypes": null,
+                    "baseExpression": {
+                      "argumentTypes": null,
+                      "id": 1147,
+                      "name": "_ownedTokens",
+                      "nodeType": "Identifier",
+                      "overloadedDeclarations": [],
+                      "referencedDeclaration": 981,
+                      "src": "29299:12:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_mapping$_t_address_$_t_array$_t_uint256_$dyn_storage_$",
+                        "typeString": "mapping(address => uint256[] storage ref)"
+                      }
+                    },
+                    "id": 1149,
+                    "indexExpression": {
+                      "argumentTypes": null,
+                      "id": 1148,
+                      "name": "owner",
+                      "nodeType": "Identifier",
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+                      "referencedDeclaration": 1141,
+                      "src": "29312:5:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_address",
+                        "typeString": "address"
+                      }
+                    },
+                    "isConstant": false,
+                    "isLValue": true,
+                    "isPure": false,
+                    "lValueRequested": false,
+                    "nodeType": "IndexAccess",
+                    "src": "29299:19:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_array$_t_uint256_$dyn_storage",
+                      "typeString": "uint256[] storage ref"
+                    }
+                  },
+                  "functionReturnParameters": 1146,
+                  "id": 1150,
+                  "nodeType": "Return",
+                  "src": "29292:26:1"
+                }
+              ]
+            },
+            "documentation": "@dev Gets the list of token IDs of the requested owner.\n@param owner address owning the tokens\n@return uint256[] List of token IDs owned by the requested address",
+            "id": 1152,
+            "implemented": true,
+            "kind": "function",
+            "modifiers": [],
+            "name": "_tokensOfOwner",
+            "nodeType": "FunctionDefinition",
+            "parameters": {
+              "id": 1142,
+              "nodeType": "ParameterList",
+              "parameters": [
+                {
+                  "constant": false,
+                  "id": 1141,
+                  "name": "owner",
+                  "nodeType": "VariableDeclaration",
+                  "scope": 1152,
+                  "src": "29225:13:1",
+                  "stateVariable": false,
+                  "storageLocation": "default",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_address",
+                    "typeString": "address"
+                  },
+                  "typeName": {
+                    "id": 1140,
+                    "name": "address",
+                    "nodeType": "ElementaryTypeName",
+                    "src": "29225:7:1",
+                    "stateMutability": "nonpayable",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_address",
+                      "typeString": "address"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                }
+              ],
+              "src": "29224:15:1"
+            },
+            "returnParameters": {
+              "id": 1146,
+              "nodeType": "ParameterList",
+              "parameters": [
+                {
+                  "constant": false,
+                  "id": 1145,
+                  "name": "",
+                  "nodeType": "VariableDeclaration",
+                  "scope": 1152,
+                  "src": "29263:17:1",
+                  "stateVariable": false,
+                  "storageLocation": "storage",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_array$_t_uint256_$dyn_storage_ptr",
+                    "typeString": "uint256[]"
+                  },
+                  "typeName": {
+                    "baseType": {
+                      "id": 1143,
+                      "name": "uint256",
+                      "nodeType": "ElementaryTypeName",
+                      "src": "29263:7:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_uint256",
+                        "typeString": "uint256"
+                      }
+                    },
+                    "id": 1144,
+                    "length": null,
+                    "nodeType": "ArrayTypeName",
+                    "src": "29263:9:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_array$_t_uint256_$dyn_storage_ptr",
+                      "typeString": "uint256[]"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                }
+              ],
+              "src": "29262:19:1"
+            },
+            "scope": 1302,
+            "src": "29201:124:1",
+            "stateMutability": "view",
+            "superFunction": null,
+            "visibility": "internal"
+          },
+          {
+            "body": {
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+              "nodeType": "Block",
+              "src": "29693:109:1",
+              "statements": [
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+                    "id": 1166,
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+                    "isLValue": false,
+                    "isPure": false,
+                    "lValueRequested": false,
+                    "leftHandSide": {
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+                      "baseExpression": {
+                        "argumentTypes": null,
+                        "id": 1159,
+                        "name": "_ownedTokensIndex",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 985,
+                        "src": "29703:17:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_mapping$_t_uint256_$_t_uint256_$",
+                          "typeString": "mapping(uint256 => uint256)"
+                        }
+                      },
+                      "id": 1161,
+                      "indexExpression": {
+                        "argumentTypes": null,
+                        "id": 1160,
+                        "name": "tokenId",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 1156,
+                        "src": "29721:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      },
+                      "isConstant": false,
+                      "isLValue": true,
+                      "isPure": false,
+                      "lValueRequested": true,
+                      "nodeType": "IndexAccess",
+                      "src": "29703:26:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_uint256",
+                        "typeString": "uint256"
+                      }
+                    },
+                    "nodeType": "Assignment",
+                    "operator": "=",
+                    "rightHandSide": {
+                      "argumentTypes": null,
+                      "expression": {
+                        "argumentTypes": null,
+                        "baseExpression": {
+                          "argumentTypes": null,
+                          "id": 1162,
+                          "name": "_ownedTokens",
+                          "nodeType": "Identifier",
+                          "overloadedDeclarations": [],
+                          "referencedDeclaration": 981,
+                          "src": "29732:12:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_mapping$_t_address_$_t_array$_t_uint256_$dyn_storage_$",
+                            "typeString": "mapping(address => uint256[] storage ref)"
+                          }
+                        },
+                        "id": 1164,
+                        "indexExpression": {
+                          "argumentTypes": null,
+                          "id": 1163,
+                          "name": "to",
+                          "nodeType": "Identifier",
+                          "overloadedDeclarations": [],
+                          "referencedDeclaration": 1154,
+                          "src": "29745:2:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_address",
+                            "typeString": "address"
+                          }
+                        },
+                        "isConstant": false,
+                        "isLValue": true,
+                        "isPure": false,
+                        "lValueRequested": false,
+                        "nodeType": "IndexAccess",
+                        "src": "29732:16:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_array$_t_uint256_$dyn_storage",
+                          "typeString": "uint256[] storage ref"
+                        }
+                      },
+                      "id": 1165,
+                      "isConstant": false,
+                      "isLValue": true,
+                      "isPure": false,
+                      "lValueRequested": false,
+                      "memberName": "length",
+                      "nodeType": "MemberAccess",
+                      "referencedDeclaration": null,
+                      "src": "29732:23:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_uint256",
+                        "typeString": "uint256"
+                      }
+                    },
+                    "src": "29703:52:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_uint256",
+                      "typeString": "uint256"
+                    }
+                  },
+                  "id": 1167,
+                  "nodeType": "ExpressionStatement",
+                  "src": "29703:52:1"
+                },
+                {
+                  "expression": {
+                    "argumentTypes": null,
+                    "arguments": [
+                      {
+                        "argumentTypes": null,
+                        "id": 1172,
+                        "name": "tokenId",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 1156,
+                        "src": "29787:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      }
+                    ],
+                    "expression": {
+                      "argumentTypes": [
+                        {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      ],
+                      "expression": {
+                        "argumentTypes": null,
+                        "baseExpression": {
+                          "argumentTypes": null,
+                          "id": 1168,
+                          "name": "_ownedTokens",
+                          "nodeType": "Identifier",
+                          "overloadedDeclarations": [],
+                          "referencedDeclaration": 981,
+                          "src": "29765:12:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_mapping$_t_address_$_t_array$_t_uint256_$dyn_storage_$",
+                            "typeString": "mapping(address => uint256[] storage ref)"
+                          }
+                        },
+                        "id": 1170,
+                        "indexExpression": {
+                          "argumentTypes": null,
+                          "id": 1169,
+                          "name": "to",
+                          "nodeType": "Identifier",
+                          "overloadedDeclarations": [],
+                          "referencedDeclaration": 1154,
+                          "src": "29778:2:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_address",
+                            "typeString": "address"
+                          }
+                        },
+                        "isConstant": false,
+                        "isLValue": true,
+                        "isPure": false,
+                        "lValueRequested": false,
+                        "nodeType": "IndexAccess",
+                        "src": "29765:16:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_array$_t_uint256_$dyn_storage",
+                          "typeString": "uint256[] storage ref"
+                        }
+                      },
+                      "id": 1171,
+                      "isConstant": false,
+                      "isLValue": false,
+                      "isPure": false,
+                      "lValueRequested": false,
+                      "memberName": "push",
+                      "nodeType": "MemberAccess",
+                      "referencedDeclaration": null,
+                      "src": "29765:21:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_function_arraypush_nonpayable$_t_uint256_$returns$_t_uint256_$",
+                        "typeString": "function (uint256) returns (uint256)"
+                      }
+                    },
+                    "id": 1173,
+                    "isConstant": false,
+                    "isLValue": false,
+                    "isPure": false,
+                    "kind": "functionCall",
+                    "lValueRequested": false,
+                    "names": [],
+                    "nodeType": "FunctionCall",
+                    "src": "29765:30:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_uint256",
+                      "typeString": "uint256"
+                    }
+                  },
+                  "id": 1174,
+                  "nodeType": "ExpressionStatement",
+                  "src": "29765:30:1"
+                }
+              ]
+            },
+            "documentation": "@dev Private function to add a token to this extension's ownership-tracking data structures.\n@param to address representing the new owner of the given token ID\n@param tokenId uint256 ID of the token to be added to the tokens list of the given address",
+            "id": 1176,
+            "implemented": true,
+            "kind": "function",
+            "modifiers": [],
+            "name": "_addTokenToOwnerEnumeration",
+            "nodeType": "FunctionDefinition",
+            "parameters": {
+              "id": 1157,
+              "nodeType": "ParameterList",
+              "parameters": [
+                {
+                  "constant": false,
+                  "id": 1154,
+                  "name": "to",
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+                            "overloadedDeclarations": [],
+                            "referencedDeclaration": 1222,
+                            "src": "31401:11:1",
+                            "typeDescriptions": {
+                              "typeIdentifier": "t_uint256",
+                              "typeString": "uint256"
+                            }
+                          },
+                          "src": "31368:44:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_uint256",
+                            "typeString": "uint256"
+                          }
+                        },
+                        "id": 1236,
+                        "nodeType": "ExpressionStatement",
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+                      },
+                      {
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+                          "id": 1241,
+                          "isConstant": false,
+                          "isLValue": false,
+                          "isPure": false,
+                          "lValueRequested": false,
+                          "leftHandSide": {
+                            "argumentTypes": null,
+                            "baseExpression": {
+                              "argumentTypes": null,
+                              "id": 1237,
+                              "name": "_ownedTokensIndex",
+                              "nodeType": "Identifier",
+                              "overloadedDeclarations": [],
+                              "referencedDeclaration": 985,
+                              "src": "31484:17:1",
+                              "typeDescriptions": {
+                                "typeIdentifier": "t_mapping$_t_uint256_$_t_uint256_$",
+                                "typeString": "mapping(uint256 => uint256)"
+                              }
+                            },
+                            "id": 1239,
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+                              "name": "lastTokenId",
+                              "nodeType": "Identifier",
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+                              "src": "31502:11:1",
+                              "typeDescriptions": {
+                                "typeIdentifier": "t_uint256",
+                                "typeString": "uint256"
+                              }
+                            },
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+                              "typeIdentifier": "t_uint256",
+                              "typeString": "uint256"
+                            }
+                          },
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+                          "operator": "=",
+                          "rightHandSide": {
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+                            "id": 1240,
+                            "name": "tokenIndex",
+                            "nodeType": "Identifier",
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+                            "referencedDeclaration": 1213,
+                            "src": "31517:10:1",
+                            "typeDescriptions": {
+                              "typeIdentifier": "t_uint256",
+                              "typeString": "uint256"
+                            }
+                          },
+                          "src": "31484:43:1",
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+                            "typeIdentifier": "t_uint256",
+                            "typeString": "uint256"
+                          }
+                        },
+                        "id": 1242,
+                        "nodeType": "ExpressionStatement",
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+                    ]
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+                          "name": "_ownedTokens",
+                          "nodeType": "Identifier",
+                          "overloadedDeclarations": [],
+                          "referencedDeclaration": 981,
+                          "src": "31658:12:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_mapping$_t_address_$_t_array$_t_uint256_$dyn_storage_$",
+                            "typeString": "mapping(address => uint256[] storage ref)"
+                          }
+                        },
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+                        "indexExpression": {
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+                          "overloadedDeclarations": [],
+                          "referencedDeclaration": 1197,
+                          "src": "31671:4:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_address",
+                            "typeString": "address"
+                          }
+                        },
+                        "isConstant": false,
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+                        "isPure": false,
+                        "lValueRequested": false,
+                        "nodeType": "IndexAccess",
+                        "src": "31658:18:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_array$_t_uint256_$dyn_storage",
+                          "typeString": "uint256[] storage ref"
+                        }
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+                      "isLValue": true,
+                      "isPure": false,
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+                      "src": "31658:25:1",
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+                      }
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+                    }
+                  },
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+                  "nodeType": "ExpressionStatement",
+                  "src": "31658:27:1"
+                }
+              ]
+            },
+            "documentation": "@dev Private function to remove a token from this extension's ownership-tracking data structures. Note that\nwhile the token is not assigned a new owner, the _ownedTokensIndex mapping is _not_ updated: this allows for\ngas optimizations e.g. when performing a transfer operation (avoiding double writes).\nThis has O(1) time complexity, but alters the order of the _ownedTokens array.\n@param from address representing the previous owner of the given token ID\n@param tokenId uint256 ID of the token to be removed from the tokens list of the given address",
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+            "name": "_removeTokenFromOwnerEnumeration",
+            "nodeType": "FunctionDefinition",
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+              "nodeType": "ParameterList",
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+                  "name": "from",
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+                  "src": "30815:12:1",
+                  "stateVariable": false,
+                  "storageLocation": "default",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_address",
+                    "typeString": "address"
+                  },
+                  "typeName": {
+                    "id": 1196,
+                    "name": "address",
+                    "nodeType": "ElementaryTypeName",
+                    "src": "30815:7:1",
+                    "stateMutability": "nonpayable",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_address",
+                      "typeString": "address"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                },
+                {
+                  "constant": false,
+                  "id": 1199,
+                  "name": "tokenId",
+                  "nodeType": "VariableDeclaration",
+                  "scope": 1252,
+                  "src": "30829:15:1",
+                  "stateVariable": false,
+                  "storageLocation": "default",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_uint256",
+                    "typeString": "uint256"
+                  },
+                  "typeName": {
+                    "id": 1198,
+                    "name": "uint256",
+                    "nodeType": "ElementaryTypeName",
+                    "src": "30829:7:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_uint256",
+                      "typeString": "uint256"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                }
+              ],
+              "src": "30814:31:1"
+            },
+            "returnParameters": {
+              "id": 1201,
+              "nodeType": "ParameterList",
+              "parameters": [],
+              "src": "30854:0:1"
+            },
+            "scope": 1302,
+            "src": "30773:1128:1",
+            "stateMutability": "nonpayable",
+            "superFunction": null,
+            "visibility": "private"
+          },
+          {
+            "body": {
+              "id": 1300,
+              "nodeType": "Block",
+              "src": "32260:993:1",
+              "statements": [
+                {
+                  "assignments": [
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+                  ],
+                  "declarations": [
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+                      "constant": false,
+                      "id": 1258,
+                      "name": "lastTokenIndex",
+                      "nodeType": "VariableDeclaration",
+                      "scope": 1300,
+                      "src": "32438:22:1",
+                      "stateVariable": false,
+                      "storageLocation": "default",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_uint256",
+                        "typeString": "uint256"
+                      },
+                      "typeName": {
+                        "id": 1257,
+                        "name": "uint256",
+                        "nodeType": "ElementaryTypeName",
+                        "src": "32438:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      },
+                      "value": null,
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+                        "hexValue": "31",
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+                        "isConstant": false,
+                        "isLValue": false,
+                        "isPure": true,
+                        "kind": "number",
+                        "lValueRequested": false,
+                        "nodeType": "Literal",
+                        "src": "32485:1:1",
+                        "subdenomination": null,
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_rational_1_by_1",
+                          "typeString": "int_const 1"
+                        },
+                        "value": "1"
+                      }
+                    ],
+                    "expression": {
+                      "argumentTypes": [
+                        {
+                          "typeIdentifier": "t_rational_1_by_1",
+                          "typeString": "int_const 1"
+                        }
+                      ],
+                      "expression": {
+                        "argumentTypes": null,
+                        "expression": {
+                          "argumentTypes": null,
+                          "id": 1259,
+                          "name": "_allTokens",
+                          "nodeType": "Identifier",
+                          "overloadedDeclarations": [],
+                          "referencedDeclaration": 988,
+                          "src": "32463:10:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_array$_t_uint256_$dyn_storage",
+                            "typeString": "uint256[] storage ref"
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+                      "memberName": "sub",
+                      "nodeType": "MemberAccess",
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+                      "src": "32463:21:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_function_internal_pure$_t_uint256_$_t_uint256_$returns$_t_uint256_$bound_to$_t_uint256_$",
+                        "typeString": "function (uint256,uint256) pure returns (uint256)"
+                      }
+                    },
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+                    "isConstant": false,
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+                    "isPure": false,
+                    "kind": "functionCall",
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+                    "names": [],
+                    "nodeType": "FunctionCall",
+                    "src": "32463:24:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_uint256",
+                      "typeString": "uint256"
+                    }
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+                  "src": "32438:49:1"
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+                      },
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+                        "name": "uint256",
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+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
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+                      "src": "32518:15:1",
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+                        "typeIdentifier": "t_mapping$_t_uint256_$_t_uint256_$",
+                        "typeString": "mapping(uint256 => uint256)"
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+                      "src": "32534:7:1",
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+                    "nodeType": "IndexAccess",
+                    "src": "32518:24:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_uint256",
+                      "typeString": "uint256"
+                    }
+                  },
+                  "nodeType": "VariableDeclarationStatement",
+                  "src": "32497:45:1"
+                },
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+                  ],
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+                      "name": "lastTokenId",
+                      "nodeType": "VariableDeclaration",
+                      "scope": 1300,
+                      "src": "32864:19:1",
+                      "stateVariable": false,
+                      "storageLocation": "default",
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+                        "typeIdentifier": "t_uint256",
+                        "typeString": "uint256"
+                      },
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+                        "name": "uint256",
+                        "nodeType": "ElementaryTypeName",
+                        "src": "32864:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
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+                        "typeIdentifier": "t_uint256",
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+                          "typeIdentifier": "t_array$_t_uint256_$dyn_storage",
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+                        "typeDescriptions": {
+                          "typeIdentifier": "t_mapping$_t_uint256_$_t_uint256_$",
+                          "typeString": "mapping(uint256 => uint256)"
+                        }
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+                          "typeString": "address"
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+                              "typeString": "bytes memory"
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+                      "typeString": "bytes"
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+            "stateMutability": "nonpayable",
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+              "nodeType": "Block",
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+              "statements": [
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+                      "name": "owner",
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+                      "scope": 683,
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+                      "stateVariable": false,
+                      "storageLocation": "default",
+                      "typeDescriptions": {
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+                        "typeString": "address"
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+                        "name": "address",
+                        "nodeType": "ElementaryTypeName",
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+                        "stateMutability": "nonpayable",
+                        "typeDescriptions": {
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+                      "src": "19778:11:1",
+                      "typeDescriptions": {
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+                        "typeString": "mapping(uint256 => address)"
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+                      "src": "19790:7:1",
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+                          "hexValue": "30",
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+                          "nodeType": "Literal",
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+                          "typeDescriptions": {
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+                            "typeString": "int_const 0"
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+                          "value": "0"
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+                        "isLValue": false,
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+                        "lValueRequested": false,
+                        "nodeType": "ElementaryTypeNameExpression",
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+                        "typeDescriptions": {
+                          "typeIdentifier": "t_type$_t_address_$",
+                          "typeString": "type(address)"
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+                      "isPure": true,
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+                      "typeDescriptions": {
+                        "typeIdentifier": "t_address_payable",
+                        "typeString": "address payable"
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+            "kind": "function",
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+                      "typeString": "uint256"
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+                  "visibility": "internal"
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+              "src": "19705:17:1"
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+                  "src": "19746:4:1",
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+                  "storageLocation": "default",
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+            "stateMutability": "view",
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+            "visibility": "internal"
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+                    "arguments": [
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+                        "arguments": [
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+                            "id": 695,
+                            "name": "tokenId",
+                            "nodeType": "Identifier",
+                            "overloadedDeclarations": [],
+                            "referencedDeclaration": 688,
+                            "src": "20319:7:1",
+                            "typeDescriptions": {
+                              "typeIdentifier": "t_uint256",
+                              "typeString": "uint256"
+                            }
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+                        "expression": {
+                          "argumentTypes": [
+                            {
+                              "typeIdentifier": "t_uint256",
+                              "typeString": "uint256"
+                            }
+                          ],
+                          "id": 694,
+                          "name": "_exists",
+                          "nodeType": "Identifier",
+                          "overloadedDeclarations": [],
+                          "referencedDeclaration": 684,
+                          "src": "20311:7:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_function_internal_view$_t_uint256_$returns$_t_bool_$",
+                            "typeString": "function (uint256) view returns (bool)"
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+                              "typeString": "address"
+                            }
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+                          "name": "IERC721Receiver",
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+                          "referencedDeclaration": 139,
+                          "src": "23593:15:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_type$_t_contract$_IERC721Receiver_$139_$",
+                            "typeString": "type(contract IERC721Receiver)"
+                          }
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+                        "kind": "typeConversion",
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+                      }
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+                    "nodeType": "FunctionCall",
+                    "src": "23593:70:1",
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+                      "typeString": "bytes4"
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+                            "typeString": "bytes4"
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+                            "typeIdentifier": "t_bytes4",
+                            "typeString": "bytes4"
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+                    "typeDescriptions": {
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+                  "visibility": "internal"
+                }
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+                        "src": "23940:15:1",
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+                          "typeIdentifier": "t_mapping$_t_uint256_$_t_address_$",
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+                        "name": "tokenId",
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+                        "src": "23956:7:1",
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+                          "typeDescriptions": {
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+                            "typeString": "int_const 0"
+                          },
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+                      ],
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+                        "typeString": "address payable"
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+                              "name": "_tokenApprovals",
+                              "nodeType": "Identifier",
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+                              "referencedDeclaration": 411,
+                              "src": "23994:15:1",
+                              "typeDescriptions": {
+                                "typeIdentifier": "t_mapping$_t_uint256_$_t_address_$",
+                                "typeString": "mapping(uint256 => address)"
+                              }
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+                              "name": "tokenId",
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+                              "referencedDeclaration": 922,
+                              "src": "24010:7:1",
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+                              "typeIdentifier": "t_address",
+                              "typeString": "address"
+                            }
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+                                "hexValue": "30",
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+                                "kind": "number",
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+                                "nodeType": "Literal",
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+                                  "typeIdentifier": "t_rational_0_by_1",
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+                              "lValueRequested": false,
+                              "nodeType": "ElementaryTypeNameExpression",
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+                            "names": [],
+                            "nodeType": "FunctionCall",
+                            "src": "24021:10:1",
+                            "typeDescriptions": {
+                              "typeIdentifier": "t_address_payable",
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+                      }
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+                  "storageLocation": "default",
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+                    "typeString": "address"
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+                    "name": "address",
+                    "nodeType": "ElementaryTypeName",
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+                      "typeString": "address"
+                    }
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+                  "visibility": "internal"
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+            "stateMutability": "view",
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+                      "name": "_allTokens",
+                      "nodeType": "Identifier",
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+                      "src": "26732:10:1",
+                      "typeDescriptions": {
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+                    "memberName": "length",
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+                    "src": "26732:17:1",
+                    "typeDescriptions": {
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+                  "id": 1035,
+                  "nodeType": "Return",
+                  "src": "26725:24:1"
+                }
+              ]
+            },
+            "documentation": "@dev Gets the total amount of tokens stored by the contract.\n@return uint256 representing the total amount of tokens",
+            "id": 1037,
+            "implemented": true,
+            "kind": "function",
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+                  "storageLocation": "default",
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+                    "typeString": "uint256"
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+                      "typeString": "uint256"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                }
+              ],
+              "src": "26705:9:1"
+            },
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+            "src": "26662:94:1",
+            "stateMutability": "view",
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+            "visibility": "public"
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+                        "commonType": {
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+                          "typeString": "uint256"
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+                          "id": 1045,
+                          "name": "index",
+                          "nodeType": "Identifier",
+                          "overloadedDeclarations": [],
+                          "referencedDeclaration": 1039,
+                          "src": "27179:5:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_uint256",
+                            "typeString": "uint256"
+                          }
+                        },
+                        "nodeType": "BinaryOperation",
+                        "operator": "<",
+                        "rightExpression": {
+                          "argumentTypes": null,
+                          "arguments": [],
+                          "expression": {
+                            "argumentTypes": [],
+                            "id": 1046,
+                            "name": "totalSupply",
+                            "nodeType": "Identifier",
+                            "overloadedDeclarations": [
+                              1037
+                            ],
+                            "referencedDeclaration": 1037,
+                            "src": "27187:11:1",
+                            "typeDescriptions": {
+                              "typeIdentifier": "t_function_internal_view$__$returns$_t_uint256_$",
+                              "typeString": "function () view returns (uint256)"
+                            }
+                          },
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+                          "isConstant": false,
+                          "isLValue": false,
+                          "isPure": false,
+                          "kind": "functionCall",
+                          "lValueRequested": false,
+                          "names": [],
+                          "nodeType": "FunctionCall",
+                          "src": "27187:13:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_uint256",
+                            "typeString": "uint256"
+                          }
+                        },
+                        "src": "27179:21:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_bool",
+                          "typeString": "bool"
+                        }
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+                        "isPure": true,
+                        "kind": "string",
+                        "lValueRequested": false,
+                        "nodeType": "Literal",
+                        "src": "27202:46:1",
+                        "subdenomination": null,
+                        "typeDescriptions": {
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+                          "typeString": "literal_string \"ERC721Enumerable: global index out of bounds\""
+                        },
+                        "value": "ERC721Enumerable: global index out of bounds"
+                      }
+                    ],
+                    "expression": {
+                      "argumentTypes": [
+                        {
+                          "typeIdentifier": "t_bool",
+                          "typeString": "bool"
+                        },
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+                        1544
+                      ],
+                      "referencedDeclaration": 1544,
+                      "src": "27171:7:1",
+                      "typeDescriptions": {
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+                        "typeString": "function (bool,string memory) pure"
+                      }
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+                    "isConstant": false,
+                    "isLValue": false,
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+                    "kind": "functionCall",
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+                    }
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+                },
+                {
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+                    "baseExpression": {
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+                      "id": 1052,
+                      "name": "_allTokens",
+                      "nodeType": "Identifier",
+                      "overloadedDeclarations": [],
+                      "referencedDeclaration": 988,
+                      "src": "27266:10:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_array$_t_uint256_$dyn_storage",
+                        "typeString": "uint256[] storage ref"
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+                    "id": 1054,
+                    "indexExpression": {
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+                      "id": 1053,
+                      "name": "index",
+                      "nodeType": "Identifier",
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+                      "referencedDeclaration": 1039,
+                      "src": "27277:5:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_uint256",
+                        "typeString": "uint256"
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+                }
+              ]
+            },
+            "documentation": "@dev Gets the token ID at a given index of all the tokens in this contract\nReverts if the index is greater or equal to the total number of tokens.\n@param index uint256 representing the index to be accessed of the tokens list\n@return uint256 token ID at the given index of the tokens list",
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+            "implemented": true,
+            "kind": "function",
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+                  "stateVariable": false,
+                  "storageLocation": "default",
+                  "typeDescriptions": {
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+                    "typeString": "uint256"
+                  },
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+                    "name": "uint256",
+                    "nodeType": "ElementaryTypeName",
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+                    "typeDescriptions": {
+                      "typeIdentifier": "t_uint256",
+                      "typeString": "uint256"
+                    }
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+                  "value": null,
+                  "visibility": "internal"
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+                  "nodeType": "VariableDeclaration",
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+                  "src": "27152:7:1",
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+                  "storageLocation": "default",
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+            "stateMutability": "view",
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+                        "referencedDeclaration": 1059,
+                        "src": "27770:4:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        }
+                      },
+                      {
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+                        "id": 1070,
+                        "name": "to",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 1061,
+                        "src": "27776:2:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        }
+                      },
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+                        "id": 1071,
+                        "name": "tokenId",
+                        "nodeType": "Identifier",
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+                        "referencedDeclaration": 1063,
+                        "src": "27780:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      }
+                    ],
+                    "expression": {
+                      "argumentTypes": [
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+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        },
+                        {
+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        },
+                        {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
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+                        "name": "super",
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+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 1572,
+                        "src": "27750:5:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_super$_ERC721Enumerable_$1302",
+                          "typeString": "contract super ERC721Enumerable"
+                        }
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+                      "nodeType": "MemberAccess",
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+                      "src": "27750:19:1",
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+                        "name": "from",
+                        "nodeType": "Identifier",
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+                        "referencedDeclaration": 1059,
+                        "src": "27832:4:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        }
+                      },
+                      {
+                        "argumentTypes": null,
+                        "id": 1076,
+                        "name": "tokenId",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 1063,
+                        "src": "27838:7:1",
+                        "typeDescriptions": {
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+                          "typeString": "uint256"
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+                          "typeString": "address"
+                        },
+                        {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      ],
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+                      "nodeType": "Identifier",
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+                      "src": "27799:32:1",
+                      "typeDescriptions": {
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+                      "typeString": "tuple()"
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+                        "id": 1080,
+                        "name": "to",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 1061,
+                        "src": "27885:2:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        }
+                      },
+                      {
+                        "argumentTypes": null,
+                        "id": 1081,
+                        "name": "tokenId",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 1063,
+                        "src": "27889:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
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+                      "argumentTypes": [
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+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        },
+                        {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      ],
+                      "id": 1079,
+                      "name": "_addTokenToOwnerEnumeration",
+                      "nodeType": "Identifier",
+                      "overloadedDeclarations": [],
+                      "referencedDeclaration": 1176,
+                      "src": "27857:27:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_function_internal_nonpayable$_t_address_$_t_uint256_$returns$__$",
+                        "typeString": "function (address,uint256)"
+                      }
+                    },
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+                    "isConstant": false,
+                    "isLValue": false,
+                    "isPure": false,
+                    "kind": "functionCall",
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+                }
+              ]
+            },
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+            "kind": "function",
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+                  "name": "from",
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+                  "src": "27688:12:1",
+                  "stateVariable": false,
+                  "storageLocation": "default",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_address",
+                    "typeString": "address"
+                  },
+                  "typeName": {
+                    "id": 1058,
+                    "name": "address",
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+                        "src": "28236:2:1",
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+                        "src": "28240:7:1",
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+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
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+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        },
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+                          "typeIdentifier": "t_uint256",
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+                        "src": "28224:5:1",
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+                          "typeString": "contract super ERC721Enumerable"
+                        }
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+                        "src": "28287:2:1",
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+                          "typeString": "address"
+                        }
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+                        "name": "tokenId",
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+                        "src": "28291:7:1",
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+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
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+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        },
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+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
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+                      "typeString": "tuple()"
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+                        "name": "tokenId",
+                        "nodeType": "Identifier",
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+                        "src": "28342:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
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+                      "argumentTypes": [
+                        {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
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+                      "nodeType": "Identifier",
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+                      "src": "28310:31:1",
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+                        "typeString": "function (uint256)"
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+                  "id": 1107,
+                  "nodeType": "ExpressionStatement",
+                  "src": "28310:40:1"
+                }
+              ]
+            },
+            "documentation": "@dev Internal function to mint a new token.\nReverts if the given token ID already exists.\n@param to address the beneficiary that will own the minted token\n@param tokenId uint256 ID of the token to be minted",
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+                    "name": "address",
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+                    "stateMutability": "nonpayable",
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+                      "typeString": "address"
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+                },
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+                  "src": "28188:15:1",
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+                  "storageLocation": "default",
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+                        "name": "owner",
+                        "nodeType": "Identifier",
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+                        "referencedDeclaration": 1111,
+                        "src": "28710:5:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        }
+                      },
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+                        "id": 1120,
+                        "name": "tokenId",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 1113,
+                        "src": "28717:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      }
+                    ],
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+                      "argumentTypes": [
+                        {
+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        },
+                        {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
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+                        "id": 1116,
+                        "name": "super",
+                        "nodeType": "Identifier",
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+                        "referencedDeclaration": 1572,
+                        "src": "28698:5:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_super$_ERC721Enumerable_$1302",
+                          "typeString": "contract super ERC721Enumerable"
+                        }
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+                      "isLValue": false,
+                      "isPure": false,
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+                      "memberName": "_burn",
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+                      "src": "28698:11:1",
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+                        "name": "owner",
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+                        "src": "28769:5:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        }
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+                        "id": 1125,
+                        "name": "tokenId",
+                        "nodeType": "Identifier",
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+                        "referencedDeclaration": 1113,
+                        "src": "28776:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      }
+                    ],
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+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        },
+                        {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
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+                      "id": 1123,
+                      "name": "_removeTokenFromOwnerEnumeration",
+                      "nodeType": "Identifier",
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+                      "referencedDeclaration": 1252,
+                      "src": "28736:32:1",
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+                    "kind": "functionCall",
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+                        "id": 1128,
+                        "name": "_ownedTokensIndex",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 985,
+                        "src": "28903:17:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_mapping$_t_uint256_$_t_uint256_$",
+                          "typeString": "mapping(uint256 => uint256)"
+                        }
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+                      "id": 1130,
+                      "indexExpression": {
+                        "argumentTypes": null,
+                        "id": 1129,
+                        "name": "tokenId",
+                        "nodeType": "Identifier",
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+                        "referencedDeclaration": 1113,
+                        "src": "28921:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
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+                      "nodeType": "IndexAccess",
+                      "src": "28903:26:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_uint256",
+                        "typeString": "uint256"
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+                    "nodeType": "Assignment",
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+                      "hexValue": "30",
+                      "id": 1131,
+                      "isConstant": false,
+                      "isLValue": false,
+                      "isPure": true,
+                      "kind": "number",
+                      "lValueRequested": false,
+                      "nodeType": "Literal",
+                      "src": "28932:1:1",
+                      "subdenomination": null,
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_rational_0_by_1",
+                        "typeString": "int_const 0"
+                      },
+                      "value": "0"
+                    },
+                    "src": "28903:30:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_uint256",
+                      "typeString": "uint256"
+                    }
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+                  "id": 1133,
+                  "nodeType": "ExpressionStatement",
+                  "src": "28903:30:1"
+                },
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+                        "id": 1135,
+                        "name": "tokenId",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 1113,
+                        "src": "28981:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      }
+                    ],
+                    "expression": {
+                      "argumentTypes": [
+                        {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
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+                      "name": "_removeTokenFromAllTokensEnumeration",
+                      "nodeType": "Identifier",
+                      "overloadedDeclarations": [],
+                      "referencedDeclaration": 1301,
+                      "src": "28944:36:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_function_internal_nonpayable$_t_uint256_$returns$__$",
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+                      "typeString": "tuple()"
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+                  "id": 1137,
+                  "nodeType": "ExpressionStatement",
+                  "src": "28944:45:1"
+                }
+              ]
+            },
+            "documentation": "@dev Internal function to burn a specific token.\nReverts if the token does not exist.\nDeprecated, use _burn(uint256) instead.\n@param owner owner of the token to burn\n@param tokenId uint256 ID of the token being burned",
+            "id": 1139,
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+            "name": "_burn",
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+                  "id": 1111,
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+                  "scope": 1139,
+                  "src": "28647:13:1",
+                  "stateVariable": false,
+                  "storageLocation": "default",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_address",
+                    "typeString": "address"
+                  },
+                  "typeName": {
+                    "id": 1110,
+                    "name": "address",
+                    "nodeType": "ElementaryTypeName",
+                    "src": "28647:7:1",
+                    "stateMutability": "nonpayable",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_address",
+                      "typeString": "address"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                },
+                {
+                  "constant": false,
+                  "id": 1113,
+                  "name": "tokenId",
+                  "nodeType": "VariableDeclaration",
+                  "scope": 1139,
+                  "src": "28662:15:1",
+                  "stateVariable": false,
+                  "storageLocation": "default",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_uint256",
+                    "typeString": "uint256"
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+                  "typeName": {
+                    "id": 1112,
+                    "name": "uint256",
+                    "nodeType": "ElementaryTypeName",
+                    "src": "28662:7:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_uint256",
+                      "typeString": "uint256"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                }
+              ],
+              "src": "28646:32:1"
+            },
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+              "src": "28688:0:1"
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+            "scope": 1302,
+            "src": "28632:364:1",
+            "stateMutability": "nonpayable",
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+            "visibility": "internal"
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+              "nodeType": "Block",
+              "src": "29282:43:1",
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+                    "baseExpression": {
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+                      "id": 1147,
+                      "name": "_ownedTokens",
+                      "nodeType": "Identifier",
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+                      "referencedDeclaration": 981,
+                      "src": "29299:12:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_mapping$_t_address_$_t_array$_t_uint256_$dyn_storage_$",
+                        "typeString": "mapping(address => uint256[] storage ref)"
+                      }
+                    },
+                    "id": 1149,
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+                      "id": 1148,
+                      "name": "owner",
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+                      "src": "31060:29:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_function_internal_pure$_t_uint256_$_t_uint256_$returns$_t_uint256_$bound_to$_t_uint256_$",
+                        "typeString": "function (uint256,uint256) pure returns (uint256)"
+                      }
+                    },
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+                    "isLValue": false,
+                    "isPure": false,
+                    "kind": "functionCall",
+                    "lValueRequested": false,
+                    "names": [],
+                    "nodeType": "FunctionCall",
+                    "src": "31060:32:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_uint256",
+                      "typeString": "uint256"
+                    }
+                  },
+                  "nodeType": "VariableDeclarationStatement",
+                  "src": "31035:57:1"
+                },
+                {
+                  "assignments": [
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+                  ],
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+                      "name": "tokenIndex",
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+                      "src": "31102:18:1",
+                      "stateVariable": false,
+                      "storageLocation": "default",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_uint256",
+                        "typeString": "uint256"
+                      },
+                      "typeName": {
+                        "id": 1212,
+                        "name": "uint256",
+                        "nodeType": "ElementaryTypeName",
+                        "src": "31102:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      },
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+                    }
+                  ],
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+                      "src": "31123:17:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_mapping$_t_uint256_$_t_uint256_$",
+                        "typeString": "mapping(uint256 => uint256)"
+                      }
+                    },
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+                      "src": "31141:7:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_uint256",
+                        "typeString": "uint256"
+                      }
+                    },
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+                    "nodeType": "IndexAccess",
+                    "src": "31123:26:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_uint256",
+                      "typeString": "uint256"
+                    }
+                  },
+                  "nodeType": "VariableDeclarationStatement",
+                  "src": "31102:47:1"
+                },
+                {
+                  "condition": {
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+                    "commonType": {
+                      "typeIdentifier": "t_uint256",
+                      "typeString": "uint256"
+                    },
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+                      "src": "31253:10:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_uint256",
+                        "typeString": "uint256"
+                      }
+                    },
+                    "nodeType": "BinaryOperation",
+                    "operator": "!=",
+                    "rightExpression": {
+                      "argumentTypes": null,
+                      "id": 1219,
+                      "name": "lastTokenIndex",
+                      "nodeType": "Identifier",
+                      "overloadedDeclarations": [],
+                      "referencedDeclaration": 1203,
+                      "src": "31267:14:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_uint256",
+                        "typeString": "uint256"
+                      }
+                    },
+                    "src": "31253:28:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_bool",
+                      "typeString": "bool"
+                    }
+                  },
+                  "falseBody": null,
+                  "id": 1244,
+                  "nodeType": "IfStatement",
+                  "src": "31249:323:1",
+                  "trueBody": {
+                    "id": 1243,
+                    "nodeType": "Block",
+                    "src": "31283:289:1",
+                    "statements": [
+                      {
+                        "assignments": [
+                          1222
+                        ],
+                        "declarations": [
+                          {
+                            "constant": false,
+                            "id": 1222,
+                            "name": "lastTokenId",
+                            "nodeType": "VariableDeclaration",
+                            "scope": 1243,
+                            "src": "31297:19:1",
+                            "stateVariable": false,
+                            "storageLocation": "default",
+                            "typeDescriptions": {
+                              "typeIdentifier": "t_uint256",
+                              "typeString": "uint256"
+                            },
+                            "typeName": {
+                              "id": 1221,
+                              "name": "uint256",
+                              "nodeType": "ElementaryTypeName",
+                              "src": "31297:7:1",
+                              "typeDescriptions": {
+                                "typeIdentifier": "t_uint256",
+                                "typeString": "uint256"
+                              }
+                            },
+                            "value": null,
+                            "visibility": "internal"
+                          }
+                        ],
+                        "id": 1228,
+                        "initialValue": {
+                          "argumentTypes": null,
+                          "baseExpression": {
+                            "argumentTypes": null,
+                            "baseExpression": {
+                              "argumentTypes": null,
+                              "id": 1223,
+                              "name": "_ownedTokens",
+                              "nodeType": "Identifier",
+                              "overloadedDeclarations": [],
+                              "referencedDeclaration": 981,
+                              "src": "31319:12:1",
+                              "typeDescriptions": {
+                                "typeIdentifier": "t_mapping$_t_address_$_t_array$_t_uint256_$dyn_storage_$",
+                                "typeString": "mapping(address => uint256[] storage ref)"
+                              }
+                            },
+                            "id": 1225,
+                            "indexExpression": {
+                              "argumentTypes": null,
+                              "id": 1224,
+                              "name": "from",
+                              "nodeType": "Identifier",
+                              "overloadedDeclarations": [],
+                              "referencedDeclaration": 1197,
+                              "src": "31332:4:1",
+                              "typeDescriptions": {
+                                "typeIdentifier": "t_address",
+                                "typeString": "address"
+                              }
+                            },
+                            "isConstant": false,
+                            "isLValue": true,
+                            "isPure": false,
+                            "lValueRequested": false,
+                            "nodeType": "IndexAccess",
+                            "src": "31319:18:1",
+                            "typeDescriptions": {
+                              "typeIdentifier": "t_array$_t_uint256_$dyn_storage",
+                              "typeString": "uint256[] storage ref"
+                            }
+                          },
+                          "id": 1227,
+                          "indexExpression": {
+                            "argumentTypes": null,
+                            "id": 1226,
+                            "name": "lastTokenIndex",
+                            "nodeType": "Identifier",
+                            "overloadedDeclarations": [],
+                            "referencedDeclaration": 1203,
+                            "src": "31338:14:1",
+                            "typeDescriptions": {
+                              "typeIdentifier": "t_uint256",
+                              "typeString": "uint256"
+                            }
+                          },
+                          "isConstant": false,
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+                          "isPure": false,
+                          "lValueRequested": false,
+                          "nodeType": "IndexAccess",
+                          "src": "31319:34:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_uint256",
+                            "typeString": "uint256"
+                          }
+                        },
+                        "nodeType": "VariableDeclarationStatement",
+                        "src": "31297:56:1"
+                      },
+                      {
+                        "expression": {
+                          "argumentTypes": null,
+                          "id": 1235,
+                          "isConstant": false,
+                          "isLValue": false,
+                          "isPure": false,
+                          "lValueRequested": false,
+                          "leftHandSide": {
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+                            "baseExpression": {
+                              "argumentTypes": null,
+                              "baseExpression": {
+                                "argumentTypes": null,
+                                "id": 1229,
+                                "name": "_ownedTokens",
+                                "nodeType": "Identifier",
+                                "overloadedDeclarations": [],
+                                "referencedDeclaration": 981,
+                                "src": "31368:12:1",
+                                "typeDescriptions": {
+                                  "typeIdentifier": "t_mapping$_t_address_$_t_array$_t_uint256_$dyn_storage_$",
+                                  "typeString": "mapping(address => uint256[] storage ref)"
+                                }
+                              },
+                              "id": 1232,
+                              "indexExpression": {
+                                "argumentTypes": null,
+                                "id": 1230,
+                                "name": "from",
+                                "nodeType": "Identifier",
+                                "overloadedDeclarations": [],
+                                "referencedDeclaration": 1197,
+                                "src": "31381:4:1",
+                                "typeDescriptions": {
+                                  "typeIdentifier": "t_address",
+                                  "typeString": "address"
+                                }
+                              },
+                              "isConstant": false,
+                              "isLValue": true,
+                              "isPure": false,
+                              "lValueRequested": false,
+                              "nodeType": "IndexAccess",
+                              "src": "31368:18:1",
+                              "typeDescriptions": {
+                                "typeIdentifier": "t_array$_t_uint256_$dyn_storage",
+                                "typeString": "uint256[] storage ref"
+                              }
+                            },
+                            "id": 1233,
+                            "indexExpression": {
+                              "argumentTypes": null,
+                              "id": 1231,
+                              "name": "tokenIndex",
+                              "nodeType": "Identifier",
+                              "overloadedDeclarations": [],
+                              "referencedDeclaration": 1213,
+                              "src": "31387:10:1",
+                              "typeDescriptions": {
+                                "typeIdentifier": "t_uint256",
+                                "typeString": "uint256"
+                              }
+                            },
+                            "isConstant": false,
+                            "isLValue": true,
+                            "isPure": false,
+                            "lValueRequested": true,
+                            "nodeType": "IndexAccess",
+                            "src": "31368:30:1",
+                            "typeDescriptions": {
+                              "typeIdentifier": "t_uint256",
+                              "typeString": "uint256"
+                            }
+                          },
+                          "nodeType": "Assignment",
+                          "operator": "=",
+                          "rightHandSide": {
+                            "argumentTypes": null,
+                            "id": 1234,
+                            "name": "lastTokenId",
+                            "nodeType": "Identifier",
+                            "overloadedDeclarations": [],
+                            "referencedDeclaration": 1222,
+                            "src": "31401:11:1",
+                            "typeDescriptions": {
+                              "typeIdentifier": "t_uint256",
+                              "typeString": "uint256"
+                            }
+                          },
+                          "src": "31368:44:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_uint256",
+                            "typeString": "uint256"
+                          }
+                        },
+                        "id": 1236,
+                        "nodeType": "ExpressionStatement",
+                        "src": "31368:44:1"
+                      },
+                      {
+                        "expression": {
+                          "argumentTypes": null,
+                          "id": 1241,
+                          "isConstant": false,
+                          "isLValue": false,
+                          "isPure": false,
+                          "lValueRequested": false,
+                          "leftHandSide": {
+                            "argumentTypes": null,
+                            "baseExpression": {
+                              "argumentTypes": null,
+                              "id": 1237,
+                              "name": "_ownedTokensIndex",
+                              "nodeType": "Identifier",
+                              "overloadedDeclarations": [],
+                              "referencedDeclaration": 985,
+                              "src": "31484:17:1",
+                              "typeDescriptions": {
+                                "typeIdentifier": "t_mapping$_t_uint256_$_t_uint256_$",
+                                "typeString": "mapping(uint256 => uint256)"
+                              }
+                            },
+                            "id": 1239,
+                            "indexExpression": {
+                              "argumentTypes": null,
+                              "id": 1238,
+                              "name": "lastTokenId",
+                              "nodeType": "Identifier",
+                              "overloadedDeclarations": [],
+                              "referencedDeclaration": 1222,
+                              "src": "31502:11:1",
+                              "typeDescriptions": {
+                                "typeIdentifier": "t_uint256",
+                                "typeString": "uint256"
+                              }
+                            },
+                            "isConstant": false,
+                            "isLValue": true,
+                            "isPure": false,
+                            "lValueRequested": true,
+                            "nodeType": "IndexAccess",
+                            "src": "31484:30:1",
+                            "typeDescriptions": {
+                              "typeIdentifier": "t_uint256",
+                              "typeString": "uint256"
+                            }
+                          },
+                          "nodeType": "Assignment",
+                          "operator": "=",
+                          "rightHandSide": {
+                            "argumentTypes": null,
+                            "id": 1240,
+                            "name": "tokenIndex",
+                            "nodeType": "Identifier",
+                            "overloadedDeclarations": [],
+                            "referencedDeclaration": 1213,
+                            "src": "31517:10:1",
+                            "typeDescriptions": {
+                              "typeIdentifier": "t_uint256",
+                              "typeString": "uint256"
+                            }
+                          },
+                          "src": "31484:43:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_uint256",
+                            "typeString": "uint256"
+                          }
+                        },
+                        "id": 1242,
+                        "nodeType": "ExpressionStatement",
+                        "src": "31484:43:1"
+                      }
+                    ]
+                  }
+                },
+                {
+                  "expression": {
+                    "argumentTypes": null,
+                    "id": 1249,
+                    "isConstant": false,
+                    "isLValue": false,
+                    "isPure": false,
+                    "lValueRequested": false,
+                    "nodeType": "UnaryOperation",
+                    "operator": "--",
+                    "prefix": false,
+                    "src": "31658:27:1",
+                    "subExpression": {
+                      "argumentTypes": null,
+                      "expression": {
+                        "argumentTypes": null,
+                        "baseExpression": {
+                          "argumentTypes": null,
+                          "id": 1245,
+                          "name": "_ownedTokens",
+                          "nodeType": "Identifier",
+                          "overloadedDeclarations": [],
+                          "referencedDeclaration": 981,
+                          "src": "31658:12:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_mapping$_t_address_$_t_array$_t_uint256_$dyn_storage_$",
+                            "typeString": "mapping(address => uint256[] storage ref)"
+                          }
+                        },
+                        "id": 1247,
+                        "indexExpression": {
+                          "argumentTypes": null,
+                          "id": 1246,
+                          "name": "from",
+                          "nodeType": "Identifier",
+                          "overloadedDeclarations": [],
+                          "referencedDeclaration": 1197,
+                          "src": "31671:4:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_address",
+                            "typeString": "address"
+                          }
+                        },
+                        "isConstant": false,
+                        "isLValue": true,
+                        "isPure": false,
+                        "lValueRequested": false,
+                        "nodeType": "IndexAccess",
+                        "src": "31658:18:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_array$_t_uint256_$dyn_storage",
+                          "typeString": "uint256[] storage ref"
+                        }
+                      },
+                      "id": 1248,
+                      "isConstant": false,
+                      "isLValue": true,
+                      "isPure": false,
+                      "lValueRequested": true,
+                      "memberName": "length",
+                      "nodeType": "MemberAccess",
+                      "referencedDeclaration": null,
+                      "src": "31658:25:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_uint256",
+                        "typeString": "uint256"
+                      }
+                    },
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_uint256",
+                      "typeString": "uint256"
+                    }
+                  },
+                  "id": 1250,
+                  "nodeType": "ExpressionStatement",
+                  "src": "31658:27:1"
+                }
+              ]
+            },
+            "documentation": "@dev Private function to remove a token from this extension's ownership-tracking data structures. Note that\nwhile the token is not assigned a new owner, the _ownedTokensIndex mapping is _not_ updated: this allows for\ngas optimizations e.g. when performing a transfer operation (avoiding double writes).\nThis has O(1) time complexity, but alters the order of the _ownedTokens array.\n@param from address representing the previous owner of the given token ID\n@param tokenId uint256 ID of the token to be removed from the tokens list of the given address",
+            "id": 1252,
+            "implemented": true,
+            "kind": "function",
+            "modifiers": [],
+            "name": "_removeTokenFromOwnerEnumeration",
+            "nodeType": "FunctionDefinition",
+            "parameters": {
+              "id": 1200,
+              "nodeType": "ParameterList",
+              "parameters": [
+                {
+                  "constant": false,
+                  "id": 1197,
+                  "name": "from",
+                  "nodeType": "VariableDeclaration",
+                  "scope": 1252,
+                  "src": "30815:12:1",
+                  "stateVariable": false,
+                  "storageLocation": "default",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_address",
+                    "typeString": "address"
+                  },
+                  "typeName": {
+                    "id": 1196,
+                    "name": "address",
+                    "nodeType": "ElementaryTypeName",
+                    "src": "30815:7:1",
+                    "stateMutability": "nonpayable",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_address",
+                      "typeString": "address"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                },
+                {
+                  "constant": false,
+                  "id": 1199,
+                  "name": "tokenId",
+                  "nodeType": "VariableDeclaration",
+                  "scope": 1252,
+                  "src": "30829:15:1",
+                  "stateVariable": false,
+                  "storageLocation": "default",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_uint256",
+                    "typeString": "uint256"
+                  },
+                  "typeName": {
+                    "id": 1198,
+                    "name": "uint256",
+                    "nodeType": "ElementaryTypeName",
+                    "src": "30829:7:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_uint256",
+                      "typeString": "uint256"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                }
+              ],
+              "src": "30814:31:1"
+            },
+            "returnParameters": {
+              "id": 1201,
+              "nodeType": "ParameterList",
+              "parameters": [],
+              "src": "30854:0:1"
+            },
+            "scope": 1302,
+            "src": "30773:1128:1",
+            "stateMutability": "nonpayable",
+            "superFunction": null,
+            "visibility": "private"
+          },
+          {
+            "body": {
+              "id": 1300,
+              "nodeType": "Block",
+              "src": "32260:993:1",
+              "statements": [
+                {
+                  "assignments": [
+                    1258
+                  ],
+                  "declarations": [
+                    {
+                      "constant": false,
+                      "id": 1258,
+                      "name": "lastTokenIndex",
+                      "nodeType": "VariableDeclaration",
+                      "scope": 1300,
+                      "src": "32438:22:1",
+                      "stateVariable": false,
+                      "storageLocation": "default",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_uint256",
+                        "typeString": "uint256"
+                      },
+                      "typeName": {
+                        "id": 1257,
+                        "name": "uint256",
+                        "nodeType": "ElementaryTypeName",
+                        "src": "32438:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      },
+                      "value": null,
+                      "visibility": "internal"
+                    }
+                  ],
+                  "id": 1264,
+                  "initialValue": {
+                    "argumentTypes": null,
+                    "arguments": [
+                      {
+                        "argumentTypes": null,
+                        "hexValue": "31",
+                        "id": 1262,
+                        "isConstant": false,
+                        "isLValue": false,
+                        "isPure": true,
+                        "kind": "number",
+                        "lValueRequested": false,
+                        "nodeType": "Literal",
+                        "src": "32485:1:1",
+                        "subdenomination": null,
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_rational_1_by_1",
+                          "typeString": "int_const 1"
+                        },
+                        "value": "1"
+                      }
+                    ],
+                    "expression": {
+                      "argumentTypes": [
+                        {
+                          "typeIdentifier": "t_rational_1_by_1",
+                          "typeString": "int_const 1"
+                        }
+                      ],
+                      "expression": {
+                        "argumentTypes": null,
+                        "expression": {
+                          "argumentTypes": null,
+                          "id": 1259,
+                          "name": "_allTokens",
+                          "nodeType": "Identifier",
+                          "overloadedDeclarations": [],
+                          "referencedDeclaration": 988,
+                          "src": "32463:10:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_array$_t_uint256_$dyn_storage",
+                            "typeString": "uint256[] storage ref"
+                          }
+                        },
+                        "id": 1260,
+                        "isConstant": false,
+                        "isLValue": true,
+                        "isPure": false,
+                        "lValueRequested": false,
+                        "memberName": "length",
+                        "nodeType": "MemberAccess",
+                        "referencedDeclaration": null,
+                        "src": "32463:17:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      },
+                      "id": 1261,
+                      "isConstant": false,
+                      "isLValue": false,
+                      "isPure": false,
+                      "lValueRequested": false,
+                      "memberName": "sub",
+                      "nodeType": "MemberAccess",
+                      "referencedDeclaration": 190,
+                      "src": "32463:21:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_function_internal_pure$_t_uint256_$_t_uint256_$returns$_t_uint256_$bound_to$_t_uint256_$",
+                        "typeString": "function (uint256,uint256) pure returns (uint256)"
+                      }
+                    },
+                    "id": 1263,
+                    "isConstant": false,
+                    "isLValue": false,
+                    "isPure": false,
+                    "kind": "functionCall",
+                    "lValueRequested": false,
+                    "names": [],
+                    "nodeType": "FunctionCall",
+                    "src": "32463:24:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_uint256",
+                      "typeString": "uint256"
+                    }
+                  },
+                  "nodeType": "VariableDeclarationStatement",
+                  "src": "32438:49:1"
+                },
+                {
+                  "assignments": [
+                    1266
+                  ],
+                  "declarations": [
+                    {
+                      "constant": false,
+                      "id": 1266,
+                      "name": "tokenIndex",
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+                        "src": "36290:5:1",
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+                          "typeString": "address"
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+                        "src": "36278:5:1",
+                        "typeDescriptions": {
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+                              "src": "36361:10:1",
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+                        "typeString": "int_const 0"
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+                          "nodeType": "UnaryOperation",
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+                          "prefix": true,
+                          "src": "36409:26:1",
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+                              "nodeType": "Identifier",
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+                              "src": "36416:10:1",
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+              ]
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+        "src": "33817:2637:1"
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+        "literals": [
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+        "src": "36518:23:1"
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+            "baseName": {
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+              "id": 1450,
+              "name": "ERC721",
+              "nodeType": "UserDefinedTypeName",
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+              "src": "36838:6:1",
+              "typeDescriptions": {
+                "typeIdentifier": "t_contract$_ERC721_$944",
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+            "nodeType": "InheritanceSpecifier",
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+              "nodeType": "UserDefinedTypeName",
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+              "src": "36846:16:1",
+              "typeDescriptions": {
+                "typeIdentifier": "t_contract$_ERC721Enumerable_$1302",
+                "typeString": "contract ERC721Enumerable"
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+            "nodeType": "InheritanceSpecifier",
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+              "name": "ERC721Metadata",
+              "nodeType": "UserDefinedTypeName",
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+              "src": "36864:14:1",
+              "typeDescriptions": {
+                "typeIdentifier": "t_contract$_ERC721Metadata_$1448",
+                "typeString": "contract ERC721Metadata"
+              }
+            },
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+            "nodeType": "InheritanceSpecifier",
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+        ],
+        "contractKind": "contract",
+        "documentation": "@title Full ERC721 Token\nThis implementation includes all the required and some optional functionality of the ERC721 standard\nMoreover, it includes approve all functionality using operator terminology\n@dev see https://eips.ethereum.org/EIPS/eip-721",
+        "fullyImplemented": true,
+        "id": 1468,
+        "linearizedBaseContracts": [
+          1468,
+          1448,
+          1323,
+          1302,
+          969,
+          944,
+          124,
+          386,
+          23
+        ],
+        "name": "ERC721Full",
+        "nodeType": "ContractDefinition",
+        "nodes": [
+          {
+            "body": {
+              "id": 1466,
+              "nodeType": "Block",
+              "src": "36976:64:1",
+              "statements": []
+            },
+            "documentation": null,
+            "id": 1467,
+            "implemented": true,
+            "kind": "constructor",
+            "modifiers": [
+              {
+                "arguments": [
+                  {
+                    "argumentTypes": null,
+                    "id": 1462,
+                    "name": "name",
+                    "nodeType": "Identifier",
+                    "overloadedDeclarations": [],
+                    "referencedDeclaration": 1457,
+                    "src": "36962:4:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_string_memory_ptr",
+                      "typeString": "string memory"
+                    }
+                  },
+                  {
+                    "argumentTypes": null,
+                    "id": 1463,
+                    "name": "symbol",
+                    "nodeType": "Identifier",
+                    "overloadedDeclarations": [],
+                    "referencedDeclaration": 1459,
+                    "src": "36968:6:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_string_memory_ptr",
+                      "typeString": "string memory"
+                    }
+                  }
+                ],
+                "id": 1464,
+                "modifierName": {
+                  "argumentTypes": null,
+                  "id": 1461,
+                  "name": "ERC721Metadata",
+                  "nodeType": "Identifier",
+                  "overloadedDeclarations": [],
+                  "referencedDeclaration": 1448,
+                  "src": "36947:14:1",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_type$_t_contract$_ERC721Metadata_$1448_$",
+                    "typeString": "type(contract ERC721Metadata)"
+                  }
+                },
+                "nodeType": "ModifierInvocation",
+                "src": "36947:28:1"
+              }
+            ],
+            "name": "",
+            "nodeType": "FunctionDefinition",
+            "parameters": {
+              "id": 1460,
+              "nodeType": "ParameterList",
+              "parameters": [
+                {
+                  "constant": false,
+                  "id": 1457,
+                  "name": "name",
+                  "nodeType": "VariableDeclaration",
+                  "scope": 1467,
+                  "src": "36898:18:1",
+                  "stateVariable": false,
+                  "storageLocation": "memory",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_string_memory_ptr",
+                    "typeString": "string"
+                  },
+                  "typeName": {
+                    "id": 1456,
+                    "name": "string",
+                    "nodeType": "ElementaryTypeName",
+                    "src": "36898:6:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_string_storage_ptr",
+                      "typeString": "string"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                },
+                {
+                  "constant": false,
+                  "id": 1459,
+                  "name": "symbol",
+                  "nodeType": "VariableDeclaration",
+                  "scope": 1467,
+                  "src": "36918:20:1",
+                  "stateVariable": false,
+                  "storageLocation": "memory",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_string_memory_ptr",
+                    "typeString": "string"
+                  },
+                  "typeName": {
+                    "id": 1458,
+                    "name": "string",
+                    "nodeType": "ElementaryTypeName",
+                    "src": "36918:6:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_string_storage_ptr",
+                      "typeString": "string"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                }
+              ],
+              "src": "36897:42:1"
+            },
+            "returnParameters": {
+              "id": 1465,
+              "nodeType": "ParameterList",
+              "parameters": [],
+              "src": "36976:0:1"
+            },
+            "scope": 1468,
+            "src": "36885:155:1",
+            "stateMutability": "nonpayable",
+            "superFunction": null,
+            "visibility": "public"
+          }
+        ],
+        "scope": 1469,
+        "src": "36815:227:1"
+      }
+    ],
+    "src": "61:36982:1"
+  },
+  "compiler": {
+    "name": "solc",
+    "version": "0.5.0+commit.1d4f565a.Emscripten.clang"
+  },
+  "networks": {},
+  "schemaVersion": "3.0.2",
+  "updatedAt": "2019-09-05T15:01:08.626Z",
+  "devdoc": {
+    "details": "See https://eips.ethereum.org/EIPS/eip-721",
+    "methods": {
+      "approve(address,uint256)": {
+        "details": "Approves another address to transfer the given token ID The zero address indicates there is no approved address. There can only be one approved address per token at a given time. Can only be called by the token owner or an approved operator.",
+        "params": {
+          "to": "address to be approved for the given token ID",
+          "tokenId": "uint256 ID of the token to be approved"
+        }
+      },
+      "balanceOf(address)": {
+        "details": "Gets the balance of the specified address.",
+        "params": {
+          "owner": "address to query the balance of"
+        },
+        "return": "uint256 representing the amount owned by the passed address"
+      },
+      "constructor": {
+        "details": "Constructor function."
+      },
+      "getApproved(uint256)": {
+        "details": "Gets the approved address for a token ID, or zero if no address set Reverts if the token ID does not exist.",
+        "params": {
+          "tokenId": "uint256 ID of the token to query the approval of"
+        },
+        "return": "address currently approved for the given token ID"
+      },
+      "isApprovedForAll(address,address)": {
+        "details": "Tells whether an operator is approved by a given owner.",
+        "params": {
+          "operator": "operator address which you want to query the approval of",
+          "owner": "owner address which you want to query the approval of"
+        },
+        "return": "bool whether the given operator is approved by the given owner"
+      },
+      "ownerOf(uint256)": {
+        "details": "Gets the owner of the specified token ID.",
+        "params": {
+          "tokenId": "uint256 ID of the token to query the owner of"
+        },
+        "return": "address currently marked as the owner of the given token ID"
+      },
+      "safeTransferFrom(address,address,uint256)": {
+        "details": "Safely transfers the ownership of a given token ID to another address If the target address is a contract, it must implement `onERC721Received`, which is called upon a safe transfer, and return the magic value `bytes4(keccak256(\"onERC721Received(address,address,uint256,bytes)\"))`; otherwise, the transfer is reverted. Requires the msg.sender to be the owner, approved, or operator",
+        "params": {
+          "from": "current owner of the token",
+          "to": "address to receive the ownership of the given token ID",
+          "tokenId": "uint256 ID of the token to be transferred"
+        }
+      },
+      "safeTransferFrom(address,address,uint256,bytes)": {
+        "details": "Safely transfers the ownership of a given token ID to another address If the target address is a contract, it must implement `onERC721Received`, which is called upon a safe transfer, and return the magic value `bytes4(keccak256(\"onERC721Received(address,address,uint256,bytes)\"))`; otherwise, the transfer is reverted. Requires the msg.sender to be the owner, approved, or operator",
+        "params": {
+          "_data": "bytes data to send along with a safe transfer check",
+          "from": "current owner of the token",
+          "to": "address to receive the ownership of the given token ID",
+          "tokenId": "uint256 ID of the token to be transferred"
+        }
+      },
+      "setApprovalForAll(address,bool)": {
+        "details": "Sets or unsets the approval of a given operator An operator is allowed to transfer all tokens of the sender on their behalf.",
+        "params": {
+          "approved": "representing the status of the approval to be set",
+          "to": "operator address to set the approval"
+        }
+      },
+      "supportsInterface(bytes4)": {
+        "details": "See `IERC165.supportsInterface`.     * Time complexity O(1), guaranteed to always use less than 30 000 gas."
+      },
+      "tokenByIndex(uint256)": {
+        "details": "Gets the token ID at a given index of all the tokens in this contract Reverts if the index is greater or equal to the total number of tokens.",
+        "params": {
+          "index": "uint256 representing the index to be accessed of the tokens list"
+        },
+        "return": "uint256 token ID at the given index of the tokens list"
+      },
+      "tokenOfOwnerByIndex(address,uint256)": {
+        "details": "Gets the token ID at a given index of the tokens list of the requested owner.",
+        "params": {
+          "index": "uint256 representing the index to be accessed of the requested tokens list",
+          "owner": "address owning the tokens list to be accessed"
+        },
+        "return": "uint256 token ID at the given index of the tokens list owned by the requested address"
+      },
+      "totalSupply()": {
+        "details": "Gets the total amount of tokens stored by the contract.",
+        "return": "uint256 representing the total amount of tokens"
+      },
+      "transferFrom(address,address,uint256)": {
+        "details": "Transfers the ownership of a given token ID to another address. Usage of this method is discouraged, use `safeTransferFrom` whenever possible. Requires the msg.sender to be the owner, approved, or operator.",
+        "params": {
+          "from": "current owner of the token",
+          "to": "address to receive the ownership of the given token ID",
+          "tokenId": "uint256 ID of the token to be transferred"
+        }
+      }
+    },
+    "title": "ERC-721 Non-Fungible Token with optional enumeration extension logic"
+  },
+  "userdoc": {
+    "methods": {}
+  }
+}
\ No newline at end of file
diff --git a/src/abis/ERC721Full.json b/src/abis/ERC721Full.json
new file mode 100644
index 0000000..1f318c5
--- /dev/null
+++ b/src/abis/ERC721Full.json
@@ -0,0 +1,37944 @@
+{
+  "contractName": "ERC721Full",
+  "abi": [
+    {
+      "constant": true,
+      "inputs": [
+        {
+          "name": "interfaceId",
+          "type": "bytes4"
+        }
+      ],
+      "name": "supportsInterface",
+      "outputs": [
+        {
+          "name": "",
+          "type": "bool"
+        }
+      ],
+      "payable": false,
+      "stateMutability": "view",
+      "type": "function"
+    },
+    {
+      "constant": true,
+      "inputs": [],
+      "name": "name",
+      "outputs": [
+        {
+          "name": "",
+          "type": "string"
+        }
+      ],
+      "payable": false,
+      "stateMutability": "view",
+      "type": "function"
+    },
+    {
+      "constant": true,
+      "inputs": [
+        {
+          "name": "tokenId",
+          "type": "uint256"
+        }
+      ],
+      "name": "getApproved",
+      "outputs": [
+        {
+          "name": "",
+          "type": "address"
+        }
+      ],
+      "payable": false,
+      "stateMutability": "view",
+      "type": "function"
+    },
+    {
+      "constant": false,
+      "inputs": [
+        {
+          "name": "to",
+          "type": "address"
+        },
+        {
+          "name": "tokenId",
+          "type": "uint256"
+        }
+      ],
+      "name": "approve",
+      "outputs": [],
+      "payable": false,
+      "stateMutability": "nonpayable",
+      "type": "function"
+    },
+    {
+      "constant": true,
+      "inputs": [],
+      "name": "totalSupply",
+      "outputs": [
+        {
+          "name": "",
+          "type": "uint256"
+        }
+      ],
+      "payable": false,
+      "stateMutability": "view",
+      "type": "function"
+    },
+    {
+      "constant": false,
+      "inputs": [
+        {
+          "name": "from",
+          "type": "address"
+        },
+        {
+          "name": "to",
+          "type": "address"
+        },
+        {
+          "name": "tokenId",
+          "type": "uint256"
+        }
+      ],
+      "name": "transferFrom",
+      "outputs": [],
+      "payable": false,
+      "stateMutability": "nonpayable",
+      "type": "function"
+    },
+    {
+      "constant": true,
+      "inputs": [
+        {
+          "name": "owner",
+          "type": "address"
+        },
+        {
+          "name": "index",
+          "type": "uint256"
+        }
+      ],
+      "name": "tokenOfOwnerByIndex",
+      "outputs": [
+        {
+          "name": "",
+          "type": "uint256"
+        }
+      ],
+      "payable": false,
+      "stateMutability": "view",
+      "type": "function"
+    },
+    {
+      "constant": false,
+      "inputs": [
+        {
+          "name": "from",
+          "type": "address"
+        },
+        {
+          "name": "to",
+          "type": "address"
+        },
+        {
+          "name": "tokenId",
+          "type": "uint256"
+        }
+      ],
+      "name": "safeTransferFrom",
+      "outputs": [],
+      "payable": false,
+      "stateMutability": "nonpayable",
+      "type": "function"
+    },
+    {
+      "constant": true,
+      "inputs": [
+        {
+          "name": "index",
+          "type": "uint256"
+        }
+      ],
+      "name": "tokenByIndex",
+      "outputs": [
+        {
+          "name": "",
+          "type": "uint256"
+        }
+      ],
+      "payable": false,
+      "stateMutability": "view",
+      "type": "function"
+    },
+    {
+      "constant": true,
+      "inputs": [
+        {
+          "name": "tokenId",
+          "type": "uint256"
+        }
+      ],
+      "name": "ownerOf",
+      "outputs": [
+        {
+          "name": "",
+          "type": "address"
+        }
+      ],
+      "payable": false,
+      "stateMutability": "view",
+      "type": "function"
+    },
+    {
+      "constant": true,
+      "inputs": [
+        {
+          "name": "owner",
+          "type": "address"
+        }
+      ],
+      "name": "balanceOf",
+      "outputs": [
+        {
+          "name": "",
+          "type": "uint256"
+        }
+      ],
+      "payable": false,
+      "stateMutability": "view",
+      "type": "function"
+    },
+    {
+      "constant": true,
+      "inputs": [],
+      "name": "symbol",
+      "outputs": [
+        {
+          "name": "",
+          "type": "string"
+        }
+      ],
+      "payable": false,
+      "stateMutability": "view",
+      "type": "function"
+    },
+    {
+      "constant": false,
+      "inputs": [
+        {
+          "name": "to",
+          "type": "address"
+        },
+        {
+          "name": "approved",
+          "type": "bool"
+        }
+      ],
+      "name": "setApprovalForAll",
+      "outputs": [],
+      "payable": false,
+      "stateMutability": "nonpayable",
+      "type": "function"
+    },
+    {
+      "constant": false,
+      "inputs": [
+        {
+          "name": "from",
+          "type": "address"
+        },
+        {
+          "name": "to",
+          "type": "address"
+        },
+        {
+          "name": "tokenId",
+          "type": "uint256"
+        },
+        {
+          "name": "_data",
+          "type": "bytes"
+        }
+      ],
+      "name": "safeTransferFrom",
+      "outputs": [],
+      "payable": false,
+      "stateMutability": "nonpayable",
+      "type": "function"
+    },
+    {
+      "constant": true,
+      "inputs": [
+        {
+          "name": "tokenId",
+          "type": "uint256"
+        }
+      ],
+      "name": "tokenURI",
+      "outputs": [
+        {
+          "name": "",
+          "type": "string"
+        }
+      ],
+      "payable": false,
+      "stateMutability": "view",
+      "type": "function"
+    },
+    {
+      "constant": true,
+      "inputs": [
+        {
+          "name": "owner",
+          "type": "address"
+        },
+        {
+          "name": "operator",
+          "type": "address"
+        }
+      ],
+      "name": "isApprovedForAll",
+      "outputs": [
+        {
+          "name": "",
+          "type": "bool"
+        }
+      ],
+      "payable": false,
+      "stateMutability": "view",
+      "type": "function"
+    },
+    {
+      "inputs": [
+        {
+          "name": "name",
+          "type": "string"
+        },
+        {
+          "name": "symbol",
+          "type": "string"
+        }
+      ],
+      "payable": false,
+      "stateMutability": "nonpayable",
+      "type": "constructor"
+    },
+    {
+      "anonymous": false,
+      "inputs": [
+        {
+          "indexed": true,
+          "name": "from",
+          "type": "address"
+        },
+        {
+          "indexed": true,
+          "name": "to",
+          "type": "address"
+        },
+        {
+          "indexed": true,
+          "name": "tokenId",
+          "type": "uint256"
+        }
+      ],
+      "name": "Transfer",
+      "type": "event"
+    },
+    {
+      "anonymous": false,
+      "inputs": [
+        {
+          "indexed": true,
+          "name": "owner",
+          "type": "address"
+        },
+        {
+          "indexed": true,
+          "name": "approved",
+          "type": "address"
+        },
+        {
+          "indexed": true,
+          "name": "tokenId",
+          "type": "uint256"
+        }
+      ],
+      "name": "Approval",
+      "type": "event"
+    },
+    {
+      "anonymous": false,
+      "inputs": [
+        {
+          "indexed": true,
+          "name": "owner",
+          "type": "address"
+        },
+        {
+          "indexed": true,
+          "name": "operator",
+          "type": "address"
+        },
+        {
+          "indexed": false,
+          "name": "approved",
+          "type": "bool"
+        }
+      ],
+      "name": "ApprovalForAll",
+      "type": "event"
+    }
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+  "source": "\n// File: @openzeppelin/contracts/introspection/IERC165.sol\n\npragma solidity ^0.5.0;\n\n/**\n * @dev Interface of the ERC165 standard, as defined in the\n * [EIP](https://eips.ethereum.org/EIPS/eip-165).\n *\n * Implementers can declare support of contract interfaces, which can then be\n * queried by others (`ERC165Checker`).\n *\n * For an implementation, see `ERC165`.\n */\ninterface IERC165 {\n    /**\n     * @dev Returns true if this contract implements the interface defined by\n     * `interfaceId`. See the corresponding\n     * [EIP section](https://eips.ethereum.org/EIPS/eip-165#how-interfaces-are-identified)\n     * to learn more about how these ids are created.\n     *\n     * This function call must use less than 30 000 gas.\n     */\n    function supportsInterface(bytes4 interfaceId) external view returns (bool);\n}\n\n// File: @openzeppelin/contracts/token/ERC721/IERC721.sol\n\npragma solidity ^0.5.0;\n\n\n/**\n * @dev Required interface of an ERC721 compliant contract.\n */\ncontract IERC721 is IERC165 {\n    event Transfer(address indexed from, address indexed to, uint256 indexed tokenId);\n    event Approval(address indexed owner, address indexed approved, uint256 indexed tokenId);\n    event ApprovalForAll(address indexed owner, address indexed operator, bool approved);\n\n    /**\n     * @dev Returns the number of NFTs in `owner`'s account.\n     */\n    function balanceOf(address owner) public view returns (uint256 balance);\n\n    /**\n     * @dev Returns the owner of the NFT specified by `tokenId`.\n     */\n    function ownerOf(uint256 tokenId) public view returns (address owner);\n\n    /**\n     * @dev Transfers a specific NFT (`tokenId`) from one account (`from`) to\n     * another (`to`).\n     *\n     * \n     *\n     * Requirements:\n     * - `from`, `to` cannot be zero.\n     * - `tokenId` must be owned by `from`.\n     * - If the caller is not `from`, it must be have been allowed to move this\n     * NFT by either `approve` or `setApproveForAll`.\n     */\n    function safeTransferFrom(address from, address to, uint256 tokenId) public;\n    /**\n     * @dev Transfers a specific NFT (`tokenId`) from one account (`from`) to\n     * another (`to`).\n     *\n     * Requirements:\n     * - If the caller is not `from`, it must be approved to move this NFT by\n     * either `approve` or `setApproveForAll`.\n     */\n    function transferFrom(address from, address to, uint256 tokenId) public;\n    function approve(address to, uint256 tokenId) public;\n    function getApproved(uint256 tokenId) public view returns (address operator);\n\n    function setApprovalForAll(address operator, bool _approved) public;\n    function isApprovedForAll(address owner, address operator) public view returns (bool);\n\n\n    function safeTransferFrom(address from, address to, uint256 tokenId, bytes memory data) public;\n}\n\n// File: @openzeppelin/contracts/token/ERC721/IERC721Receiver.sol\n\npragma solidity ^0.5.0;\n\n/**\n * @title ERC721 token receiver interface\n * @dev Interface for any contract that wants to support safeTransfers\n * from ERC721 asset contracts.\n */\ncontract IERC721Receiver {\n    /**\n     * @notice Handle the receipt of an NFT\n     * @dev The ERC721 smart contract calls this function on the recipient\n     * after a `safeTransfer`. This function MUST return the function selector,\n     * otherwise the caller will revert the transaction. The selector to be\n     * returned can be obtained as `this.onERC721Received.selector`. This\n     * function MAY throw to revert and reject the transfer.\n     * Note: the ERC721 contract address is always the message sender.\n     * @param operator The address which called `safeTransferFrom` function\n     * @param from The address which previously owned the token\n     * @param tokenId The NFT identifier which is being transferred\n     * @param data Additional data with no specified format\n     * @return bytes4 `bytes4(keccak256(\"onERC721Received(address,address,uint256,bytes)\"))`\n     */\n    function onERC721Received(address operator, address from, uint256 tokenId, bytes memory data)\n    public returns (bytes4);\n}\n\n// File: @openzeppelin/contracts/math/SafeMath.sol\n\npragma solidity ^0.5.0;\n\n/**\n * @dev Wrappers over Solidity's arithmetic operations with added overflow\n * checks.\n *\n * Arithmetic operations in Solidity wrap on overflow. This can easily result\n * in bugs, because programmers usually assume that an overflow raises an\n * error, which is the standard behavior in high level programming languages.\n * `SafeMath` restores this intuition by reverting the transaction when an\n * operation overflows.\n *\n * Using this library instead of the unchecked operations eliminates an entire\n * class of bugs, so it's recommended to use it always.\n */\nlibrary SafeMath {\n    /**\n     * @dev Returns the addition of two unsigned integers, reverting on\n     * overflow.\n     *\n     * Counterpart to Solidity's `+` operator.\n     *\n     * Requirements:\n     * - Addition cannot overflow.\n     */\n    function add(uint256 a, uint256 b) internal pure returns (uint256) {\n        uint256 c = a + b;\n        require(c >= a, \"SafeMath: addition overflow\");\n\n        return c;\n    }\n\n    /**\n     * @dev Returns the subtraction of two unsigned integers, reverting on\n     * overflow (when the result is negative).\n     *\n     * Counterpart to Solidity's `-` operator.\n     *\n     * Requirements:\n     * - Subtraction cannot overflow.\n     */\n    function sub(uint256 a, uint256 b) internal pure returns (uint256) {\n        require(b <= a, \"SafeMath: subtraction overflow\");\n        uint256 c = a - b;\n\n        return c;\n    }\n\n    /**\n     * @dev Returns the multiplication of two unsigned integers, reverting on\n     * overflow.\n     *\n     * Counterpart to Solidity's `*` operator.\n     *\n     * Requirements:\n     * - Multiplication cannot overflow.\n     */\n    function mul(uint256 a, uint256 b) internal pure returns (uint256) {\n        // Gas optimization: this is cheaper than requiring 'a' not being zero, but the\n        // benefit is lost if 'b' is also tested.\n        // See: https://github.com/OpenZeppelin/openzeppelin-contracts/pull/522\n        if (a == 0) {\n            return 0;\n        }\n\n        uint256 c = a * b;\n        require(c / a == b, \"SafeMath: multiplication overflow\");\n\n        return c;\n    }\n\n    /**\n     * @dev Returns the integer division of two unsigned integers. Reverts on\n     * division by zero. The result is rounded towards zero.\n     *\n     * Counterpart to Solidity's `/` operator. Note: this function uses a\n     * `revert` opcode (which leaves remaining gas untouched) while Solidity\n     * uses an invalid opcode to revert (consuming all remaining gas).\n     *\n     * Requirements:\n     * - The divisor cannot be zero.\n     */\n    function div(uint256 a, uint256 b) internal pure returns (uint256) {\n        // Solidity only automatically asserts when dividing by 0\n        require(b > 0, \"SafeMath: division by zero\");\n        uint256 c = a / b;\n        // assert(a == b * c + a % b); // There is no case in which this doesn't hold\n\n        return c;\n    }\n\n    /**\n     * @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo),\n     * Reverts when dividing by zero.\n     *\n     * Counterpart to Solidity's `%` operator. This function uses a `revert`\n     * opcode (which leaves remaining gas untouched) while Solidity uses an\n     * invalid opcode to revert (consuming all remaining gas).\n     *\n     * Requirements:\n     * - The divisor cannot be zero.\n     */\n    function mod(uint256 a, uint256 b) internal pure returns (uint256) {\n        require(b != 0, \"SafeMath: modulo by zero\");\n        return a % b;\n    }\n}\n\n// File: @openzeppelin/contracts/utils/Address.sol\n\npragma solidity ^0.5.0;\n\n/**\n * @dev Collection of functions related to the address type,\n */\nlibrary Address {\n    /**\n     * @dev Returns true if `account` is a contract.\n     *\n     * This test is non-exhaustive, and there may be false-negatives: during the\n     * execution of a contract's constructor, its address will be reported as\n     * not containing a contract.\n     *\n     * > It is unsafe to assume that an address for which this function returns\n     * false is an externally-owned account (EOA) and not a contract.\n     */\n    function isContract(address account) internal view returns (bool) {\n        // This method relies in extcodesize, which returns 0 for contracts in\n        // construction, since the code is only stored at the end of the\n        // constructor execution.\n\n        uint256 size;\n        // solhint-disable-next-line no-inline-assembly\n        assembly { size := extcodesize(account) }\n        return size > 0;\n    }\n}\n\n// File: @openzeppelin/contracts/drafts/Counters.sol\n\npragma solidity ^0.5.0;\n\n\n/**\n * @title Counters\n * @author Matt Condon (@shrugs)\n * @dev Provides counters that can only be incremented or decremented by one. This can be used e.g. to track the number\n * of elements in a mapping, issuing ERC721 ids, or counting request ids.\n *\n * Include with `using Counters for Counters.Counter;`\n * Since it is not possible to overflow a 256 bit integer with increments of one, `increment` can skip the SafeMath\n * overflow check, thereby saving gas. This does assume however correct usage, in that the underlying `_value` is never\n * directly accessed.\n */\nlibrary Counters {\n    using SafeMath for uint256;\n\n    struct Counter {\n        // This variable should never be directly accessed by users of the library: interactions must be restricted to\n        // the library's function. As of Solidity v0.5.2, this cannot be enforced, though there is a proposal to add\n        // this feature: see https://github.com/ethereum/solidity/issues/4637\n        uint256 _value; // default: 0\n    }\n\n    function current(Counter storage counter) internal view returns (uint256) {\n        return counter._value;\n    }\n\n    function increment(Counter storage counter) internal {\n        counter._value += 1;\n    }\n\n    function decrement(Counter storage counter) internal {\n        counter._value = counter._value.sub(1);\n    }\n}\n\n// File: @openzeppelin/contracts/introspection/ERC165.sol\n\npragma solidity ^0.5.0;\n\n\n/**\n * @dev Implementation of the `IERC165` interface.\n *\n * Contracts may inherit from this and call `_registerInterface` to declare\n * their support of an interface.\n */\ncontract ERC165 is IERC165 {\n    /*\n     * bytes4(keccak256('supportsInterface(bytes4)')) == 0x01ffc9a7\n     */\n    bytes4 private constant _INTERFACE_ID_ERC165 = 0x01ffc9a7;\n\n    /**\n     * @dev Mapping of interface ids to whether or not it's supported.\n     */\n    mapping(bytes4 => bool) private _supportedInterfaces;\n\n    constructor () internal {\n        // Derived contracts need only register support for their own interfaces,\n        // we register support for ERC165 itself here\n        _registerInterface(_INTERFACE_ID_ERC165);\n    }\n\n    /**\n     * @dev See `IERC165.supportsInterface`.\n     *\n     * Time complexity O(1), guaranteed to always use less than 30 000 gas.\n     */\n    function supportsInterface(bytes4 interfaceId) external view returns (bool) {\n        return _supportedInterfaces[interfaceId];\n    }\n\n    /**\n     * @dev Registers the contract as an implementer of the interface defined by\n     * `interfaceId`. Support of the actual ERC165 interface is automatic and\n     * registering its interface id is not required.\n     *\n     * See `IERC165.supportsInterface`.\n     *\n     * Requirements:\n     *\n     * - `interfaceId` cannot be the ERC165 invalid interface (`0xffffffff`).\n     */\n    function _registerInterface(bytes4 interfaceId) internal {\n        require(interfaceId != 0xffffffff, \"ERC165: invalid interface id\");\n        _supportedInterfaces[interfaceId] = true;\n    }\n}\n\n// File: @openzeppelin/contracts/token/ERC721/ERC721.sol\n\npragma solidity ^0.5.0;\n\n\n\n\n\n\n\n/**\n * @title ERC721 Non-Fungible Token Standard basic implementation\n * @dev see https://eips.ethereum.org/EIPS/eip-721\n */\ncontract ERC721 is ERC165, IERC721 {\n    using SafeMath for uint256;\n    using Address for address;\n    using Counters for Counters.Counter;\n\n    // Equals to `bytes4(keccak256(\"onERC721Received(address,address,uint256,bytes)\"))`\n    // which can be also obtained as `IERC721Receiver(0).onERC721Received.selector`\n    bytes4 private constant _ERC721_RECEIVED = 0x150b7a02;\n\n    // Mapping from token ID to owner\n    mapping (uint256 => address) private _tokenOwner;\n\n    // Mapping from token ID to approved address\n    mapping (uint256 => address) private _tokenApprovals;\n\n    // Mapping from owner to number of owned token\n    mapping (address => Counters.Counter) private _ownedTokensCount;\n\n    // Mapping from owner to operator approvals\n    mapping (address => mapping (address => bool)) private _operatorApprovals;\n\n    /*\n     *     bytes4(keccak256('balanceOf(address)')) == 0x70a08231\n     *     bytes4(keccak256('ownerOf(uint256)')) == 0x6352211e\n     *     bytes4(keccak256('approve(address,uint256)')) == 0x095ea7b3\n     *     bytes4(keccak256('getApproved(uint256)')) == 0x081812fc\n     *     bytes4(keccak256('setApprovalForAll(address,bool)')) == 0xa22cb465\n     *     bytes4(keccak256('isApprovedForAll(address,address)')) == 0xe985e9c\n     *     bytes4(keccak256('transferFrom(address,address,uint256)')) == 0x23b872dd\n     *     bytes4(keccak256('safeTransferFrom(address,address,uint256)')) == 0x42842e0e\n     *     bytes4(keccak256('safeTransferFrom(address,address,uint256,bytes)')) == 0xb88d4fde\n     *\n     *     => 0x70a08231 ^ 0x6352211e ^ 0x095ea7b3 ^ 0x081812fc ^\n     *        0xa22cb465 ^ 0xe985e9c ^ 0x23b872dd ^ 0x42842e0e ^ 0xb88d4fde == 0x80ac58cd\n     */\n    bytes4 private constant _INTERFACE_ID_ERC721 = 0x80ac58cd;\n\n    constructor () public {\n        // register the supported interfaces to conform to ERC721 via ERC165\n        _registerInterface(_INTERFACE_ID_ERC721);\n    }\n\n    /**\n     * @dev Gets the balance of the specified address.\n     * @param owner address to query the balance of\n     * @return uint256 representing the amount owned by the passed address\n     */\n    function balanceOf(address owner) public view returns (uint256) {\n        require(owner != address(0), \"ERC721: balance query for the zero address\");\n\n        return _ownedTokensCount[owner].current();\n    }\n\n    /**\n     * @dev Gets the owner of the specified token ID.\n     * @param tokenId uint256 ID of the token to query the owner of\n     * @return address currently marked as the owner of the given token ID\n     */\n    function ownerOf(uint256 tokenId) public view returns (address) {\n        address owner = _tokenOwner[tokenId];\n        require(owner != address(0), \"ERC721: owner query for nonexistent token\");\n\n        return owner;\n    }\n\n    /**\n     * @dev Approves another address to transfer the given token ID\n     * The zero address indicates there is no approved address.\n     * There can only be one approved address per token at a given time.\n     * Can only be called by the token owner or an approved operator.\n     * @param to address to be approved for the given token ID\n     * @param tokenId uint256 ID of the token to be approved\n     */\n    function approve(address to, uint256 tokenId) public {\n        address owner = ownerOf(tokenId);\n        require(to != owner, \"ERC721: approval to current owner\");\n\n        require(msg.sender == owner || isApprovedForAll(owner, msg.sender),\n            \"ERC721: approve caller is not owner nor approved for all\"\n        );\n\n        _tokenApprovals[tokenId] = to;\n        emit Approval(owner, to, tokenId);\n    }\n\n    /**\n     * @dev Gets the approved address for a token ID, or zero if no address set\n     * Reverts if the token ID does not exist.\n     * @param tokenId uint256 ID of the token to query the approval of\n     * @return address currently approved for the given token ID\n     */\n    function getApproved(uint256 tokenId) public view returns (address) {\n        require(_exists(tokenId), \"ERC721: approved query for nonexistent token\");\n\n        return _tokenApprovals[tokenId];\n    }\n\n    /**\n     * @dev Sets or unsets the approval of a given operator\n     * An operator is allowed to transfer all tokens of the sender on their behalf.\n     * @param to operator address to set the approval\n     * @param approved representing the status of the approval to be set\n     */\n    function setApprovalForAll(address to, bool approved) public {\n        require(to != msg.sender, \"ERC721: approve to caller\");\n\n        _operatorApprovals[msg.sender][to] = approved;\n        emit ApprovalForAll(msg.sender, to, approved);\n    }\n\n    /**\n     * @dev Tells whether an operator is approved by a given owner.\n     * @param owner owner address which you want to query the approval of\n     * @param operator operator address which you want to query the approval of\n     * @return bool whether the given operator is approved by the given owner\n     */\n    function isApprovedForAll(address owner, address operator) public view returns (bool) {\n        return _operatorApprovals[owner][operator];\n    }\n\n    /**\n     * @dev Transfers the ownership of a given token ID to another address.\n     * Usage of this method is discouraged, use `safeTransferFrom` whenever possible.\n     * Requires the msg.sender to be the owner, approved, or operator.\n     * @param from current owner of the token\n     * @param to address to receive the ownership of the given token ID\n     * @param tokenId uint256 ID of the token to be transferred\n     */\n    function transferFrom(address from, address to, uint256 tokenId) public {\n        //solhint-disable-next-line max-line-length\n        require(_isApprovedOrOwner(msg.sender, tokenId), \"ERC721: transfer caller is not owner nor approved\");\n\n        _transferFrom(from, to, tokenId);\n    }\n\n    /**\n     * @dev Safely transfers the ownership of a given token ID to another address\n     * If the target address is a contract, it must implement `onERC721Received`,\n     * which is called upon a safe transfer, and return the magic value\n     * `bytes4(keccak256(\"onERC721Received(address,address,uint256,bytes)\"))`; otherwise,\n     * the transfer is reverted.\n     * Requires the msg.sender to be the owner, approved, or operator\n     * @param from current owner of the token\n     * @param to address to receive the ownership of the given token ID\n     * @param tokenId uint256 ID of the token to be transferred\n     */\n    function safeTransferFrom(address from, address to, uint256 tokenId) public {\n        safeTransferFrom(from, to, tokenId, \"\");\n    }\n\n    /**\n     * @dev Safely transfers the ownership of a given token ID to another address\n     * If the target address is a contract, it must implement `onERC721Received`,\n     * which is called upon a safe transfer, and return the magic value\n     * `bytes4(keccak256(\"onERC721Received(address,address,uint256,bytes)\"))`; otherwise,\n     * the transfer is reverted.\n     * Requires the msg.sender to be the owner, approved, or operator\n     * @param from current owner of the token\n     * @param to address to receive the ownership of the given token ID\n     * @param tokenId uint256 ID of the token to be transferred\n     * @param _data bytes data to send along with a safe transfer check\n     */\n    function safeTransferFrom(address from, address to, uint256 tokenId, bytes memory _data) public {\n        transferFrom(from, to, tokenId);\n        require(_checkOnERC721Received(from, to, tokenId, _data), \"ERC721: transfer to non ERC721Receiver implementer\");\n    }\n\n    /**\n     * @dev Returns whether the specified token exists.\n     * @param tokenId uint256 ID of the token to query the existence of\n     * @return bool whether the token exists\n     */\n    function _exists(uint256 tokenId) internal view returns (bool) {\n        address owner = _tokenOwner[tokenId];\n        return owner != address(0);\n    }\n\n    /**\n     * @dev Returns whether the given spender can transfer a given token ID.\n     * @param spender address of the spender to query\n     * @param tokenId uint256 ID of the token to be transferred\n     * @return bool whether the msg.sender is approved for the given token ID,\n     * is an operator of the owner, or is the owner of the token\n     */\n    function _isApprovedOrOwner(address spender, uint256 tokenId) internal view returns (bool) {\n        require(_exists(tokenId), \"ERC721: operator query for nonexistent token\");\n        address owner = ownerOf(tokenId);\n        return (spender == owner || getApproved(tokenId) == spender || isApprovedForAll(owner, spender));\n    }\n\n    /**\n     * @dev Internal function to mint a new token.\n     * Reverts if the given token ID already exists.\n     * @param to The address that will own the minted token\n     * @param tokenId uint256 ID of the token to be minted\n     */\n    function _mint(address to, uint256 tokenId) internal {\n        require(to != address(0), \"ERC721: mint to the zero address\");\n        require(!_exists(tokenId), \"ERC721: token already minted\");\n\n        _tokenOwner[tokenId] = to;\n        _ownedTokensCount[to].increment();\n\n        emit Transfer(address(0), to, tokenId);\n    }\n\n    /**\n     * @dev Internal function to burn a specific token.\n     * Reverts if the token does not exist.\n     * Deprecated, use _burn(uint256) instead.\n     * @param owner owner of the token to burn\n     * @param tokenId uint256 ID of the token being burned\n     */\n    function _burn(address owner, uint256 tokenId) internal {\n        require(ownerOf(tokenId) == owner, \"ERC721: burn of token that is not own\");\n\n        _clearApproval(tokenId);\n\n        _ownedTokensCount[owner].decrement();\n        _tokenOwner[tokenId] = address(0);\n\n        emit Transfer(owner, address(0), tokenId);\n    }\n\n    /**\n     * @dev Internal function to burn a specific token.\n     * Reverts if the token does not exist.\n     * @param tokenId uint256 ID of the token being burned\n     */\n    function _burn(uint256 tokenId) internal {\n        _burn(ownerOf(tokenId), tokenId);\n    }\n\n    /**\n     * @dev Internal function to transfer ownership of a given token ID to another address.\n     * As opposed to transferFrom, this imposes no restrictions on msg.sender.\n     * @param from current owner of the token\n     * @param to address to receive the ownership of the given token ID\n     * @param tokenId uint256 ID of the token to be transferred\n     */\n    function _transferFrom(address from, address to, uint256 tokenId) internal {\n        require(ownerOf(tokenId) == from, \"ERC721: transfer of token that is not own\");\n        require(to != address(0), \"ERC721: transfer to the zero address\");\n\n        _clearApproval(tokenId);\n\n        _ownedTokensCount[from].decrement();\n        _ownedTokensCount[to].increment();\n\n        _tokenOwner[tokenId] = to;\n\n        emit Transfer(from, to, tokenId);\n    }\n\n    /**\n     * @dev Internal function to invoke `onERC721Received` on a target address.\n     * The call is not executed if the target address is not a contract.\n     *\n     * This function is deprecated.\n     * @param from address representing the previous owner of the given token ID\n     * @param to target address that will receive the tokens\n     * @param tokenId uint256 ID of the token to be transferred\n     * @param _data bytes optional data to send along with the call\n     * @return bool whether the call correctly returned the expected magic value\n     */\n    function _checkOnERC721Received(address from, address to, uint256 tokenId, bytes memory _data)\n        internal returns (bool)\n    {\n        if (!to.isContract()) {\n            return true;\n        }\n\n        bytes4 retval = IERC721Receiver(to).onERC721Received(msg.sender, from, tokenId, _data);\n        return (retval == _ERC721_RECEIVED);\n    }\n\n    /**\n     * @dev Private function to clear current approval of a given token ID.\n     * @param tokenId uint256 ID of the token to be transferred\n     */\n    function _clearApproval(uint256 tokenId) private {\n        if (_tokenApprovals[tokenId] != address(0)) {\n            _tokenApprovals[tokenId] = address(0);\n        }\n    }\n}\n\n// File: @openzeppelin/contracts/token/ERC721/IERC721Enumerable.sol\n\npragma solidity ^0.5.0;\n\n\n/**\n * @title ERC-721 Non-Fungible Token Standard, optional enumeration extension\n * @dev See https://eips.ethereum.org/EIPS/eip-721\n */\ncontract IERC721Enumerable is IERC721 {\n    function totalSupply() public view returns (uint256);\n    function tokenOfOwnerByIndex(address owner, uint256 index) public view returns (uint256 tokenId);\n\n    function tokenByIndex(uint256 index) public view returns (uint256);\n}\n\n// File: @openzeppelin/contracts/token/ERC721/ERC721Enumerable.sol\n\npragma solidity ^0.5.0;\n\n\n\n\n/**\n * @title ERC-721 Non-Fungible Token with optional enumeration extension logic\n * @dev See https://eips.ethereum.org/EIPS/eip-721\n */\ncontract ERC721Enumerable is ERC165, ERC721, IERC721Enumerable {\n    // Mapping from owner to list of owned token IDs\n    mapping(address => uint256[]) private _ownedTokens;\n\n    // Mapping from token ID to index of the owner tokens list\n    mapping(uint256 => uint256) private _ownedTokensIndex;\n\n    // Array with all token ids, used for enumeration\n    uint256[] private _allTokens;\n\n    // Mapping from token id to position in the allTokens array\n    mapping(uint256 => uint256) private _allTokensIndex;\n\n    /*\n     *     bytes4(keccak256('totalSupply()')) == 0x18160ddd\n     *     bytes4(keccak256('tokenOfOwnerByIndex(address,uint256)')) == 0x2f745c59\n     *     bytes4(keccak256('tokenByIndex(uint256)')) == 0x4f6ccce7\n     *\n     *     => 0x18160ddd ^ 0x2f745c59 ^ 0x4f6ccce7 == 0x780e9d63\n     */\n    bytes4 private constant _INTERFACE_ID_ERC721_ENUMERABLE = 0x780e9d63;\n\n    /**\n     * @dev Constructor function.\n     */\n    constructor () public {\n        // register the supported interface to conform to ERC721Enumerable via ERC165\n        _registerInterface(_INTERFACE_ID_ERC721_ENUMERABLE);\n    }\n\n    /**\n     * @dev Gets the token ID at a given index of the tokens list of the requested owner.\n     * @param owner address owning the tokens list to be accessed\n     * @param index uint256 representing the index to be accessed of the requested tokens list\n     * @return uint256 token ID at the given index of the tokens list owned by the requested address\n     */\n    function tokenOfOwnerByIndex(address owner, uint256 index) public view returns (uint256) {\n        require(index < balanceOf(owner), \"ERC721Enumerable: owner index out of bounds\");\n        return _ownedTokens[owner][index];\n    }\n\n    /**\n     * @dev Gets the total amount of tokens stored by the contract.\n     * @return uint256 representing the total amount of tokens\n     */\n    function totalSupply() public view returns (uint256) {\n        return _allTokens.length;\n    }\n\n    /**\n     * @dev Gets the token ID at a given index of all the tokens in this contract\n     * Reverts if the index is greater or equal to the total number of tokens.\n     * @param index uint256 representing the index to be accessed of the tokens list\n     * @return uint256 token ID at the given index of the tokens list\n     */\n    function tokenByIndex(uint256 index) public view returns (uint256) {\n        require(index < totalSupply(), \"ERC721Enumerable: global index out of bounds\");\n        return _allTokens[index];\n    }\n\n    /**\n     * @dev Internal function to transfer ownership of a given token ID to another address.\n     * As opposed to transferFrom, this imposes no restrictions on msg.sender.\n     * @param from current owner of the token\n     * @param to address to receive the ownership of the given token ID\n     * @param tokenId uint256 ID of the token to be transferred\n     */\n    function _transferFrom(address from, address to, uint256 tokenId) internal {\n        super._transferFrom(from, to, tokenId);\n\n        _removeTokenFromOwnerEnumeration(from, tokenId);\n\n        _addTokenToOwnerEnumeration(to, tokenId);\n    }\n\n    /**\n     * @dev Internal function to mint a new token.\n     * Reverts if the given token ID already exists.\n     * @param to address the beneficiary that will own the minted token\n     * @param tokenId uint256 ID of the token to be minted\n     */\n    function _mint(address to, uint256 tokenId) internal {\n        super._mint(to, tokenId);\n\n        _addTokenToOwnerEnumeration(to, tokenId);\n\n        _addTokenToAllTokensEnumeration(tokenId);\n    }\n\n    /**\n     * @dev Internal function to burn a specific token.\n     * Reverts if the token does not exist.\n     * Deprecated, use _burn(uint256) instead.\n     * @param owner owner of the token to burn\n     * @param tokenId uint256 ID of the token being burned\n     */\n    function _burn(address owner, uint256 tokenId) internal {\n        super._burn(owner, tokenId);\n\n        _removeTokenFromOwnerEnumeration(owner, tokenId);\n        // Since tokenId will be deleted, we can clear its slot in _ownedTokensIndex to trigger a gas refund\n        _ownedTokensIndex[tokenId] = 0;\n\n        _removeTokenFromAllTokensEnumeration(tokenId);\n    }\n\n    /**\n     * @dev Gets the list of token IDs of the requested owner.\n     * @param owner address owning the tokens\n     * @return uint256[] List of token IDs owned by the requested address\n     */\n    function _tokensOfOwner(address owner) internal view returns (uint256[] storage) {\n        return _ownedTokens[owner];\n    }\n\n    /**\n     * @dev Private function to add a token to this extension's ownership-tracking data structures.\n     * @param to address representing the new owner of the given token ID\n     * @param tokenId uint256 ID of the token to be added to the tokens list of the given address\n     */\n    function _addTokenToOwnerEnumeration(address to, uint256 tokenId) private {\n        _ownedTokensIndex[tokenId] = _ownedTokens[to].length;\n        _ownedTokens[to].push(tokenId);\n    }\n\n    /**\n     * @dev Private function to add a token to this extension's token tracking data structures.\n     * @param tokenId uint256 ID of the token to be added to the tokens list\n     */\n    function _addTokenToAllTokensEnumeration(uint256 tokenId) private {\n        _allTokensIndex[tokenId] = _allTokens.length;\n        _allTokens.push(tokenId);\n    }\n\n    /**\n     * @dev Private function to remove a token from this extension's ownership-tracking data structures. Note that\n     * while the token is not assigned a new owner, the _ownedTokensIndex mapping is _not_ updated: this allows for\n     * gas optimizations e.g. when performing a transfer operation (avoiding double writes).\n     * This has O(1) time complexity, but alters the order of the _ownedTokens array.\n     * @param from address representing the previous owner of the given token ID\n     * @param tokenId uint256 ID of the token to be removed from the tokens list of the given address\n     */\n    function _removeTokenFromOwnerEnumeration(address from, uint256 tokenId) private {\n        // To prevent a gap in from's tokens array, we store the last token in the index of the token to delete, and\n        // then delete the last slot (swap and pop).\n\n        uint256 lastTokenIndex = _ownedTokens[from].length.sub(1);\n        uint256 tokenIndex = _ownedTokensIndex[tokenId];\n\n        // When the token to delete is the last token, the swap operation is unnecessary\n        if (tokenIndex != lastTokenIndex) {\n            uint256 lastTokenId = _ownedTokens[from][lastTokenIndex];\n\n            _ownedTokens[from][tokenIndex] = lastTokenId; // Move the last token to the slot of the to-delete token\n            _ownedTokensIndex[lastTokenId] = tokenIndex; // Update the moved token's index\n        }\n\n        // This also deletes the contents at the last position of the array\n        _ownedTokens[from].length--;\n\n        // Note that _ownedTokensIndex[tokenId] hasn't been cleared: it still points to the old slot (now occupied by\n        // lastTokenId, or just over the end of the array if the token was the last one).\n    }\n\n    /**\n     * @dev Private function to remove a token from this extension's token tracking data structures.\n     * This has O(1) time complexity, but alters the order of the _allTokens array.\n     * @param tokenId uint256 ID of the token to be removed from the tokens list\n     */\n    function _removeTokenFromAllTokensEnumeration(uint256 tokenId) private {\n        // To prevent a gap in the tokens array, we store the last token in the index of the token to delete, and\n        // then delete the last slot (swap and pop).\n\n        uint256 lastTokenIndex = _allTokens.length.sub(1);\n        uint256 tokenIndex = _allTokensIndex[tokenId];\n\n        // When the token to delete is the last token, the swap operation is unnecessary. 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May return an empty string.\n     * @param tokenId uint256 ID of the token to query\n     */\n    function tokenURI(uint256 tokenId) external view returns (string memory) {\n        require(_exists(tokenId), \"ERC721Metadata: URI query for nonexistent token\");\n        return _tokenURIs[tokenId];\n    }\n\n    /**\n     * @dev Internal function to set the token URI for a given token.\n     * Reverts if the token ID does not exist.\n     * @param tokenId uint256 ID of the token to set its URI\n     * @param uri string URI to assign\n     */\n    function _setTokenURI(uint256 tokenId, string memory uri) internal {\n        require(_exists(tokenId), \"ERC721Metadata: URI set of nonexistent token\");\n        _tokenURIs[tokenId] = uri;\n    }\n\n    /**\n     * @dev Internal function to burn a specific token.\n     * Reverts if the token does not exist.\n     * Deprecated, use _burn(uint256) instead.\n     * @param owner owner of the token to burn\n     * @param tokenId uint256 ID of the token being burned by the msg.sender\n     */\n    function _burn(address owner, uint256 tokenId) internal {\n        super._burn(owner, tokenId);\n\n        // Clear metadata (if any)\n        if (bytes(_tokenURIs[tokenId]).length != 0) {\n            delete _tokenURIs[tokenId];\n        }\n    }\n}\n\n// File: @openzeppelin/contracts/token/ERC721/ERC721Full.sol\n\npragma solidity ^0.5.0;\n\n\n\n\n/**\n * @title Full ERC721 Token\n * This implementation includes all the required and some optional functionality of the ERC721 standard\n * Moreover, it includes approve all functionality using operator terminology\n * @dev see https://eips.ethereum.org/EIPS/eip-721\n */\ncontract ERC721Full is ERC721, ERC721Enumerable, ERC721Metadata {\n    constructor (string memory name, string memory symbol) public ERC721Metadata(name, symbol) {\n        // solhint-disable-previous-line no-empty-blocks\n    }\n}\n",
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+                          "typeIdentifier": "t_address_payable",
+                          "typeString": "address payable"
+                        },
+                        {
+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        },
+                        {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      ],
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+                      "name": "Transfer",
+                      "nodeType": "Identifier",
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+                      "src": "21063:8:1",
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+                    "isConstant": false,
+                    "isLValue": false,
+                    "isPure": false,
+                    "kind": "functionCall",
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+                    "names": [],
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+                    "src": "21063:33:1",
+                    "typeDescriptions": {
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+                      "typeString": "tuple()"
+                    }
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+                  "id": 766,
+                  "nodeType": "EmitStatement",
+                  "src": "21058:38:1"
+                }
+              ]
+            },
+            "documentation": "@dev Internal function to mint a new token.\nReverts if the given token ID already exists.\n@param to The address that will own the minted token\n@param tokenId uint256 ID of the token to be minted",
+            "id": 768,
+            "implemented": true,
+            "kind": "function",
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+            "name": "_mint",
+            "nodeType": "FunctionDefinition",
+            "parameters": {
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+              "nodeType": "ParameterList",
+              "parameters": [
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+                  "id": 725,
+                  "name": "to",
+                  "nodeType": "VariableDeclaration",
+                  "scope": 768,
+                  "src": "20791:10:1",
+                  "stateVariable": false,
+                  "storageLocation": "default",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_address",
+                    "typeString": "address"
+                  },
+                  "typeName": {
+                    "id": 724,
+                    "name": "address",
+                    "nodeType": "ElementaryTypeName",
+                    "src": "20791:7:1",
+                    "stateMutability": "nonpayable",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_address",
+                      "typeString": "address"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                },
+                {
+                  "constant": false,
+                  "id": 727,
+                  "name": "tokenId",
+                  "nodeType": "VariableDeclaration",
+                  "scope": 768,
+                  "src": "20803:15:1",
+                  "stateVariable": false,
+                  "storageLocation": "default",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_uint256",
+                    "typeString": "uint256"
+                  },
+                  "typeName": {
+                    "id": 726,
+                    "name": "uint256",
+                    "nodeType": "ElementaryTypeName",
+                    "src": "20803:7:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_uint256",
+                      "typeString": "uint256"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                }
+              ],
+              "src": "20790:29:1"
+            },
+            "returnParameters": {
+              "id": 729,
+              "nodeType": "ParameterList",
+              "parameters": [],
+              "src": "20829:0:1"
+            },
+            "scope": 944,
+            "src": "20776:327:1",
+            "stateMutability": "nonpayable",
+            "superFunction": null,
+            "visibility": "internal"
+          },
+          {
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+              "id": 810,
+              "nodeType": "Block",
+              "src": "21434:268:1",
+              "statements": [
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+                    "argumentTypes": null,
+                    "arguments": [
+                      {
+                        "argumentTypes": null,
+                        "commonType": {
+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        },
+                        "id": 780,
+                        "isConstant": false,
+                        "isLValue": false,
+                        "isPure": false,
+                        "lValueRequested": false,
+                        "leftExpression": {
+                          "argumentTypes": null,
+                          "arguments": [
+                            {
+                              "argumentTypes": null,
+                              "id": 777,
+                              "name": "tokenId",
+                              "nodeType": "Identifier",
+                              "overloadedDeclarations": [],
+                              "referencedDeclaration": 772,
+                              "src": "21460:7:1",
+                              "typeDescriptions": {
+                                "typeIdentifier": "t_uint256",
+                                "typeString": "uint256"
+                              }
+                            }
+                          ],
+                          "expression": {
+                            "argumentTypes": [
+                              {
+                                "typeIdentifier": "t_uint256",
+                                "typeString": "uint256"
+                              }
+                            ],
+                            "id": 776,
+                            "name": "ownerOf",
+                            "nodeType": "Identifier",
+                            "overloadedDeclarations": [
+                              480
+                            ],
+                            "referencedDeclaration": 480,
+                            "src": "21452:7:1",
+                            "typeDescriptions": {
+                              "typeIdentifier": "t_function_internal_view$_t_uint256_$returns$_t_address_$",
+                              "typeString": "function (uint256) view returns (address)"
+                            }
+                          },
+                          "id": 778,
+                          "isConstant": false,
+                          "isLValue": false,
+                          "isPure": false,
+                          "kind": "functionCall",
+                          "lValueRequested": false,
+                          "names": [],
+                          "nodeType": "FunctionCall",
+                          "src": "21452:16:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_address",
+                            "typeString": "address"
+                          }
+                        },
+                        "nodeType": "BinaryOperation",
+                        "operator": "==",
+                        "rightExpression": {
+                          "argumentTypes": null,
+                          "id": 779,
+                          "name": "owner",
+                          "nodeType": "Identifier",
+                          "overloadedDeclarations": [],
+                          "referencedDeclaration": 770,
+                          "src": "21472:5:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_address",
+                            "typeString": "address"
+                          }
+                        },
+                        "src": "21452:25:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_bool",
+                          "typeString": "bool"
+                        }
+                      },
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+                        "argumentTypes": null,
+                        "hexValue": "4552433732313a206275726e206f6620746f6b656e2074686174206973206e6f74206f776e",
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+                        "isConstant": false,
+                        "isLValue": false,
+                        "isPure": true,
+                        "kind": "string",
+                        "lValueRequested": false,
+                        "nodeType": "Literal",
+                        "src": "21479:39:1",
+                        "subdenomination": null,
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_stringliteral_d9af5b321f427d3820b5fc07b432b1ddf1bb6411d5d926d9de9773fd616ab5ee",
+                          "typeString": "literal_string \"ERC721: burn of token that is not own\""
+                        },
+                        "value": "ERC721: burn of token that is not own"
+                      }
+                    ],
+                    "expression": {
+                      "argumentTypes": [
+                        {
+                          "typeIdentifier": "t_bool",
+                          "typeString": "bool"
+                        },
+                        {
+                          "typeIdentifier": "t_stringliteral_d9af5b321f427d3820b5fc07b432b1ddf1bb6411d5d926d9de9773fd616ab5ee",
+                          "typeString": "literal_string \"ERC721: burn of token that is not own\""
+                        }
+                      ],
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+                      "name": "require",
+                      "nodeType": "Identifier",
+                      "overloadedDeclarations": [
+                        1543,
+                        1544
+                      ],
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+                      "src": "21444:7:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_function_require_pure$_t_bool_$_t_string_memory_ptr_$returns$__$",
+                        "typeString": "function (bool,string memory) pure"
+                      }
+                    },
+                    "id": 782,
+                    "isConstant": false,
+                    "isLValue": false,
+                    "isPure": false,
+                    "kind": "functionCall",
+                    "lValueRequested": false,
+                    "names": [],
+                    "nodeType": "FunctionCall",
+                    "src": "21444:75:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_tuple$__$",
+                      "typeString": "tuple()"
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+                  },
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+                  "nodeType": "ExpressionStatement",
+                  "src": "21444:75:1"
+                },
+                {
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+                    "arguments": [
+                      {
+                        "argumentTypes": null,
+                        "id": 785,
+                        "name": "tokenId",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 772,
+                        "src": "21545:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      }
+                    ],
+                    "expression": {
+                      "argumentTypes": [
+                        {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      ],
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+                      "name": "_clearApproval",
+                      "nodeType": "Identifier",
+                      "overloadedDeclarations": [],
+                      "referencedDeclaration": 943,
+                      "src": "21530:14:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_function_internal_nonpayable$_t_uint256_$returns$__$",
+                        "typeString": "function (uint256)"
+                      }
+                    },
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+                    "isConstant": false,
+                    "isLValue": false,
+                    "isPure": false,
+                    "kind": "functionCall",
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+                      "typeString": "tuple()"
+                    }
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+                  "nodeType": "ExpressionStatement",
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+                },
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+                        "baseExpression": {
+                          "argumentTypes": null,
+                          "id": 788,
+                          "name": "_ownedTokensCount",
+                          "nodeType": "Identifier",
+                          "overloadedDeclarations": [],
+                          "referencedDeclaration": 415,
+                          "src": "21564:17:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_mapping$_t_address_$_t_struct$_Counter_$296_storage_$",
+                            "typeString": "mapping(address => struct Counters.Counter storage ref)"
+                          }
+                        },
+                        "id": 790,
+                        "indexExpression": {
+                          "argumentTypes": null,
+                          "id": 789,
+                          "name": "owner",
+                          "nodeType": "Identifier",
+                          "overloadedDeclarations": [],
+                          "referencedDeclaration": 770,
+                          "src": "21582:5:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_address",
+                            "typeString": "address"
+                          }
+                        },
+                        "isConstant": false,
+                        "isLValue": true,
+                        "isPure": false,
+                        "lValueRequested": false,
+                        "nodeType": "IndexAccess",
+                        "src": "21564:24:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_struct$_Counter_$296_storage",
+                          "typeString": "struct Counters.Counter storage ref"
+                        }
+                      },
+                      "id": 791,
+                      "isConstant": false,
+                      "isLValue": true,
+                      "isPure": false,
+                      "lValueRequested": false,
+                      "memberName": "decrement",
+                      "nodeType": "MemberAccess",
+                      "referencedDeclaration": 335,
+                      "src": "21564:34:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_function_internal_nonpayable$_t_struct$_Counter_$296_storage_ptr_$returns$__$bound_to$_t_struct$_Counter_$296_storage_ptr_$",
+                        "typeString": "function (struct Counters.Counter storage pointer)"
+                      }
+                    },
+                    "id": 792,
+                    "isConstant": false,
+                    "isLValue": false,
+                    "isPure": false,
+                    "kind": "functionCall",
+                    "lValueRequested": false,
+                    "names": [],
+                    "nodeType": "FunctionCall",
+                    "src": "21564:36:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_tuple$__$",
+                      "typeString": "tuple()"
+                    }
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+                  "id": 793,
+                  "nodeType": "ExpressionStatement",
+                  "src": "21564:36:1"
+                },
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+                    "id": 800,
+                    "isConstant": false,
+                    "isLValue": false,
+                    "isPure": false,
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+                    "leftHandSide": {
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+                      "baseExpression": {
+                        "argumentTypes": null,
+                        "id": 794,
+                        "name": "_tokenOwner",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 407,
+                        "src": "21610:11:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_mapping$_t_uint256_$_t_address_$",
+                          "typeString": "mapping(uint256 => address)"
+                        }
+                      },
+                      "id": 796,
+                      "indexExpression": {
+                        "argumentTypes": null,
+                        "id": 795,
+                        "name": "tokenId",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 772,
+                        "src": "21622:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      },
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+                      "isLValue": true,
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+                      "nodeType": "IndexAccess",
+                      "src": "21610:20:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_address",
+                        "typeString": "address"
+                      }
+                    },
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+                    "operator": "=",
+                    "rightHandSide": {
+                      "argumentTypes": null,
+                      "arguments": [
+                        {
+                          "argumentTypes": null,
+                          "hexValue": "30",
+                          "id": 798,
+                          "isConstant": false,
+                          "isLValue": false,
+                          "isPure": true,
+                          "kind": "number",
+                          "lValueRequested": false,
+                          "nodeType": "Literal",
+                          "src": "21641:1:1",
+                          "subdenomination": null,
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_rational_0_by_1",
+                            "typeString": "int_const 0"
+                          },
+                          "value": "0"
+                        }
+                      ],
+                      "expression": {
+                        "argumentTypes": [
+                          {
+                            "typeIdentifier": "t_rational_0_by_1",
+                            "typeString": "int_const 0"
+                          }
+                        ],
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+                        "isConstant": false,
+                        "isLValue": false,
+                        "isPure": true,
+                        "lValueRequested": false,
+                        "nodeType": "ElementaryTypeNameExpression",
+                        "src": "21633:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_type$_t_address_$",
+                          "typeString": "type(address)"
+                        },
+                        "typeName": "address"
+                      },
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+                      "isConstant": false,
+                      "isLValue": false,
+                      "isPure": true,
+                      "kind": "typeConversion",
+                      "lValueRequested": false,
+                      "names": [],
+                      "nodeType": "FunctionCall",
+                      "src": "21633:10:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_address_payable",
+                        "typeString": "address payable"
+                      }
+                    },
+                    "src": "21610:33:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_address",
+                      "typeString": "address"
+                    }
+                  },
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+                  "nodeType": "ExpressionStatement",
+                  "src": "21610:33:1"
+                },
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+                    "arguments": [
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+                        "argumentTypes": null,
+                        "id": 803,
+                        "name": "owner",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 770,
+                        "src": "21668:5:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        }
+                      },
+                      {
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+                        "arguments": [
+                          {
+                            "argumentTypes": null,
+                            "hexValue": "30",
+                            "id": 805,
+                            "isConstant": false,
+                            "isLValue": false,
+                            "isPure": true,
+                            "kind": "number",
+                            "lValueRequested": false,
+                            "nodeType": "Literal",
+                            "src": "21683:1:1",
+                            "subdenomination": null,
+                            "typeDescriptions": {
+                              "typeIdentifier": "t_rational_0_by_1",
+                              "typeString": "int_const 0"
+                            },
+                            "value": "0"
+                          }
+                        ],
+                        "expression": {
+                          "argumentTypes": [
+                            {
+                              "typeIdentifier": "t_rational_0_by_1",
+                              "typeString": "int_const 0"
+                            }
+                          ],
+                          "id": 804,
+                          "isConstant": false,
+                          "isLValue": false,
+                          "isPure": true,
+                          "lValueRequested": false,
+                          "nodeType": "ElementaryTypeNameExpression",
+                          "src": "21675:7:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_type$_t_address_$",
+                            "typeString": "type(address)"
+                          },
+                          "typeName": "address"
+                        },
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+                        "isConstant": false,
+                        "isLValue": false,
+                        "isPure": true,
+                        "kind": "typeConversion",
+                        "lValueRequested": false,
+                        "names": [],
+                        "nodeType": "FunctionCall",
+                        "src": "21675:10:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_address_payable",
+                          "typeString": "address payable"
+                        }
+                      },
+                      {
+                        "argumentTypes": null,
+                        "id": 807,
+                        "name": "tokenId",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 772,
+                        "src": "21687:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      }
+                    ],
+                    "expression": {
+                      "argumentTypes": [
+                        {
+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        },
+                        {
+                          "typeIdentifier": "t_address_payable",
+                          "typeString": "address payable"
+                        },
+                        {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      ],
+                      "id": 802,
+                      "name": "Transfer",
+                      "nodeType": "Identifier",
+                      "overloadedDeclarations": [],
+                      "referencedDeclaration": 34,
+                      "src": "21659:8:1",
+                      "typeDescriptions": {
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+                        "typeString": "function (address,address,uint256)"
+                      }
+                    },
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+                    "isLValue": false,
+                    "isPure": false,
+                    "kind": "functionCall",
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+                    "nodeType": "FunctionCall",
+                    "src": "21659:36:1",
+                    "typeDescriptions": {
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+                      "typeString": "tuple()"
+                    }
+                  },
+                  "id": 809,
+                  "nodeType": "EmitStatement",
+                  "src": "21654:41:1"
+                }
+              ]
+            },
+            "documentation": "@dev Internal function to burn a specific token.\nReverts if the token does not exist.\nDeprecated, use _burn(uint256) instead.\n@param owner owner of the token to burn\n@param tokenId uint256 ID of the token being burned",
+            "id": 811,
+            "implemented": true,
+            "kind": "function",
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+              "nodeType": "ParameterList",
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+                  "id": 770,
+                  "name": "owner",
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+                  "scope": 811,
+                  "src": "21393:13:1",
+                  "stateVariable": false,
+                  "storageLocation": "default",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_address",
+                    "typeString": "address"
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+                  "typeName": {
+                    "id": 769,
+                    "name": "address",
+                    "nodeType": "ElementaryTypeName",
+                    "src": "21393:7:1",
+                    "stateMutability": "nonpayable",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_address",
+                      "typeString": "address"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                },
+                {
+                  "constant": false,
+                  "id": 772,
+                  "name": "tokenId",
+                  "nodeType": "VariableDeclaration",
+                  "scope": 811,
+                  "src": "21408:15:1",
+                  "stateVariable": false,
+                  "storageLocation": "default",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_uint256",
+                    "typeString": "uint256"
+                  },
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+                    "name": "uint256",
+                    "nodeType": "ElementaryTypeName",
+                    "src": "21408:7:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_uint256",
+                      "typeString": "uint256"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                }
+              ],
+              "src": "21392:32:1"
+            },
+            "returnParameters": {
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+              "nodeType": "ParameterList",
+              "parameters": [],
+              "src": "21434:0:1"
+            },
+            "scope": 944,
+            "src": "21378:324:1",
+            "stateMutability": "nonpayable",
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+            "visibility": "internal"
+          },
+          {
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+              "nodeType": "Block",
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+              "statements": [
+                {
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+                    "argumentTypes": null,
+                    "arguments": [
+                      {
+                        "argumentTypes": null,
+                        "arguments": [
+                          {
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+                          "typeString": "address"
+                        }
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+                        "typeDescriptions": {
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+                          "typeString": "address"
+                        }
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+                        "id": 876,
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+                        "src": "22780:7:1",
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+                          "typeString": "uint256"
+                        }
+                      }
+                    ],
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+                      "argumentTypes": [
+                        {
+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        },
+                        {
+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        },
+                        {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      ],
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+                      "name": "Transfer",
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+                }
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+            },
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+                      "typeString": "address"
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+                          "src": "23514:2:1",
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+                            "typeIdentifier": "t_address",
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+                          "typeIdentifier": "t_bytes4",
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+                          "name": "msg",
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+                          "src": "23630:3:1",
+                          "typeDescriptions": {
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+                            "typeString": "msg"
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+                        "src": "23630:10:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_address_payable",
+                          "typeString": "address payable"
+                        }
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+                        "name": "from",
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+                        "typeDescriptions": {
+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        }
+                      },
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+                        "name": "tokenId",
+                        "nodeType": "Identifier",
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+                        "src": "23648:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
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+                        "name": "_data",
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+                        "src": "23657:5:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_bytes_memory_ptr",
+                          "typeString": "bytes memory"
+                        }
+                      }
+                    ],
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+                      "argumentTypes": [
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+                          "typeIdentifier": "t_address_payable",
+                          "typeString": "address payable"
+                        },
+                        {
+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        },
+                        {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        },
+                        {
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+                          "typeString": "bytes memory"
+                        }
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+                            "src": "23609:2:1",
+                            "typeDescriptions": {
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+                              "typeString": "address"
+                            }
+                          }
+                        ],
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+                              "typeIdentifier": "t_address",
+                              "typeString": "address"
+                            }
+                          ],
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+                          "name": "IERC721Receiver",
+                          "nodeType": "Identifier",
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+                          "referencedDeclaration": 139,
+                          "src": "23593:15:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_type$_t_contract$_IERC721Receiver_$139_$",
+                            "typeString": "type(contract IERC721Receiver)"
+                          }
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+                        "kind": "typeConversion",
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+                          "typeIdentifier": "t_contract$_IERC721Receiver_$139",
+                          "typeString": "contract IERC721Receiver"
+                        }
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+                      }
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+                    }
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+                  "src": "23577:86:1"
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+                        "commonType": {
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+                          "typeString": "bytes4"
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+                          "src": "23681:6:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_bytes4",
+                            "typeString": "bytes4"
+                          }
+                        },
+                        "nodeType": "BinaryOperation",
+                        "operator": "==",
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+                          "argumentTypes": null,
+                          "id": 915,
+                          "name": "_ERC721_RECEIVED",
+                          "nodeType": "Identifier",
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+                          "referencedDeclaration": 403,
+                          "src": "23691:16:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_bytes4",
+                            "typeString": "bytes4"
+                          }
+                        },
+                        "src": "23681:26:1",
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+                          "typeString": "bool"
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+                  "nodeType": "Return",
+                  "src": "23673:35:1"
+                }
+              ]
+            },
+            "documentation": "@dev Internal function to invoke `onERC721Received` on a target address.\nThe call is not executed if the target address is not a contract.\n     * This function is deprecated.\n@param from address representing the previous owner of the given token ID\n@param to target address that will receive the tokens\n@param tokenId uint256 ID of the token to be transferred\n@param _data bytes optional data to send along with the call\n@return bool whether the call correctly returned the expected magic value",
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+            "kind": "function",
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+                  "storageLocation": "default",
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+                  "src": "23414:10:1",
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+                    "typeString": "address"
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+                  "src": "23443:18:1",
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+                  "storageLocation": "memory",
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+                      "typeDescriptions": {
+                        "typeIdentifier": "t_function_require_pure$_t_bool_$_t_string_memory_ptr_$returns$__$",
+                        "typeString": "function (bool,string memory) pure"
+                      }
+                    },
+                    "id": 1050,
+                    "isConstant": false,
+                    "isLValue": false,
+                    "isPure": false,
+                    "kind": "functionCall",
+                    "lValueRequested": false,
+                    "names": [],
+                    "nodeType": "FunctionCall",
+                    "src": "27171:78:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_tuple$__$",
+                      "typeString": "tuple()"
+                    }
+                  },
+                  "id": 1051,
+                  "nodeType": "ExpressionStatement",
+                  "src": "27171:78:1"
+                },
+                {
+                  "expression": {
+                    "argumentTypes": null,
+                    "baseExpression": {
+                      "argumentTypes": null,
+                      "id": 1052,
+                      "name": "_allTokens",
+                      "nodeType": "Identifier",
+                      "overloadedDeclarations": [],
+                      "referencedDeclaration": 988,
+                      "src": "27266:10:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_array$_t_uint256_$dyn_storage",
+                        "typeString": "uint256[] storage ref"
+                      }
+                    },
+                    "id": 1054,
+                    "indexExpression": {
+                      "argumentTypes": null,
+                      "id": 1053,
+                      "name": "index",
+                      "nodeType": "Identifier",
+                      "overloadedDeclarations": [],
+                      "referencedDeclaration": 1039,
+                      "src": "27277:5:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_uint256",
+                        "typeString": "uint256"
+                      }
+                    },
+                    "isConstant": false,
+                    "isLValue": true,
+                    "isPure": false,
+                    "lValueRequested": false,
+                    "nodeType": "IndexAccess",
+                    "src": "27266:17:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_uint256",
+                      "typeString": "uint256"
+                    }
+                  },
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+                  "id": 1055,
+                  "nodeType": "Return",
+                  "src": "27259:24:1"
+                }
+              ]
+            },
+            "documentation": "@dev Gets the token ID at a given index of all the tokens in this contract\nReverts if the index is greater or equal to the total number of tokens.\n@param index uint256 representing the index to be accessed of the tokens list\n@return uint256 token ID at the given index of the tokens list",
+            "id": 1057,
+            "implemented": true,
+            "kind": "function",
+            "modifiers": [],
+            "name": "tokenByIndex",
+            "nodeType": "FunctionDefinition",
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+              "id": 1040,
+              "nodeType": "ParameterList",
+              "parameters": [
+                {
+                  "constant": false,
+                  "id": 1039,
+                  "name": "index",
+                  "nodeType": "VariableDeclaration",
+                  "scope": 1057,
+                  "src": "27116:13:1",
+                  "stateVariable": false,
+                  "storageLocation": "default",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_uint256",
+                    "typeString": "uint256"
+                  },
+                  "typeName": {
+                    "id": 1038,
+                    "name": "uint256",
+                    "nodeType": "ElementaryTypeName",
+                    "src": "27116:7:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_uint256",
+                      "typeString": "uint256"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                }
+              ],
+              "src": "27115:15:1"
+            },
+            "returnParameters": {
+              "id": 1043,
+              "nodeType": "ParameterList",
+              "parameters": [
+                {
+                  "constant": false,
+                  "id": 1042,
+                  "name": "",
+                  "nodeType": "VariableDeclaration",
+                  "scope": 1057,
+                  "src": "27152:7:1",
+                  "stateVariable": false,
+                  "storageLocation": "default",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_uint256",
+                    "typeString": "uint256"
+                  },
+                  "typeName": {
+                    "id": 1041,
+                    "name": "uint256",
+                    "nodeType": "ElementaryTypeName",
+                    "src": "27152:7:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_uint256",
+                      "typeString": "uint256"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                }
+              ],
+              "src": "27151:9:1"
+            },
+            "scope": 1302,
+            "src": "27094:196:1",
+            "stateMutability": "view",
+            "superFunction": 968,
+            "visibility": "public"
+          },
+          {
+            "body": {
+              "id": 1084,
+              "nodeType": "Block",
+              "src": "27740:164:1",
+              "statements": [
+                {
+                  "expression": {
+                    "argumentTypes": null,
+                    "arguments": [
+                      {
+                        "argumentTypes": null,
+                        "id": 1069,
+                        "name": "from",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 1059,
+                        "src": "27770:4:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        }
+                      },
+                      {
+                        "argumentTypes": null,
+                        "id": 1070,
+                        "name": "to",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 1061,
+                        "src": "27776:2:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        }
+                      },
+                      {
+                        "argumentTypes": null,
+                        "id": 1071,
+                        "name": "tokenId",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 1063,
+                        "src": "27780:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      }
+                    ],
+                    "expression": {
+                      "argumentTypes": [
+                        {
+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        },
+                        {
+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        },
+                        {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      ],
+                      "expression": {
+                        "argumentTypes": null,
+                        "id": 1066,
+                        "name": "super",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 1572,
+                        "src": "27750:5:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_super$_ERC721Enumerable_$1302",
+                          "typeString": "contract super ERC721Enumerable"
+                        }
+                      },
+                      "id": 1068,
+                      "isConstant": false,
+                      "isLValue": false,
+                      "isPure": false,
+                      "lValueRequested": false,
+                      "memberName": "_transferFrom",
+                      "nodeType": "MemberAccess",
+                      "referencedDeclaration": 880,
+                      "src": "27750:19:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_function_internal_nonpayable$_t_address_$_t_address_$_t_uint256_$returns$__$",
+                        "typeString": "function (address,address,uint256)"
+                      }
+                    },
+                    "id": 1072,
+                    "isConstant": false,
+                    "isLValue": false,
+                    "isPure": false,
+                    "kind": "functionCall",
+                    "lValueRequested": false,
+                    "names": [],
+                    "nodeType": "FunctionCall",
+                    "src": "27750:38:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_tuple$__$",
+                      "typeString": "tuple()"
+                    }
+                  },
+                  "id": 1073,
+                  "nodeType": "ExpressionStatement",
+                  "src": "27750:38:1"
+                },
+                {
+                  "expression": {
+                    "argumentTypes": null,
+                    "arguments": [
+                      {
+                        "argumentTypes": null,
+                        "id": 1075,
+                        "name": "from",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 1059,
+                        "src": "27832:4:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        }
+                      },
+                      {
+                        "argumentTypes": null,
+                        "id": 1076,
+                        "name": "tokenId",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 1063,
+                        "src": "27838:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      }
+                    ],
+                    "expression": {
+                      "argumentTypes": [
+                        {
+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        },
+                        {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      ],
+                      "id": 1074,
+                      "name": "_removeTokenFromOwnerEnumeration",
+                      "nodeType": "Identifier",
+                      "overloadedDeclarations": [],
+                      "referencedDeclaration": 1252,
+                      "src": "27799:32:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_function_internal_nonpayable$_t_address_$_t_uint256_$returns$__$",
+                        "typeString": "function (address,uint256)"
+                      }
+                    },
+                    "id": 1077,
+                    "isConstant": false,
+                    "isLValue": false,
+                    "isPure": false,
+                    "kind": "functionCall",
+                    "lValueRequested": false,
+                    "names": [],
+                    "nodeType": "FunctionCall",
+                    "src": "27799:47:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_tuple$__$",
+                      "typeString": "tuple()"
+                    }
+                  },
+                  "id": 1078,
+                  "nodeType": "ExpressionStatement",
+                  "src": "27799:47:1"
+                },
+                {
+                  "expression": {
+                    "argumentTypes": null,
+                    "arguments": [
+                      {
+                        "argumentTypes": null,
+                        "id": 1080,
+                        "name": "to",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 1061,
+                        "src": "27885:2:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        }
+                      },
+                      {
+                        "argumentTypes": null,
+                        "id": 1081,
+                        "name": "tokenId",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 1063,
+                        "src": "27889:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      }
+                    ],
+                    "expression": {
+                      "argumentTypes": [
+                        {
+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        },
+                        {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      ],
+                      "id": 1079,
+                      "name": "_addTokenToOwnerEnumeration",
+                      "nodeType": "Identifier",
+                      "overloadedDeclarations": [],
+                      "referencedDeclaration": 1176,
+                      "src": "27857:27:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_function_internal_nonpayable$_t_address_$_t_uint256_$returns$__$",
+                        "typeString": "function (address,uint256)"
+                      }
+                    },
+                    "id": 1082,
+                    "isConstant": false,
+                    "isLValue": false,
+                    "isPure": false,
+                    "kind": "functionCall",
+                    "lValueRequested": false,
+                    "names": [],
+                    "nodeType": "FunctionCall",
+                    "src": "27857:40:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_tuple$__$",
+                      "typeString": "tuple()"
+                    }
+                  },
+                  "id": 1083,
+                  "nodeType": "ExpressionStatement",
+                  "src": "27857:40:1"
+                }
+              ]
+            },
+            "documentation": "@dev Internal function to transfer ownership of a given token ID to another address.\nAs opposed to transferFrom, this imposes no restrictions on msg.sender.\n@param from current owner of the token\n@param to address to receive the ownership of the given token ID\n@param tokenId uint256 ID of the token to be transferred",
+            "id": 1085,
+            "implemented": true,
+            "kind": "function",
+            "modifiers": [],
+            "name": "_transferFrom",
+            "nodeType": "FunctionDefinition",
+            "parameters": {
+              "id": 1064,
+              "nodeType": "ParameterList",
+              "parameters": [
+                {
+                  "constant": false,
+                  "id": 1059,
+                  "name": "from",
+                  "nodeType": "VariableDeclaration",
+                  "scope": 1085,
+                  "src": "27688:12:1",
+                  "stateVariable": false,
+                  "storageLocation": "default",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_address",
+                    "typeString": "address"
+                  },
+                  "typeName": {
+                    "id": 1058,
+                    "name": "address",
+                    "nodeType": "ElementaryTypeName",
+                    "src": "27688:7:1",
+                    "stateMutability": "nonpayable",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_address",
+                      "typeString": "address"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                },
+                {
+                  "constant": false,
+                  "id": 1061,
+                  "name": "to",
+                  "nodeType": "VariableDeclaration",
+                  "scope": 1085,
+                  "src": "27702:10:1",
+                  "stateVariable": false,
+                  "storageLocation": "default",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_address",
+                    "typeString": "address"
+                  },
+                  "typeName": {
+                    "id": 1060,
+                    "name": "address",
+                    "nodeType": "ElementaryTypeName",
+                    "src": "27702:7:1",
+                    "stateMutability": "nonpayable",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_address",
+                      "typeString": "address"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                },
+                {
+                  "constant": false,
+                  "id": 1063,
+                  "name": "tokenId",
+                  "nodeType": "VariableDeclaration",
+                  "scope": 1085,
+                  "src": "27714:15:1",
+                  "stateVariable": false,
+                  "storageLocation": "default",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_uint256",
+                    "typeString": "uint256"
+                  },
+                  "typeName": {
+                    "id": 1062,
+                    "name": "uint256",
+                    "nodeType": "ElementaryTypeName",
+                    "src": "27714:7:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_uint256",
+                      "typeString": "uint256"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                }
+              ],
+              "src": "27687:43:1"
+            },
+            "returnParameters": {
+              "id": 1065,
+              "nodeType": "ParameterList",
+              "parameters": [],
+              "src": "27740:0:1"
+            },
+            "scope": 1302,
+            "src": "27665:239:1",
+            "stateMutability": "nonpayable",
+            "superFunction": 880,
+            "visibility": "internal"
+          },
+          {
+            "body": {
+              "id": 1108,
+              "nodeType": "Block",
+              "src": "28214:143:1",
+              "statements": [
+                {
+                  "expression": {
+                    "argumentTypes": null,
+                    "arguments": [
+                      {
+                        "argumentTypes": null,
+                        "id": 1095,
+                        "name": "to",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 1087,
+                        "src": "28236:2:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        }
+                      },
+                      {
+                        "argumentTypes": null,
+                        "id": 1096,
+                        "name": "tokenId",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 1089,
+                        "src": "28240:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      }
+                    ],
+                    "expression": {
+                      "argumentTypes": [
+                        {
+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        },
+                        {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      ],
+                      "expression": {
+                        "argumentTypes": null,
+                        "id": 1092,
+                        "name": "super",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 1572,
+                        "src": "28224:5:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_super$_ERC721Enumerable_$1302",
+                          "typeString": "contract super ERC721Enumerable"
+                        }
+                      },
+                      "id": 1094,
+                      "isConstant": false,
+                      "isLValue": false,
+                      "isPure": false,
+                      "lValueRequested": false,
+                      "memberName": "_mint",
+                      "nodeType": "MemberAccess",
+                      "referencedDeclaration": 768,
+                      "src": "28224:11:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_function_internal_nonpayable$_t_address_$_t_uint256_$returns$__$",
+                        "typeString": "function (address,uint256)"
+                      }
+                    },
+                    "id": 1097,
+                    "isConstant": false,
+                    "isLValue": false,
+                    "isPure": false,
+                    "kind": "functionCall",
+                    "lValueRequested": false,
+                    "names": [],
+                    "nodeType": "FunctionCall",
+                    "src": "28224:24:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_tuple$__$",
+                      "typeString": "tuple()"
+                    }
+                  },
+                  "id": 1098,
+                  "nodeType": "ExpressionStatement",
+                  "src": "28224:24:1"
+                },
+                {
+                  "expression": {
+                    "argumentTypes": null,
+                    "arguments": [
+                      {
+                        "argumentTypes": null,
+                        "id": 1100,
+                        "name": "to",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 1087,
+                        "src": "28287:2:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        }
+                      },
+                      {
+                        "argumentTypes": null,
+                        "id": 1101,
+                        "name": "tokenId",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 1089,
+                        "src": "28291:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      }
+                    ],
+                    "expression": {
+                      "argumentTypes": [
+                        {
+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        },
+                        {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      ],
+                      "id": 1099,
+                      "name": "_addTokenToOwnerEnumeration",
+                      "nodeType": "Identifier",
+                      "overloadedDeclarations": [],
+                      "referencedDeclaration": 1176,
+                      "src": "28259:27:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_function_internal_nonpayable$_t_address_$_t_uint256_$returns$__$",
+                        "typeString": "function (address,uint256)"
+                      }
+                    },
+                    "id": 1102,
+                    "isConstant": false,
+                    "isLValue": false,
+                    "isPure": false,
+                    "kind": "functionCall",
+                    "lValueRequested": false,
+                    "names": [],
+                    "nodeType": "FunctionCall",
+                    "src": "28259:40:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_tuple$__$",
+                      "typeString": "tuple()"
+                    }
+                  },
+                  "id": 1103,
+                  "nodeType": "ExpressionStatement",
+                  "src": "28259:40:1"
+                },
+                {
+                  "expression": {
+                    "argumentTypes": null,
+                    "arguments": [
+                      {
+                        "argumentTypes": null,
+                        "id": 1105,
+                        "name": "tokenId",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 1089,
+                        "src": "28342:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      }
+                    ],
+                    "expression": {
+                      "argumentTypes": [
+                        {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      ],
+                      "id": 1104,
+                      "name": "_addTokenToAllTokensEnumeration",
+                      "nodeType": "Identifier",
+                      "overloadedDeclarations": [],
+                      "referencedDeclaration": 1195,
+                      "src": "28310:31:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_function_internal_nonpayable$_t_uint256_$returns$__$",
+                        "typeString": "function (uint256)"
+                      }
+                    },
+                    "id": 1106,
+                    "isConstant": false,
+                    "isLValue": false,
+                    "isPure": false,
+                    "kind": "functionCall",
+                    "lValueRequested": false,
+                    "names": [],
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+                    "src": "28310:40:1",
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+                      "typeIdentifier": "t_tuple$__$",
+                      "typeString": "tuple()"
+                    }
+                  },
+                  "id": 1107,
+                  "nodeType": "ExpressionStatement",
+                  "src": "28310:40:1"
+                }
+              ]
+            },
+            "documentation": "@dev Internal function to mint a new token.\nReverts if the given token ID already exists.\n@param to address the beneficiary that will own the minted token\n@param tokenId uint256 ID of the token to be minted",
+            "id": 1109,
+            "implemented": true,
+            "kind": "function",
+            "modifiers": [],
+            "name": "_mint",
+            "nodeType": "FunctionDefinition",
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+              "parameters": [
+                {
+                  "constant": false,
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+                  "name": "to",
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+                  "scope": 1109,
+                  "src": "28176:10:1",
+                  "stateVariable": false,
+                  "storageLocation": "default",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_address",
+                    "typeString": "address"
+                  },
+                  "typeName": {
+                    "id": 1086,
+                    "name": "address",
+                    "nodeType": "ElementaryTypeName",
+                    "src": "28176:7:1",
+                    "stateMutability": "nonpayable",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_address",
+                      "typeString": "address"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                },
+                {
+                  "constant": false,
+                  "id": 1089,
+                  "name": "tokenId",
+                  "nodeType": "VariableDeclaration",
+                  "scope": 1109,
+                  "src": "28188:15:1",
+                  "stateVariable": false,
+                  "storageLocation": "default",
+                  "typeDescriptions": {
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+                      "typeString": "uint256"
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+            "visibility": "internal"
+          },
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+                        "src": "28710:5:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        }
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+                        "name": "tokenId",
+                        "nodeType": "Identifier",
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+                        "src": "28717:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
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+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        },
+                        {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
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+                        "src": "28698:5:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_super$_ERC721Enumerable_$1302",
+                          "typeString": "contract super ERC721Enumerable"
+                        }
+                      },
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+                      "isConstant": false,
+                      "isLValue": false,
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+                      "src": "28698:11:1",
+                      "typeDescriptions": {
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+                      }
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+                        "src": "28769:5:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        }
+                      },
+                      {
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+                        "id": 1125,
+                        "name": "tokenId",
+                        "nodeType": "Identifier",
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+                        "src": "28776:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      }
+                    ],
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+                      "argumentTypes": [
+                        {
+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        },
+                        {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      ],
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+                      "name": "_removeTokenFromOwnerEnumeration",
+                      "nodeType": "Identifier",
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+                      "src": "28736:32:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_function_internal_nonpayable$_t_address_$_t_uint256_$returns$__$",
+                        "typeString": "function (address,uint256)"
+                      }
+                    },
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+                    "isLValue": false,
+                    "isPure": false,
+                    "kind": "functionCall",
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+                    "nodeType": "FunctionCall",
+                    "src": "28736:48:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_tuple$__$",
+                      "typeString": "tuple()"
+                    }
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+                  "id": 1127,
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+                  "src": "28736:48:1"
+                },
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+                    "lValueRequested": false,
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+                      "baseExpression": {
+                        "argumentTypes": null,
+                        "id": 1128,
+                        "name": "_ownedTokensIndex",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 985,
+                        "src": "28903:17:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_mapping$_t_uint256_$_t_uint256_$",
+                          "typeString": "mapping(uint256 => uint256)"
+                        }
+                      },
+                      "id": 1130,
+                      "indexExpression": {
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+                        "id": 1129,
+                        "name": "tokenId",
+                        "nodeType": "Identifier",
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+                        "referencedDeclaration": 1113,
+                        "src": "28921:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      },
+                      "isConstant": false,
+                      "isLValue": true,
+                      "isPure": false,
+                      "lValueRequested": true,
+                      "nodeType": "IndexAccess",
+                      "src": "28903:26:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_uint256",
+                        "typeString": "uint256"
+                      }
+                    },
+                    "nodeType": "Assignment",
+                    "operator": "=",
+                    "rightHandSide": {
+                      "argumentTypes": null,
+                      "hexValue": "30",
+                      "id": 1131,
+                      "isConstant": false,
+                      "isLValue": false,
+                      "isPure": true,
+                      "kind": "number",
+                      "lValueRequested": false,
+                      "nodeType": "Literal",
+                      "src": "28932:1:1",
+                      "subdenomination": null,
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_rational_0_by_1",
+                        "typeString": "int_const 0"
+                      },
+                      "value": "0"
+                    },
+                    "src": "28903:30:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_uint256",
+                      "typeString": "uint256"
+                    }
+                  },
+                  "id": 1133,
+                  "nodeType": "ExpressionStatement",
+                  "src": "28903:30:1"
+                },
+                {
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+                    "argumentTypes": null,
+                    "arguments": [
+                      {
+                        "argumentTypes": null,
+                        "id": 1135,
+                        "name": "tokenId",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 1113,
+                        "src": "28981:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      }
+                    ],
+                    "expression": {
+                      "argumentTypes": [
+                        {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      ],
+                      "id": 1134,
+                      "name": "_removeTokenFromAllTokensEnumeration",
+                      "nodeType": "Identifier",
+                      "overloadedDeclarations": [],
+                      "referencedDeclaration": 1301,
+                      "src": "28944:36:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_function_internal_nonpayable$_t_uint256_$returns$__$",
+                        "typeString": "function (uint256)"
+                      }
+                    },
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+                    "isConstant": false,
+                    "isLValue": false,
+                    "isPure": false,
+                    "kind": "functionCall",
+                    "lValueRequested": false,
+                    "names": [],
+                    "nodeType": "FunctionCall",
+                    "src": "28944:45:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_tuple$__$",
+                      "typeString": "tuple()"
+                    }
+                  },
+                  "id": 1137,
+                  "nodeType": "ExpressionStatement",
+                  "src": "28944:45:1"
+                }
+              ]
+            },
+            "documentation": "@dev Internal function to burn a specific token.\nReverts if the token does not exist.\nDeprecated, use _burn(uint256) instead.\n@param owner owner of the token to burn\n@param tokenId uint256 ID of the token being burned",
+            "id": 1139,
+            "implemented": true,
+            "kind": "function",
+            "modifiers": [],
+            "name": "_burn",
+            "nodeType": "FunctionDefinition",
+            "parameters": {
+              "id": 1114,
+              "nodeType": "ParameterList",
+              "parameters": [
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+                  "id": 1111,
+                  "name": "owner",
+                  "nodeType": "VariableDeclaration",
+                  "scope": 1139,
+                  "src": "28647:13:1",
+                  "stateVariable": false,
+                  "storageLocation": "default",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_address",
+                    "typeString": "address"
+                  },
+                  "typeName": {
+                    "id": 1110,
+                    "name": "address",
+                    "nodeType": "ElementaryTypeName",
+                    "src": "28647:7:1",
+                    "stateMutability": "nonpayable",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_address",
+                      "typeString": "address"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                },
+                {
+                  "constant": false,
+                  "id": 1113,
+                  "name": "tokenId",
+                  "nodeType": "VariableDeclaration",
+                  "scope": 1139,
+                  "src": "28662:15:1",
+                  "stateVariable": false,
+                  "storageLocation": "default",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_uint256",
+                    "typeString": "uint256"
+                  },
+                  "typeName": {
+                    "id": 1112,
+                    "name": "uint256",
+                    "nodeType": "ElementaryTypeName",
+                    "src": "28662:7:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_uint256",
+                      "typeString": "uint256"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                }
+              ],
+              "src": "28646:32:1"
+            },
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+              "id": 1115,
+              "nodeType": "ParameterList",
+              "parameters": [],
+              "src": "28688:0:1"
+            },
+            "scope": 1302,
+            "src": "28632:364:1",
+            "stateMutability": "nonpayable",
+            "superFunction": 811,
+            "visibility": "internal"
+          },
+          {
+            "body": {
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+              "nodeType": "Block",
+              "src": "29282:43:1",
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+                    "baseExpression": {
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+                      "id": 1147,
+                      "name": "_ownedTokens",
+                      "nodeType": "Identifier",
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+                      "referencedDeclaration": 981,
+                      "src": "29299:12:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_mapping$_t_address_$_t_array$_t_uint256_$dyn_storage_$",
+                        "typeString": "mapping(address => uint256[] storage ref)"
+                      }
+                    },
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+                      "id": 1148,
+                      "name": "owner",
+                      "nodeType": "Identifier",
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+                      "referencedDeclaration": 1141,
+                      "src": "29312:5:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_address",
+                        "typeString": "address"
+                      }
+                    },
+                    "isConstant": false,
+                    "isLValue": true,
+                    "isPure": false,
+                    "lValueRequested": false,
+                    "nodeType": "IndexAccess",
+                    "src": "29299:19:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_array$_t_uint256_$dyn_storage",
+                      "typeString": "uint256[] storage ref"
+                    }
+                  },
+                  "functionReturnParameters": 1146,
+                  "id": 1150,
+                  "nodeType": "Return",
+                  "src": "29292:26:1"
+                }
+              ]
+            },
+            "documentation": "@dev Gets the list of token IDs of the requested owner.\n@param owner address owning the tokens\n@return uint256[] List of token IDs owned by the requested address",
+            "id": 1152,
+            "implemented": true,
+            "kind": "function",
+            "modifiers": [],
+            "name": "_tokensOfOwner",
+            "nodeType": "FunctionDefinition",
+            "parameters": {
+              "id": 1142,
+              "nodeType": "ParameterList",
+              "parameters": [
+                {
+                  "constant": false,
+                  "id": 1141,
+                  "name": "owner",
+                  "nodeType": "VariableDeclaration",
+                  "scope": 1152,
+                  "src": "29225:13:1",
+                  "stateVariable": false,
+                  "storageLocation": "default",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_address",
+                    "typeString": "address"
+                  },
+                  "typeName": {
+                    "id": 1140,
+                    "name": "address",
+                    "nodeType": "ElementaryTypeName",
+                    "src": "29225:7:1",
+                    "stateMutability": "nonpayable",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_address",
+                      "typeString": "address"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                }
+              ],
+              "src": "29224:15:1"
+            },
+            "returnParameters": {
+              "id": 1146,
+              "nodeType": "ParameterList",
+              "parameters": [
+                {
+                  "constant": false,
+                  "id": 1145,
+                  "name": "",
+                  "nodeType": "VariableDeclaration",
+                  "scope": 1152,
+                  "src": "29263:17:1",
+                  "stateVariable": false,
+                  "storageLocation": "storage",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_array$_t_uint256_$dyn_storage_ptr",
+                    "typeString": "uint256[]"
+                  },
+                  "typeName": {
+                    "baseType": {
+                      "id": 1143,
+                      "name": "uint256",
+                      "nodeType": "ElementaryTypeName",
+                      "src": "29263:7:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_uint256",
+                        "typeString": "uint256"
+                      }
+                    },
+                    "id": 1144,
+                    "length": null,
+                    "nodeType": "ArrayTypeName",
+                    "src": "29263:9:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_array$_t_uint256_$dyn_storage_ptr",
+                      "typeString": "uint256[]"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                }
+              ],
+              "src": "29262:19:1"
+            },
+            "scope": 1302,
+            "src": "29201:124:1",
+            "stateMutability": "view",
+            "superFunction": null,
+            "visibility": "internal"
+          },
+          {
+            "body": {
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+              "nodeType": "Block",
+              "src": "29693:109:1",
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+                        "id": 1159,
+                        "name": "_ownedTokensIndex",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 985,
+                        "src": "29703:17:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_mapping$_t_uint256_$_t_uint256_$",
+                          "typeString": "mapping(uint256 => uint256)"
+                        }
+                      },
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+                        "id": 1160,
+                        "name": "tokenId",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 1156,
+                        "src": "29721:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
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+                      "lValueRequested": true,
+                      "nodeType": "IndexAccess",
+                      "src": "29703:26:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_uint256",
+                        "typeString": "uint256"
+                      }
+                    },
+                    "nodeType": "Assignment",
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+                      "expression": {
+                        "argumentTypes": null,
+                        "baseExpression": {
+                          "argumentTypes": null,
+                          "id": 1162,
+                          "name": "_ownedTokens",
+                          "nodeType": "Identifier",
+                          "overloadedDeclarations": [],
+                          "referencedDeclaration": 981,
+                          "src": "29732:12:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_mapping$_t_address_$_t_array$_t_uint256_$dyn_storage_$",
+                            "typeString": "mapping(address => uint256[] storage ref)"
+                          }
+                        },
+                        "id": 1164,
+                        "indexExpression": {
+                          "argumentTypes": null,
+                          "id": 1163,
+                          "name": "to",
+                          "nodeType": "Identifier",
+                          "overloadedDeclarations": [],
+                          "referencedDeclaration": 1154,
+                          "src": "29745:2:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_address",
+                            "typeString": "address"
+                          }
+                        },
+                        "isConstant": false,
+                        "isLValue": true,
+                        "isPure": false,
+                        "lValueRequested": false,
+                        "nodeType": "IndexAccess",
+                        "src": "29732:16:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_array$_t_uint256_$dyn_storage",
+                          "typeString": "uint256[] storage ref"
+                        }
+                      },
+                      "id": 1165,
+                      "isConstant": false,
+                      "isLValue": true,
+                      "isPure": false,
+                      "lValueRequested": false,
+                      "memberName": "length",
+                      "nodeType": "MemberAccess",
+                      "referencedDeclaration": null,
+                      "src": "29732:23:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_uint256",
+                        "typeString": "uint256"
+                      }
+                    },
+                    "src": "29703:52:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_uint256",
+                      "typeString": "uint256"
+                    }
+                  },
+                  "id": 1167,
+                  "nodeType": "ExpressionStatement",
+                  "src": "29703:52:1"
+                },
+                {
+                  "expression": {
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+                    "arguments": [
+                      {
+                        "argumentTypes": null,
+                        "id": 1172,
+                        "name": "tokenId",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 1156,
+                        "src": "29787:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      }
+                    ],
+                    "expression": {
+                      "argumentTypes": [
+                        {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      ],
+                      "expression": {
+                        "argumentTypes": null,
+                        "baseExpression": {
+                          "argumentTypes": null,
+                          "id": 1168,
+                          "name": "_ownedTokens",
+                          "nodeType": "Identifier",
+                          "overloadedDeclarations": [],
+                          "referencedDeclaration": 981,
+                          "src": "29765:12:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_mapping$_t_address_$_t_array$_t_uint256_$dyn_storage_$",
+                            "typeString": "mapping(address => uint256[] storage ref)"
+                          }
+                        },
+                        "id": 1170,
+                        "indexExpression": {
+                          "argumentTypes": null,
+                          "id": 1169,
+                          "name": "to",
+                          "nodeType": "Identifier",
+                          "overloadedDeclarations": [],
+                          "referencedDeclaration": 1154,
+                          "src": "29778:2:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_address",
+                            "typeString": "address"
+                          }
+                        },
+                        "isConstant": false,
+                        "isLValue": true,
+                        "isPure": false,
+                        "lValueRequested": false,
+                        "nodeType": "IndexAccess",
+                        "src": "29765:16:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_array$_t_uint256_$dyn_storage",
+                          "typeString": "uint256[] storage ref"
+                        }
+                      },
+                      "id": 1171,
+                      "isConstant": false,
+                      "isLValue": false,
+                      "isPure": false,
+                      "lValueRequested": false,
+                      "memberName": "push",
+                      "nodeType": "MemberAccess",
+                      "referencedDeclaration": null,
+                      "src": "29765:21:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_function_arraypush_nonpayable$_t_uint256_$returns$_t_uint256_$",
+                        "typeString": "function (uint256) returns (uint256)"
+                      }
+                    },
+                    "id": 1173,
+                    "isConstant": false,
+                    "isLValue": false,
+                    "isPure": false,
+                    "kind": "functionCall",
+                    "lValueRequested": false,
+                    "names": [],
+                    "nodeType": "FunctionCall",
+                    "src": "29765:30:1",
+                    "typeDescriptions": {
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+                              "referencedDeclaration": 1213,
+                              "src": "31387:10:1",
+                              "typeDescriptions": {
+                                "typeIdentifier": "t_uint256",
+                                "typeString": "uint256"
+                              }
+                            },
+                            "isConstant": false,
+                            "isLValue": true,
+                            "isPure": false,
+                            "lValueRequested": true,
+                            "nodeType": "IndexAccess",
+                            "src": "31368:30:1",
+                            "typeDescriptions": {
+                              "typeIdentifier": "t_uint256",
+                              "typeString": "uint256"
+                            }
+                          },
+                          "nodeType": "Assignment",
+                          "operator": "=",
+                          "rightHandSide": {
+                            "argumentTypes": null,
+                            "id": 1234,
+                            "name": "lastTokenId",
+                            "nodeType": "Identifier",
+                            "overloadedDeclarations": [],
+                            "referencedDeclaration": 1222,
+                            "src": "31401:11:1",
+                            "typeDescriptions": {
+                              "typeIdentifier": "t_uint256",
+                              "typeString": "uint256"
+                            }
+                          },
+                          "src": "31368:44:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_uint256",
+                            "typeString": "uint256"
+                          }
+                        },
+                        "id": 1236,
+                        "nodeType": "ExpressionStatement",
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+                      },
+                      {
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+                          "argumentTypes": null,
+                          "id": 1241,
+                          "isConstant": false,
+                          "isLValue": false,
+                          "isPure": false,
+                          "lValueRequested": false,
+                          "leftHandSide": {
+                            "argumentTypes": null,
+                            "baseExpression": {
+                              "argumentTypes": null,
+                              "id": 1237,
+                              "name": "_ownedTokensIndex",
+                              "nodeType": "Identifier",
+                              "overloadedDeclarations": [],
+                              "referencedDeclaration": 985,
+                              "src": "31484:17:1",
+                              "typeDescriptions": {
+                                "typeIdentifier": "t_mapping$_t_uint256_$_t_uint256_$",
+                                "typeString": "mapping(uint256 => uint256)"
+                              }
+                            },
+                            "id": 1239,
+                            "indexExpression": {
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+                              "id": 1238,
+                              "name": "lastTokenId",
+                              "nodeType": "Identifier",
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+                              "referencedDeclaration": 1222,
+                              "src": "31502:11:1",
+                              "typeDescriptions": {
+                                "typeIdentifier": "t_uint256",
+                                "typeString": "uint256"
+                              }
+                            },
+                            "isConstant": false,
+                            "isLValue": true,
+                            "isPure": false,
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+                            "nodeType": "IndexAccess",
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+                              "typeIdentifier": "t_uint256",
+                              "typeString": "uint256"
+                            }
+                          },
+                          "nodeType": "Assignment",
+                          "operator": "=",
+                          "rightHandSide": {
+                            "argumentTypes": null,
+                            "id": 1240,
+                            "name": "tokenIndex",
+                            "nodeType": "Identifier",
+                            "overloadedDeclarations": [],
+                            "referencedDeclaration": 1213,
+                            "src": "31517:10:1",
+                            "typeDescriptions": {
+                              "typeIdentifier": "t_uint256",
+                              "typeString": "uint256"
+                            }
+                          },
+                          "src": "31484:43:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_uint256",
+                            "typeString": "uint256"
+                          }
+                        },
+                        "id": 1242,
+                        "nodeType": "ExpressionStatement",
+                        "src": "31484:43:1"
+                      }
+                    ]
+                  }
+                },
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+                    "isConstant": false,
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+                    "isPure": false,
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+                      "expression": {
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+                        "baseExpression": {
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+                          "id": 1245,
+                          "name": "_ownedTokens",
+                          "nodeType": "Identifier",
+                          "overloadedDeclarations": [],
+                          "referencedDeclaration": 981,
+                          "src": "31658:12:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_mapping$_t_address_$_t_array$_t_uint256_$dyn_storage_$",
+                            "typeString": "mapping(address => uint256[] storage ref)"
+                          }
+                        },
+                        "id": 1247,
+                        "indexExpression": {
+                          "argumentTypes": null,
+                          "id": 1246,
+                          "name": "from",
+                          "nodeType": "Identifier",
+                          "overloadedDeclarations": [],
+                          "referencedDeclaration": 1197,
+                          "src": "31671:4:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_address",
+                            "typeString": "address"
+                          }
+                        },
+                        "isConstant": false,
+                        "isLValue": true,
+                        "isPure": false,
+                        "lValueRequested": false,
+                        "nodeType": "IndexAccess",
+                        "src": "31658:18:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_array$_t_uint256_$dyn_storage",
+                          "typeString": "uint256[] storage ref"
+                        }
+                      },
+                      "id": 1248,
+                      "isConstant": false,
+                      "isLValue": true,
+                      "isPure": false,
+                      "lValueRequested": true,
+                      "memberName": "length",
+                      "nodeType": "MemberAccess",
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+                      "src": "31658:25:1",
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+                        "typeString": "uint256"
+                      }
+                    },
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+                      "typeString": "uint256"
+                    }
+                  },
+                  "id": 1250,
+                  "nodeType": "ExpressionStatement",
+                  "src": "31658:27:1"
+                }
+              ]
+            },
+            "documentation": "@dev Private function to remove a token from this extension's ownership-tracking data structures. Note that\nwhile the token is not assigned a new owner, the _ownedTokensIndex mapping is _not_ updated: this allows for\ngas optimizations e.g. when performing a transfer operation (avoiding double writes).\nThis has O(1) time complexity, but alters the order of the _ownedTokens array.\n@param from address representing the previous owner of the given token ID\n@param tokenId uint256 ID of the token to be removed from the tokens list of the given address",
+            "id": 1252,
+            "implemented": true,
+            "kind": "function",
+            "modifiers": [],
+            "name": "_removeTokenFromOwnerEnumeration",
+            "nodeType": "FunctionDefinition",
+            "parameters": {
+              "id": 1200,
+              "nodeType": "ParameterList",
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+                  "id": 1197,
+                  "name": "from",
+                  "nodeType": "VariableDeclaration",
+                  "scope": 1252,
+                  "src": "30815:12:1",
+                  "stateVariable": false,
+                  "storageLocation": "default",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_address",
+                    "typeString": "address"
+                  },
+                  "typeName": {
+                    "id": 1196,
+                    "name": "address",
+                    "nodeType": "ElementaryTypeName",
+                    "src": "30815:7:1",
+                    "stateMutability": "nonpayable",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_address",
+                      "typeString": "address"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                },
+                {
+                  "constant": false,
+                  "id": 1199,
+                  "name": "tokenId",
+                  "nodeType": "VariableDeclaration",
+                  "scope": 1252,
+                  "src": "30829:15:1",
+                  "stateVariable": false,
+                  "storageLocation": "default",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_uint256",
+                    "typeString": "uint256"
+                  },
+                  "typeName": {
+                    "id": 1198,
+                    "name": "uint256",
+                    "nodeType": "ElementaryTypeName",
+                    "src": "30829:7:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_uint256",
+                      "typeString": "uint256"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                }
+              ],
+              "src": "30814:31:1"
+            },
+            "returnParameters": {
+              "id": 1201,
+              "nodeType": "ParameterList",
+              "parameters": [],
+              "src": "30854:0:1"
+            },
+            "scope": 1302,
+            "src": "30773:1128:1",
+            "stateMutability": "nonpayable",
+            "superFunction": null,
+            "visibility": "private"
+          },
+          {
+            "body": {
+              "id": 1300,
+              "nodeType": "Block",
+              "src": "32260:993:1",
+              "statements": [
+                {
+                  "assignments": [
+                    1258
+                  ],
+                  "declarations": [
+                    {
+                      "constant": false,
+                      "id": 1258,
+                      "name": "lastTokenIndex",
+                      "nodeType": "VariableDeclaration",
+                      "scope": 1300,
+                      "src": "32438:22:1",
+                      "stateVariable": false,
+                      "storageLocation": "default",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_uint256",
+                        "typeString": "uint256"
+                      },
+                      "typeName": {
+                        "id": 1257,
+                        "name": "uint256",
+                        "nodeType": "ElementaryTypeName",
+                        "src": "32438:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      },
+                      "value": null,
+                      "visibility": "internal"
+                    }
+                  ],
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+                  "initialValue": {
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+                    "arguments": [
+                      {
+                        "argumentTypes": null,
+                        "hexValue": "31",
+                        "id": 1262,
+                        "isConstant": false,
+                        "isLValue": false,
+                        "isPure": true,
+                        "kind": "number",
+                        "lValueRequested": false,
+                        "nodeType": "Literal",
+                        "src": "32485:1:1",
+                        "subdenomination": null,
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_rational_1_by_1",
+                          "typeString": "int_const 1"
+                        },
+                        "value": "1"
+                      }
+                    ],
+                    "expression": {
+                      "argumentTypes": [
+                        {
+                          "typeIdentifier": "t_rational_1_by_1",
+                          "typeString": "int_const 1"
+                        }
+                      ],
+                      "expression": {
+                        "argumentTypes": null,
+                        "expression": {
+                          "argumentTypes": null,
+                          "id": 1259,
+                          "name": "_allTokens",
+                          "nodeType": "Identifier",
+                          "overloadedDeclarations": [],
+                          "referencedDeclaration": 988,
+                          "src": "32463:10:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_array$_t_uint256_$dyn_storage",
+                            "typeString": "uint256[] storage ref"
+                          }
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+                        "isLValue": true,
+                        "isPure": false,
+                        "lValueRequested": false,
+                        "memberName": "length",
+                        "nodeType": "MemberAccess",
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+                        "src": "32463:17:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
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+                      "isLValue": false,
+                      "isPure": false,
+                      "lValueRequested": false,
+                      "memberName": "sub",
+                      "nodeType": "MemberAccess",
+                      "referencedDeclaration": 190,
+                      "src": "32463:21:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_function_internal_pure$_t_uint256_$_t_uint256_$returns$_t_uint256_$bound_to$_t_uint256_$",
+                        "typeString": "function (uint256,uint256) pure returns (uint256)"
+                      }
+                    },
+                    "id": 1263,
+                    "isConstant": false,
+                    "isLValue": false,
+                    "isPure": false,
+                    "kind": "functionCall",
+                    "lValueRequested": false,
+                    "names": [],
+                    "nodeType": "FunctionCall",
+                    "src": "32463:24:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_uint256",
+                      "typeString": "uint256"
+                    }
+                  },
+                  "nodeType": "VariableDeclarationStatement",
+                  "src": "32438:49:1"
+                },
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+                      "id": 1266,
+                      "name": "tokenIndex",
+                      "nodeType": "VariableDeclaration",
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+                      "src": "32497:18:1",
+                      "stateVariable": false,
+                      "storageLocation": "default",
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+                        "typeIdentifier": "t_uint256",
+                        "typeString": "uint256"
+                      },
+                      "typeName": {
+                        "id": 1265,
+                        "name": "uint256",
+                        "nodeType": "ElementaryTypeName",
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+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      },
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+                      "visibility": "internal"
+                    }
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+                  "initialValue": {
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+                      "id": 1267,
+                      "name": "_allTokensIndex",
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+                      "src": "32518:15:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_mapping$_t_uint256_$_t_uint256_$",
+                        "typeString": "mapping(uint256 => uint256)"
+                      }
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+                    "indexExpression": {
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+                      "id": 1268,
+                      "name": "tokenId",
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+                      "src": "32534:7:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_uint256",
+                        "typeString": "uint256"
+                      }
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+                    "isPure": false,
+                    "lValueRequested": false,
+                    "nodeType": "IndexAccess",
+                    "src": "32518:24:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_uint256",
+                      "typeString": "uint256"
+                    }
+                  },
+                  "nodeType": "VariableDeclarationStatement",
+                  "src": "32497:45:1"
+                },
+                {
+                  "assignments": [
+                    1272
+                  ],
+                  "declarations": [
+                    {
+                      "constant": false,
+                      "id": 1272,
+                      "name": "lastTokenId",
+                      "nodeType": "VariableDeclaration",
+                      "scope": 1300,
+                      "src": "32864:19:1",
+                      "stateVariable": false,
+                      "storageLocation": "default",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_uint256",
+                        "typeString": "uint256"
+                      },
+                      "typeName": {
+                        "id": 1271,
+                        "name": "uint256",
+                        "nodeType": "ElementaryTypeName",
+                        "src": "32864:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      },
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+                      "visibility": "internal"
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+                      "src": "32886:10:1",
+                      "typeDescriptions": {
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+                        "typeString": "uint256[] storage ref"
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+                      "id": 1274,
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+                      "src": "32897:14:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_uint256",
+                        "typeString": "uint256"
+                      }
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+                    "nodeType": "IndexAccess",
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+                      "typeIdentifier": "t_uint256",
+                      "typeString": "uint256"
+                    }
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+                        "src": "32923:10:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_array$_t_uint256_$dyn_storage",
+                          "typeString": "uint256[] storage ref"
+                        }
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+                        "typeString": "uint256"
+                      }
+                    },
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+                        "typeIdentifier": "t_uint256",
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+                        "src": "33027:15:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_mapping$_t_uint256_$_t_uint256_$",
+                          "typeString": "mapping(uint256 => uint256)"
+                        }
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+                        "src": "33189:10:1",
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+                            "typeString": "address"
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+                        "id": 911,
+                        "name": "_data",
+                        "nodeType": "Identifier",
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+                        "src": "23657:5:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_bytes_memory_ptr",
+                          "typeString": "bytes memory"
+                        }
+                      }
+                    ],
+                    "expression": {
+                      "argumentTypes": [
+                        {
+                          "typeIdentifier": "t_address_payable",
+                          "typeString": "address payable"
+                        },
+                        {
+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        },
+                        {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        },
+                        {
+                          "typeIdentifier": "t_bytes_memory_ptr",
+                          "typeString": "bytes memory"
+                        }
+                      ],
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+                        "arguments": [
+                          {
+                            "argumentTypes": null,
+                            "id": 904,
+                            "name": "to",
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+                            "src": "23609:2:1",
+                            "typeDescriptions": {
+                              "typeIdentifier": "t_address",
+                              "typeString": "address"
+                            }
+                          }
+                        ],
+                        "expression": {
+                          "argumentTypes": [
+                            {
+                              "typeIdentifier": "t_address",
+                              "typeString": "address"
+                            }
+                          ],
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+                          "name": "IERC721Receiver",
+                          "nodeType": "Identifier",
+                          "overloadedDeclarations": [],
+                          "referencedDeclaration": 139,
+                          "src": "23593:15:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_type$_t_contract$_IERC721Receiver_$139_$",
+                            "typeString": "type(contract IERC721Receiver)"
+                          }
+                        },
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+                        "isPure": false,
+                        "kind": "typeConversion",
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+                        "nodeType": "FunctionCall",
+                        "src": "23593:19:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_contract$_IERC721Receiver_$139",
+                          "typeString": "contract IERC721Receiver"
+                        }
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+                      "lValueRequested": false,
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+                        "typeString": "function (address,address,uint256,bytes memory) external returns (bytes4)"
+                      }
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+                    "isConstant": false,
+                    "isLValue": false,
+                    "isPure": false,
+                    "kind": "functionCall",
+                    "lValueRequested": false,
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+                    "nodeType": "FunctionCall",
+                    "src": "23593:70:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_bytes4",
+                      "typeString": "bytes4"
+                    }
+                  },
+                  "nodeType": "VariableDeclarationStatement",
+                  "src": "23577:86:1"
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+                    "components": [
+                      {
+                        "argumentTypes": null,
+                        "commonType": {
+                          "typeIdentifier": "t_bytes4",
+                          "typeString": "bytes4"
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+                        "isPure": false,
+                        "lValueRequested": false,
+                        "leftExpression": {
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+                          "id": 914,
+                          "name": "retval",
+                          "nodeType": "Identifier",
+                          "overloadedDeclarations": [],
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+                          "src": "23681:6:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_bytes4",
+                            "typeString": "bytes4"
+                          }
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+                        "operator": "==",
+                        "rightExpression": {
+                          "argumentTypes": null,
+                          "id": 915,
+                          "name": "_ERC721_RECEIVED",
+                          "nodeType": "Identifier",
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+                          "referencedDeclaration": 403,
+                          "src": "23691:16:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_bytes4",
+                            "typeString": "bytes4"
+                          }
+                        },
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+                          "typeIdentifier": "t_bool",
+                          "typeString": "bool"
+                        }
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+                }
+              ]
+            },
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+                  "visibility": "internal"
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+                      "typeString": "uint256"
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+                  "visibility": "internal"
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+                      "typeString": "bytes"
+                    }
+                  },
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+                  "visibility": "internal"
+                }
+              ],
+              "src": "23399:63:1"
+            },
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+              "nodeType": "ParameterList",
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+                  "name": "",
+                  "nodeType": "VariableDeclaration",
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+                  "src": "23489:4:1",
+                  "stateVariable": false,
+                  "storageLocation": "default",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_bool",
+                    "typeString": "bool"
+                  },
+                  "typeName": {
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+                    "name": "bool",
+                    "nodeType": "ElementaryTypeName",
+                    "src": "23489:4:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_bool",
+                      "typeString": "bool"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                }
+              ],
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+            "src": "23368:347:1",
+            "stateMutability": "nonpayable",
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+            "visibility": "internal"
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+                    "commonType": {
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+                        "id": 925,
+                        "name": "_tokenApprovals",
+                        "nodeType": "Identifier",
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+                        "referencedDeclaration": 411,
+                        "src": "23940:15:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_mapping$_t_uint256_$_t_address_$",
+                          "typeString": "mapping(uint256 => address)"
+                        }
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+                        "id": 926,
+                        "name": "tokenId",
+                        "nodeType": "Identifier",
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+                        "referencedDeclaration": 922,
+                        "src": "23956:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
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+                        "typeString": "address"
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+                      "arguments": [
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+                          "argumentTypes": null,
+                          "hexValue": "30",
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+                          "isLValue": false,
+                          "isPure": true,
+                          "kind": "number",
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+                          "nodeType": "Literal",
+                          "src": "23976:1:1",
+                          "subdenomination": null,
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_rational_0_by_1",
+                            "typeString": "int_const 0"
+                          },
+                          "value": "0"
+                        }
+                      ],
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+                        "argumentTypes": [
+                          {
+                            "typeIdentifier": "t_rational_0_by_1",
+                            "typeString": "int_const 0"
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+                        "isConstant": false,
+                        "isLValue": false,
+                        "isPure": true,
+                        "lValueRequested": false,
+                        "nodeType": "ElementaryTypeNameExpression",
+                        "src": "23968:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_type$_t_address_$",
+                          "typeString": "type(address)"
+                        },
+                        "typeName": "address"
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+                      "names": [],
+                      "nodeType": "FunctionCall",
+                      "src": "23968:10:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_address_payable",
+                        "typeString": "address payable"
+                      }
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+                    "typeDescriptions": {
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+                      "typeString": "bool"
+                    }
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+                  "nodeType": "IfStatement",
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+                          "isLValue": false,
+                          "isPure": false,
+                          "lValueRequested": false,
+                          "leftHandSide": {
+                            "argumentTypes": null,
+                            "baseExpression": {
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+                              "id": 932,
+                              "name": "_tokenApprovals",
+                              "nodeType": "Identifier",
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+                              "referencedDeclaration": 411,
+                              "src": "23994:15:1",
+                              "typeDescriptions": {
+                                "typeIdentifier": "t_mapping$_t_uint256_$_t_address_$",
+                                "typeString": "mapping(uint256 => address)"
+                              }
+                            },
+                            "id": 934,
+                            "indexExpression": {
+                              "argumentTypes": null,
+                              "id": 933,
+                              "name": "tokenId",
+                              "nodeType": "Identifier",
+                              "overloadedDeclarations": [],
+                              "referencedDeclaration": 922,
+                              "src": "24010:7:1",
+                              "typeDescriptions": {
+                                "typeIdentifier": "t_uint256",
+                                "typeString": "uint256"
+                              }
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+                            "isLValue": true,
+                            "isPure": false,
+                            "lValueRequested": true,
+                            "nodeType": "IndexAccess",
+                            "src": "23994:24:1",
+                            "typeDescriptions": {
+                              "typeIdentifier": "t_address",
+                              "typeString": "address"
+                            }
+                          },
+                          "nodeType": "Assignment",
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+                          "rightHandSide": {
+                            "argumentTypes": null,
+                            "arguments": [
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+                                "argumentTypes": null,
+                                "hexValue": "30",
+                                "id": 936,
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+                                "isLValue": false,
+                                "isPure": true,
+                                "kind": "number",
+                                "lValueRequested": false,
+                                "nodeType": "Literal",
+                                "src": "24029:1:1",
+                                "subdenomination": null,
+                                "typeDescriptions": {
+                                  "typeIdentifier": "t_rational_0_by_1",
+                                  "typeString": "int_const 0"
+                                },
+                                "value": "0"
+                              }
+                            ],
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+                              "argumentTypes": [
+                                {
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+                                  "typeString": "int_const 0"
+                                }
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+                              "isLValue": false,
+                              "isPure": true,
+                              "lValueRequested": false,
+                              "nodeType": "ElementaryTypeNameExpression",
+                              "src": "24021:7:1",
+                              "typeDescriptions": {
+                                "typeIdentifier": "t_type$_t_address_$",
+                                "typeString": "type(address)"
+                              },
+                              "typeName": "address"
+                            },
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+                            "isLValue": false,
+                            "isPure": true,
+                            "kind": "typeConversion",
+                            "lValueRequested": false,
+                            "names": [],
+                            "nodeType": "FunctionCall",
+                            "src": "24021:10:1",
+                            "typeDescriptions": {
+                              "typeIdentifier": "t_address_payable",
+                              "typeString": "address payable"
+                            }
+                          },
+                          "src": "23994:37:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_address",
+                            "typeString": "address"
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+                        "nodeType": "ExpressionStatement",
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+                      }
+                    ]
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+                }
+              ]
+            },
+            "documentation": "@dev Private function to clear current approval of a given token ID.\n@param tokenId uint256 ID of the token to be transferred",
+            "id": 943,
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+            "kind": "function",
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+                  "storageLocation": "default",
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+                    "name": "uint256",
+                    "nodeType": "ElementaryTypeName",
+                    "src": "23901:7:1",
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+                  "visibility": "internal"
+                }
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+            },
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+              "src": "23926:0:1"
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+            "visibility": "private"
+          }
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+      {
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+        "literals": [
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+        "nodeType": "PragmaDirective",
+        "src": "24121:23:1"
+      },
+      {
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+            "baseName": {
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+              "id": 946,
+              "name": "IERC721",
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+              "src": "24314:7:1",
+              "typeDescriptions": {
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+                "typeString": "contract IERC721"
+              }
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+            "nodeType": "InheritanceSpecifier",
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+        ],
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+        ],
+        "contractKind": "contract",
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+        "id": 969,
+        "linearizedBaseContracts": [
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+        "name": "IERC721Enumerable",
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+            "stateMutability": "view",
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+                        "typeString": "uint256[] storage ref"
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+                      "nodeType": "Identifier",
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+                      "src": "26496:5:1",
+                      "typeDescriptions": {
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+                  "storageLocation": "default",
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+                    "typeString": "address"
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+                    "name": "address",
+                    "nodeType": "ElementaryTypeName",
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+                    "stateMutability": "nonpayable",
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+                      "typeString": "address"
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+                      "nodeType": "Identifier",
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+                      "src": "26732:10:1",
+                      "typeDescriptions": {
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+                    "memberName": "length",
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+                    "src": "26732:17:1",
+                    "typeDescriptions": {
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+                  "nodeType": "Return",
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+                }
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+            "implemented": true,
+            "kind": "function",
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+                      "typeString": "uint256"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                }
+              ],
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+            },
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+            "src": "26662:94:1",
+            "stateMutability": "view",
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+                        "commonType": {
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+                          "id": 1045,
+                          "name": "index",
+                          "nodeType": "Identifier",
+                          "overloadedDeclarations": [],
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+                          "src": "27179:5:1",
+                          "typeDescriptions": {
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+                            "typeString": "uint256"
+                          }
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+                        "operator": "<",
+                        "rightExpression": {
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+                          "arguments": [],
+                          "expression": {
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+                            "id": 1046,
+                            "name": "totalSupply",
+                            "nodeType": "Identifier",
+                            "overloadedDeclarations": [
+                              1037
+                            ],
+                            "referencedDeclaration": 1037,
+                            "src": "27187:11:1",
+                            "typeDescriptions": {
+                              "typeIdentifier": "t_function_internal_view$__$returns$_t_uint256_$",
+                              "typeString": "function () view returns (uint256)"
+                            }
+                          },
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+                          "isConstant": false,
+                          "isLValue": false,
+                          "isPure": false,
+                          "kind": "functionCall",
+                          "lValueRequested": false,
+                          "names": [],
+                          "nodeType": "FunctionCall",
+                          "src": "27187:13:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_uint256",
+                            "typeString": "uint256"
+                          }
+                        },
+                        "src": "27179:21:1",
+                        "typeDescriptions": {
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+                          "typeString": "bool"
+                        }
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+                        "isPure": true,
+                        "kind": "string",
+                        "lValueRequested": false,
+                        "nodeType": "Literal",
+                        "src": "27202:46:1",
+                        "subdenomination": null,
+                        "typeDescriptions": {
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+                          "typeString": "literal_string \"ERC721Enumerable: global index out of bounds\""
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+                        "value": "ERC721Enumerable: global index out of bounds"
+                      }
+                    ],
+                    "expression": {
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+                          "typeString": "bool"
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+                      "src": "27171:7:1",
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+                        "typeString": "function (bool,string memory) pure"
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+                    "kind": "functionCall",
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+                    "baseExpression": {
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+                      "id": 1052,
+                      "name": "_allTokens",
+                      "nodeType": "Identifier",
+                      "overloadedDeclarations": [],
+                      "referencedDeclaration": 988,
+                      "src": "27266:10:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_array$_t_uint256_$dyn_storage",
+                        "typeString": "uint256[] storage ref"
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+                    "id": 1054,
+                    "indexExpression": {
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+                      "id": 1053,
+                      "name": "index",
+                      "nodeType": "Identifier",
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+                      "referencedDeclaration": 1039,
+                      "src": "27277:5:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_uint256",
+                        "typeString": "uint256"
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+                      "typeString": "uint256"
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+                  "nodeType": "Return",
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+                }
+              ]
+            },
+            "documentation": "@dev Gets the token ID at a given index of all the tokens in this contract\nReverts if the index is greater or equal to the total number of tokens.\n@param index uint256 representing the index to be accessed of the tokens list\n@return uint256 token ID at the given index of the tokens list",
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+            "implemented": true,
+            "kind": "function",
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+                  "stateVariable": false,
+                  "storageLocation": "default",
+                  "typeDescriptions": {
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+                    "typeString": "uint256"
+                  },
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+                    "name": "uint256",
+                    "nodeType": "ElementaryTypeName",
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+                    "typeDescriptions": {
+                      "typeIdentifier": "t_uint256",
+                      "typeString": "uint256"
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+                  "value": null,
+                  "visibility": "internal"
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+                  "nodeType": "VariableDeclaration",
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+                  "storageLocation": "default",
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+                        "referencedDeclaration": 1059,
+                        "src": "27770:4:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        }
+                      },
+                      {
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+                        "id": 1070,
+                        "name": "to",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 1061,
+                        "src": "27776:2:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        }
+                      },
+                      {
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+                        "id": 1071,
+                        "name": "tokenId",
+                        "nodeType": "Identifier",
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+                        "referencedDeclaration": 1063,
+                        "src": "27780:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      }
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+                      "argumentTypes": [
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+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
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+                        {
+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        },
+                        {
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+                        "name": "super",
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+                        "src": "27750:5:1",
+                        "typeDescriptions": {
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+                          "typeString": "contract super ERC721Enumerable"
+                        }
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+                        "src": "27832:4:1",
+                        "typeDescriptions": {
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+                          "typeString": "address"
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+                      {
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+                        "id": 1076,
+                        "name": "tokenId",
+                        "nodeType": "Identifier",
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+                          "typeString": "address"
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+                          "typeString": "uint256"
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+                        "name": "to",
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+                        "src": "27885:2:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        }
+                      },
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+                        "id": 1081,
+                        "name": "tokenId",
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+                          "typeString": "address"
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+                          "typeString": "uint256"
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+                      "src": "27857:27:1",
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+              ]
+            },
+            "documentation": "@dev Internal function to transfer ownership of a given token ID to another address.\nAs opposed to transferFrom, this imposes no restrictions on msg.sender.\n@param from current owner of the token\n@param to address to receive the ownership of the given token ID\n@param tokenId uint256 ID of the token to be transferred",
+            "id": 1085,
+            "implemented": true,
+            "kind": "function",
+            "modifiers": [],
+            "name": "_transferFrom",
+            "nodeType": "FunctionDefinition",
+            "parameters": {
+              "id": 1064,
+              "nodeType": "ParameterList",
+              "parameters": [
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+                  "id": 1059,
+                  "name": "from",
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+                  "scope": 1085,
+                  "src": "27688:12:1",
+                  "stateVariable": false,
+                  "storageLocation": "default",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_address",
+                    "typeString": "address"
+                  },
+                  "typeName": {
+                    "id": 1058,
+                    "name": "address",
+                    "nodeType": "ElementaryTypeName",
+                    "src": "27688:7:1",
+                    "stateMutability": "nonpayable",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_address",
+                      "typeString": "address"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                },
+                {
+                  "constant": false,
+                  "id": 1061,
+                  "name": "to",
+                  "nodeType": "VariableDeclaration",
+                  "scope": 1085,
+                  "src": "27702:10:1",
+                  "stateVariable": false,
+                  "storageLocation": "default",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_address",
+                    "typeString": "address"
+                  },
+                  "typeName": {
+                    "id": 1060,
+                    "name": "address",
+                    "nodeType": "ElementaryTypeName",
+                    "src": "27702:7:1",
+                    "stateMutability": "nonpayable",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_address",
+                      "typeString": "address"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                },
+                {
+                  "constant": false,
+                  "id": 1063,
+                  "name": "tokenId",
+                  "nodeType": "VariableDeclaration",
+                  "scope": 1085,
+                  "src": "27714:15:1",
+                  "stateVariable": false,
+                  "storageLocation": "default",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_uint256",
+                    "typeString": "uint256"
+                  },
+                  "typeName": {
+                    "id": 1062,
+                    "name": "uint256",
+                    "nodeType": "ElementaryTypeName",
+                    "src": "27714:7:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_uint256",
+                      "typeString": "uint256"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                }
+              ],
+              "src": "27687:43:1"
+            },
+            "returnParameters": {
+              "id": 1065,
+              "nodeType": "ParameterList",
+              "parameters": [],
+              "src": "27740:0:1"
+            },
+            "scope": 1302,
+            "src": "27665:239:1",
+            "stateMutability": "nonpayable",
+            "superFunction": 880,
+            "visibility": "internal"
+          },
+          {
+            "body": {
+              "id": 1108,
+              "nodeType": "Block",
+              "src": "28214:143:1",
+              "statements": [
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+                    "argumentTypes": null,
+                    "arguments": [
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+                        "argumentTypes": null,
+                        "id": 1095,
+                        "name": "to",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 1087,
+                        "src": "28236:2:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        }
+                      },
+                      {
+                        "argumentTypes": null,
+                        "id": 1096,
+                        "name": "tokenId",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 1089,
+                        "src": "28240:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      }
+                    ],
+                    "expression": {
+                      "argumentTypes": [
+                        {
+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        },
+                        {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      ],
+                      "expression": {
+                        "argumentTypes": null,
+                        "id": 1092,
+                        "name": "super",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 1572,
+                        "src": "28224:5:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_super$_ERC721Enumerable_$1302",
+                          "typeString": "contract super ERC721Enumerable"
+                        }
+                      },
+                      "id": 1094,
+                      "isConstant": false,
+                      "isLValue": false,
+                      "isPure": false,
+                      "lValueRequested": false,
+                      "memberName": "_mint",
+                      "nodeType": "MemberAccess",
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+                      "src": "28224:11:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_function_internal_nonpayable$_t_address_$_t_uint256_$returns$__$",
+                        "typeString": "function (address,uint256)"
+                      }
+                    },
+                    "id": 1097,
+                    "isConstant": false,
+                    "isLValue": false,
+                    "isPure": false,
+                    "kind": "functionCall",
+                    "lValueRequested": false,
+                    "names": [],
+                    "nodeType": "FunctionCall",
+                    "src": "28224:24:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_tuple$__$",
+                      "typeString": "tuple()"
+                    }
+                  },
+                  "id": 1098,
+                  "nodeType": "ExpressionStatement",
+                  "src": "28224:24:1"
+                },
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+                  "expression": {
+                    "argumentTypes": null,
+                    "arguments": [
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+                        "argumentTypes": null,
+                        "id": 1100,
+                        "name": "to",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 1087,
+                        "src": "28287:2:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        }
+                      },
+                      {
+                        "argumentTypes": null,
+                        "id": 1101,
+                        "name": "tokenId",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 1089,
+                        "src": "28291:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      }
+                    ],
+                    "expression": {
+                      "argumentTypes": [
+                        {
+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        },
+                        {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      ],
+                      "id": 1099,
+                      "name": "_addTokenToOwnerEnumeration",
+                      "nodeType": "Identifier",
+                      "overloadedDeclarations": [],
+                      "referencedDeclaration": 1176,
+                      "src": "28259:27:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_function_internal_nonpayable$_t_address_$_t_uint256_$returns$__$",
+                        "typeString": "function (address,uint256)"
+                      }
+                    },
+                    "id": 1102,
+                    "isConstant": false,
+                    "isLValue": false,
+                    "isPure": false,
+                    "kind": "functionCall",
+                    "lValueRequested": false,
+                    "names": [],
+                    "nodeType": "FunctionCall",
+                    "src": "28259:40:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_tuple$__$",
+                      "typeString": "tuple()"
+                    }
+                  },
+                  "id": 1103,
+                  "nodeType": "ExpressionStatement",
+                  "src": "28259:40:1"
+                },
+                {
+                  "expression": {
+                    "argumentTypes": null,
+                    "arguments": [
+                      {
+                        "argumentTypes": null,
+                        "id": 1105,
+                        "name": "tokenId",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 1089,
+                        "src": "28342:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      }
+                    ],
+                    "expression": {
+                      "argumentTypes": [
+                        {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      ],
+                      "id": 1104,
+                      "name": "_addTokenToAllTokensEnumeration",
+                      "nodeType": "Identifier",
+                      "overloadedDeclarations": [],
+                      "referencedDeclaration": 1195,
+                      "src": "28310:31:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_function_internal_nonpayable$_t_uint256_$returns$__$",
+                        "typeString": "function (uint256)"
+                      }
+                    },
+                    "id": 1106,
+                    "isConstant": false,
+                    "isLValue": false,
+                    "isPure": false,
+                    "kind": "functionCall",
+                    "lValueRequested": false,
+                    "names": [],
+                    "nodeType": "FunctionCall",
+                    "src": "28310:40:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_tuple$__$",
+                      "typeString": "tuple()"
+                    }
+                  },
+                  "id": 1107,
+                  "nodeType": "ExpressionStatement",
+                  "src": "28310:40:1"
+                }
+              ]
+            },
+            "documentation": "@dev Internal function to mint a new token.\nReverts if the given token ID already exists.\n@param to address the beneficiary that will own the minted token\n@param tokenId uint256 ID of the token to be minted",
+            "id": 1109,
+            "implemented": true,
+            "kind": "function",
+            "modifiers": [],
+            "name": "_mint",
+            "nodeType": "FunctionDefinition",
+            "parameters": {
+              "id": 1090,
+              "nodeType": "ParameterList",
+              "parameters": [
+                {
+                  "constant": false,
+                  "id": 1087,
+                  "name": "to",
+                  "nodeType": "VariableDeclaration",
+                  "scope": 1109,
+                  "src": "28176:10:1",
+                  "stateVariable": false,
+                  "storageLocation": "default",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_address",
+                    "typeString": "address"
+                  },
+                  "typeName": {
+                    "id": 1086,
+                    "name": "address",
+                    "nodeType": "ElementaryTypeName",
+                    "src": "28176:7:1",
+                    "stateMutability": "nonpayable",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_address",
+                      "typeString": "address"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                },
+                {
+                  "constant": false,
+                  "id": 1089,
+                  "name": "tokenId",
+                  "nodeType": "VariableDeclaration",
+                  "scope": 1109,
+                  "src": "28188:15:1",
+                  "stateVariable": false,
+                  "storageLocation": "default",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_uint256",
+                    "typeString": "uint256"
+                  },
+                  "typeName": {
+                    "id": 1088,
+                    "name": "uint256",
+                    "nodeType": "ElementaryTypeName",
+                    "src": "28188:7:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_uint256",
+                      "typeString": "uint256"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                }
+              ],
+              "src": "28175:29:1"
+            },
+            "returnParameters": {
+              "id": 1091,
+              "nodeType": "ParameterList",
+              "parameters": [],
+              "src": "28214:0:1"
+            },
+            "scope": 1302,
+            "src": "28161:196:1",
+            "stateMutability": "nonpayable",
+            "superFunction": 768,
+            "visibility": "internal"
+          },
+          {
+            "body": {
+              "id": 1138,
+              "nodeType": "Block",
+              "src": "28688:308:1",
+              "statements": [
+                {
+                  "expression": {
+                    "argumentTypes": null,
+                    "arguments": [
+                      {
+                        "argumentTypes": null,
+                        "id": 1119,
+                        "name": "owner",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 1111,
+                        "src": "28710:5:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        }
+                      },
+                      {
+                        "argumentTypes": null,
+                        "id": 1120,
+                        "name": "tokenId",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 1113,
+                        "src": "28717:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      }
+                    ],
+                    "expression": {
+                      "argumentTypes": [
+                        {
+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        },
+                        {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      ],
+                      "expression": {
+                        "argumentTypes": null,
+                        "id": 1116,
+                        "name": "super",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 1572,
+                        "src": "28698:5:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_super$_ERC721Enumerable_$1302",
+                          "typeString": "contract super ERC721Enumerable"
+                        }
+                      },
+                      "id": 1118,
+                      "isConstant": false,
+                      "isLValue": false,
+                      "isPure": false,
+                      "lValueRequested": false,
+                      "memberName": "_burn",
+                      "nodeType": "MemberAccess",
+                      "referencedDeclaration": 811,
+                      "src": "28698:11:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_function_internal_nonpayable$_t_address_$_t_uint256_$returns$__$",
+                        "typeString": "function (address,uint256)"
+                      }
+                    },
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+                    "isConstant": false,
+                    "isLValue": false,
+                    "isPure": false,
+                    "kind": "functionCall",
+                    "lValueRequested": false,
+                    "names": [],
+                    "nodeType": "FunctionCall",
+                    "src": "28698:27:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_tuple$__$",
+                      "typeString": "tuple()"
+                    }
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+                  "id": 1122,
+                  "nodeType": "ExpressionStatement",
+                  "src": "28698:27:1"
+                },
+                {
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+                    "argumentTypes": null,
+                    "arguments": [
+                      {
+                        "argumentTypes": null,
+                        "id": 1124,
+                        "name": "owner",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 1111,
+                        "src": "28769:5:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        }
+                      },
+                      {
+                        "argumentTypes": null,
+                        "id": 1125,
+                        "name": "tokenId",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 1113,
+                        "src": "28776:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      }
+                    ],
+                    "expression": {
+                      "argumentTypes": [
+                        {
+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        },
+                        {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      ],
+                      "id": 1123,
+                      "name": "_removeTokenFromOwnerEnumeration",
+                      "nodeType": "Identifier",
+                      "overloadedDeclarations": [],
+                      "referencedDeclaration": 1252,
+                      "src": "28736:32:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_function_internal_nonpayable$_t_address_$_t_uint256_$returns$__$",
+                        "typeString": "function (address,uint256)"
+                      }
+                    },
+                    "id": 1126,
+                    "isConstant": false,
+                    "isLValue": false,
+                    "isPure": false,
+                    "kind": "functionCall",
+                    "lValueRequested": false,
+                    "names": [],
+                    "nodeType": "FunctionCall",
+                    "src": "28736:48:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_tuple$__$",
+                      "typeString": "tuple()"
+                    }
+                  },
+                  "id": 1127,
+                  "nodeType": "ExpressionStatement",
+                  "src": "28736:48:1"
+                },
+                {
+                  "expression": {
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+                    "id": 1132,
+                    "isConstant": false,
+                    "isLValue": false,
+                    "isPure": false,
+                    "lValueRequested": false,
+                    "leftHandSide": {
+                      "argumentTypes": null,
+                      "baseExpression": {
+                        "argumentTypes": null,
+                        "id": 1128,
+                        "name": "_ownedTokensIndex",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 985,
+                        "src": "28903:17:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_mapping$_t_uint256_$_t_uint256_$",
+                          "typeString": "mapping(uint256 => uint256)"
+                        }
+                      },
+                      "id": 1130,
+                      "indexExpression": {
+                        "argumentTypes": null,
+                        "id": 1129,
+                        "name": "tokenId",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 1113,
+                        "src": "28921:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      },
+                      "isConstant": false,
+                      "isLValue": true,
+                      "isPure": false,
+                      "lValueRequested": true,
+                      "nodeType": "IndexAccess",
+                      "src": "28903:26:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_uint256",
+                        "typeString": "uint256"
+                      }
+                    },
+                    "nodeType": "Assignment",
+                    "operator": "=",
+                    "rightHandSide": {
+                      "argumentTypes": null,
+                      "hexValue": "30",
+                      "id": 1131,
+                      "isConstant": false,
+                      "isLValue": false,
+                      "isPure": true,
+                      "kind": "number",
+                      "lValueRequested": false,
+                      "nodeType": "Literal",
+                      "src": "28932:1:1",
+                      "subdenomination": null,
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_rational_0_by_1",
+                        "typeString": "int_const 0"
+                      },
+                      "value": "0"
+                    },
+                    "src": "28903:30:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_uint256",
+                      "typeString": "uint256"
+                    }
+                  },
+                  "id": 1133,
+                  "nodeType": "ExpressionStatement",
+                  "src": "28903:30:1"
+                },
+                {
+                  "expression": {
+                    "argumentTypes": null,
+                    "arguments": [
+                      {
+                        "argumentTypes": null,
+                        "id": 1135,
+                        "name": "tokenId",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 1113,
+                        "src": "28981:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      }
+                    ],
+                    "expression": {
+                      "argumentTypes": [
+                        {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      ],
+                      "id": 1134,
+                      "name": "_removeTokenFromAllTokensEnumeration",
+                      "nodeType": "Identifier",
+                      "overloadedDeclarations": [],
+                      "referencedDeclaration": 1301,
+                      "src": "28944:36:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_function_internal_nonpayable$_t_uint256_$returns$__$",
+                        "typeString": "function (uint256)"
+                      }
+                    },
+                    "id": 1136,
+                    "isConstant": false,
+                    "isLValue": false,
+                    "isPure": false,
+                    "kind": "functionCall",
+                    "lValueRequested": false,
+                    "names": [],
+                    "nodeType": "FunctionCall",
+                    "src": "28944:45:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_tuple$__$",
+                      "typeString": "tuple()"
+                    }
+                  },
+                  "id": 1137,
+                  "nodeType": "ExpressionStatement",
+                  "src": "28944:45:1"
+                }
+              ]
+            },
+            "documentation": "@dev Internal function to burn a specific token.\nReverts if the token does not exist.\nDeprecated, use _burn(uint256) instead.\n@param owner owner of the token to burn\n@param tokenId uint256 ID of the token being burned",
+            "id": 1139,
+            "implemented": true,
+            "kind": "function",
+            "modifiers": [],
+            "name": "_burn",
+            "nodeType": "FunctionDefinition",
+            "parameters": {
+              "id": 1114,
+              "nodeType": "ParameterList",
+              "parameters": [
+                {
+                  "constant": false,
+                  "id": 1111,
+                  "name": "owner",
+                  "nodeType": "VariableDeclaration",
+                  "scope": 1139,
+                  "src": "28647:13:1",
+                  "stateVariable": false,
+                  "storageLocation": "default",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_address",
+                    "typeString": "address"
+                  },
+                  "typeName": {
+                    "id": 1110,
+                    "name": "address",
+                    "nodeType": "ElementaryTypeName",
+                    "src": "28647:7:1",
+                    "stateMutability": "nonpayable",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_address",
+                      "typeString": "address"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                },
+                {
+                  "constant": false,
+                  "id": 1113,
+                  "name": "tokenId",
+                  "nodeType": "VariableDeclaration",
+                  "scope": 1139,
+                  "src": "28662:15:1",
+                  "stateVariable": false,
+                  "storageLocation": "default",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_uint256",
+                    "typeString": "uint256"
+                  },
+                  "typeName": {
+                    "id": 1112,
+                    "name": "uint256",
+                    "nodeType": "ElementaryTypeName",
+                    "src": "28662:7:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_uint256",
+                      "typeString": "uint256"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                }
+              ],
+              "src": "28646:32:1"
+            },
+            "returnParameters": {
+              "id": 1115,
+              "nodeType": "ParameterList",
+              "parameters": [],
+              "src": "28688:0:1"
+            },
+            "scope": 1302,
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+                            "typeDescriptions": {
+                              "typeIdentifier": "t_address",
+                              "typeString": "address"
+                            }
+                          },
+                          "isConstant": false,
+                          "isLValue": true,
+                          "isPure": false,
+                          "lValueRequested": false,
+                          "nodeType": "IndexAccess",
+                          "src": "31060:18:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_array$_t_uint256_$dyn_storage",
+                            "typeString": "uint256[] storage ref"
+                          }
+                        },
+                        "id": 1207,
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+                        "isLValue": true,
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+                        "lValueRequested": false,
+                        "memberName": "length",
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+                        "referencedDeclaration": null,
+                        "src": "31060:25:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      },
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+                      "lValueRequested": false,
+                      "memberName": "sub",
+                      "nodeType": "MemberAccess",
+                      "referencedDeclaration": 190,
+                      "src": "31060:29:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_function_internal_pure$_t_uint256_$_t_uint256_$returns$_t_uint256_$bound_to$_t_uint256_$",
+                        "typeString": "function (uint256,uint256) pure returns (uint256)"
+                      }
+                    },
+                    "id": 1210,
+                    "isConstant": false,
+                    "isLValue": false,
+                    "isPure": false,
+                    "kind": "functionCall",
+                    "lValueRequested": false,
+                    "names": [],
+                    "nodeType": "FunctionCall",
+                    "src": "31060:32:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_uint256",
+                      "typeString": "uint256"
+                    }
+                  },
+                  "nodeType": "VariableDeclarationStatement",
+                  "src": "31035:57:1"
+                },
+                {
+                  "assignments": [
+                    1213
+                  ],
+                  "declarations": [
+                    {
+                      "constant": false,
+                      "id": 1213,
+                      "name": "tokenIndex",
+                      "nodeType": "VariableDeclaration",
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+                      "src": "31102:18:1",
+                      "stateVariable": false,
+                      "storageLocation": "default",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_uint256",
+                        "typeString": "uint256"
+                      },
+                      "typeName": {
+                        "id": 1212,
+                        "name": "uint256",
+                        "nodeType": "ElementaryTypeName",
+                        "src": "31102:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      },
+                      "value": null,
+                      "visibility": "internal"
+                    }
+                  ],
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+                      "name": "_ownedTokensIndex",
+                      "nodeType": "Identifier",
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+                      "referencedDeclaration": 985,
+                      "src": "31123:17:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_mapping$_t_uint256_$_t_uint256_$",
+                        "typeString": "mapping(uint256 => uint256)"
+                      }
+                    },
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+                      "src": "31141:7:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_uint256",
+                        "typeString": "uint256"
+                      }
+                    },
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+                    "lValueRequested": false,
+                    "nodeType": "IndexAccess",
+                    "src": "31123:26:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_uint256",
+                      "typeString": "uint256"
+                    }
+                  },
+                  "nodeType": "VariableDeclarationStatement",
+                  "src": "31102:47:1"
+                },
+                {
+                  "condition": {
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+                    "commonType": {
+                      "typeIdentifier": "t_uint256",
+                      "typeString": "uint256"
+                    },
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+                      "referencedDeclaration": 1213,
+                      "src": "31253:10:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_uint256",
+                        "typeString": "uint256"
+                      }
+                    },
+                    "nodeType": "BinaryOperation",
+                    "operator": "!=",
+                    "rightExpression": {
+                      "argumentTypes": null,
+                      "id": 1219,
+                      "name": "lastTokenIndex",
+                      "nodeType": "Identifier",
+                      "overloadedDeclarations": [],
+                      "referencedDeclaration": 1203,
+                      "src": "31267:14:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_uint256",
+                        "typeString": "uint256"
+                      }
+                    },
+                    "src": "31253:28:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_bool",
+                      "typeString": "bool"
+                    }
+                  },
+                  "falseBody": null,
+                  "id": 1244,
+                  "nodeType": "IfStatement",
+                  "src": "31249:323:1",
+                  "trueBody": {
+                    "id": 1243,
+                    "nodeType": "Block",
+                    "src": "31283:289:1",
+                    "statements": [
+                      {
+                        "assignments": [
+                          1222
+                        ],
+                        "declarations": [
+                          {
+                            "constant": false,
+                            "id": 1222,
+                            "name": "lastTokenId",
+                            "nodeType": "VariableDeclaration",
+                            "scope": 1243,
+                            "src": "31297:19:1",
+                            "stateVariable": false,
+                            "storageLocation": "default",
+                            "typeDescriptions": {
+                              "typeIdentifier": "t_uint256",
+                              "typeString": "uint256"
+                            },
+                            "typeName": {
+                              "id": 1221,
+                              "name": "uint256",
+                              "nodeType": "ElementaryTypeName",
+                              "src": "31297:7:1",
+                              "typeDescriptions": {
+                                "typeIdentifier": "t_uint256",
+                                "typeString": "uint256"
+                              }
+                            },
+                            "value": null,
+                            "visibility": "internal"
+                          }
+                        ],
+                        "id": 1228,
+                        "initialValue": {
+                          "argumentTypes": null,
+                          "baseExpression": {
+                            "argumentTypes": null,
+                            "baseExpression": {
+                              "argumentTypes": null,
+                              "id": 1223,
+                              "name": "_ownedTokens",
+                              "nodeType": "Identifier",
+                              "overloadedDeclarations": [],
+                              "referencedDeclaration": 981,
+                              "src": "31319:12:1",
+                              "typeDescriptions": {
+                                "typeIdentifier": "t_mapping$_t_address_$_t_array$_t_uint256_$dyn_storage_$",
+                                "typeString": "mapping(address => uint256[] storage ref)"
+                              }
+                            },
+                            "id": 1225,
+                            "indexExpression": {
+                              "argumentTypes": null,
+                              "id": 1224,
+                              "name": "from",
+                              "nodeType": "Identifier",
+                              "overloadedDeclarations": [],
+                              "referencedDeclaration": 1197,
+                              "src": "31332:4:1",
+                              "typeDescriptions": {
+                                "typeIdentifier": "t_address",
+                                "typeString": "address"
+                              }
+                            },
+                            "isConstant": false,
+                            "isLValue": true,
+                            "isPure": false,
+                            "lValueRequested": false,
+                            "nodeType": "IndexAccess",
+                            "src": "31319:18:1",
+                            "typeDescriptions": {
+                              "typeIdentifier": "t_array$_t_uint256_$dyn_storage",
+                              "typeString": "uint256[] storage ref"
+                            }
+                          },
+                          "id": 1227,
+                          "indexExpression": {
+                            "argumentTypes": null,
+                            "id": 1226,
+                            "name": "lastTokenIndex",
+                            "nodeType": "Identifier",
+                            "overloadedDeclarations": [],
+                            "referencedDeclaration": 1203,
+                            "src": "31338:14:1",
+                            "typeDescriptions": {
+                              "typeIdentifier": "t_uint256",
+                              "typeString": "uint256"
+                            }
+                          },
+                          "isConstant": false,
+                          "isLValue": true,
+                          "isPure": false,
+                          "lValueRequested": false,
+                          "nodeType": "IndexAccess",
+                          "src": "31319:34:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_uint256",
+                            "typeString": "uint256"
+                          }
+                        },
+                        "nodeType": "VariableDeclarationStatement",
+                        "src": "31297:56:1"
+                      },
+                      {
+                        "expression": {
+                          "argumentTypes": null,
+                          "id": 1235,
+                          "isConstant": false,
+                          "isLValue": false,
+                          "isPure": false,
+                          "lValueRequested": false,
+                          "leftHandSide": {
+                            "argumentTypes": null,
+                            "baseExpression": {
+                              "argumentTypes": null,
+                              "baseExpression": {
+                                "argumentTypes": null,
+                                "id": 1229,
+                                "name": "_ownedTokens",
+                                "nodeType": "Identifier",
+                                "overloadedDeclarations": [],
+                                "referencedDeclaration": 981,
+                                "src": "31368:12:1",
+                                "typeDescriptions": {
+                                  "typeIdentifier": "t_mapping$_t_address_$_t_array$_t_uint256_$dyn_storage_$",
+                                  "typeString": "mapping(address => uint256[] storage ref)"
+                                }
+                              },
+                              "id": 1232,
+                              "indexExpression": {
+                                "argumentTypes": null,
+                                "id": 1230,
+                                "name": "from",
+                                "nodeType": "Identifier",
+                                "overloadedDeclarations": [],
+                                "referencedDeclaration": 1197,
+                                "src": "31381:4:1",
+                                "typeDescriptions": {
+                                  "typeIdentifier": "t_address",
+                                  "typeString": "address"
+                                }
+                              },
+                              "isConstant": false,
+                              "isLValue": true,
+                              "isPure": false,
+                              "lValueRequested": false,
+                              "nodeType": "IndexAccess",
+                              "src": "31368:18:1",
+                              "typeDescriptions": {
+                                "typeIdentifier": "t_array$_t_uint256_$dyn_storage",
+                                "typeString": "uint256[] storage ref"
+                              }
+                            },
+                            "id": 1233,
+                            "indexExpression": {
+                              "argumentTypes": null,
+                              "id": 1231,
+                              "name": "tokenIndex",
+                              "nodeType": "Identifier",
+                              "overloadedDeclarations": [],
+                              "referencedDeclaration": 1213,
+                              "src": "31387:10:1",
+                              "typeDescriptions": {
+                                "typeIdentifier": "t_uint256",
+                                "typeString": "uint256"
+                              }
+                            },
+                            "isConstant": false,
+                            "isLValue": true,
+                            "isPure": false,
+                            "lValueRequested": true,
+                            "nodeType": "IndexAccess",
+                            "src": "31368:30:1",
+                            "typeDescriptions": {
+                              "typeIdentifier": "t_uint256",
+                              "typeString": "uint256"
+                            }
+                          },
+                          "nodeType": "Assignment",
+                          "operator": "=",
+                          "rightHandSide": {
+                            "argumentTypes": null,
+                            "id": 1234,
+                            "name": "lastTokenId",
+                            "nodeType": "Identifier",
+                            "overloadedDeclarations": [],
+                            "referencedDeclaration": 1222,
+                            "src": "31401:11:1",
+                            "typeDescriptions": {
+                              "typeIdentifier": "t_uint256",
+                              "typeString": "uint256"
+                            }
+                          },
+                          "src": "31368:44:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_uint256",
+                            "typeString": "uint256"
+                          }
+                        },
+                        "id": 1236,
+                        "nodeType": "ExpressionStatement",
+                        "src": "31368:44:1"
+                      },
+                      {
+                        "expression": {
+                          "argumentTypes": null,
+                          "id": 1241,
+                          "isConstant": false,
+                          "isLValue": false,
+                          "isPure": false,
+                          "lValueRequested": false,
+                          "leftHandSide": {
+                            "argumentTypes": null,
+                            "baseExpression": {
+                              "argumentTypes": null,
+                              "id": 1237,
+                              "name": "_ownedTokensIndex",
+                              "nodeType": "Identifier",
+                              "overloadedDeclarations": [],
+                              "referencedDeclaration": 985,
+                              "src": "31484:17:1",
+                              "typeDescriptions": {
+                                "typeIdentifier": "t_mapping$_t_uint256_$_t_uint256_$",
+                                "typeString": "mapping(uint256 => uint256)"
+                              }
+                            },
+                            "id": 1239,
+                            "indexExpression": {
+                              "argumentTypes": null,
+                              "id": 1238,
+                              "name": "lastTokenId",
+                              "nodeType": "Identifier",
+                              "overloadedDeclarations": [],
+                              "referencedDeclaration": 1222,
+                              "src": "31502:11:1",
+                              "typeDescriptions": {
+                                "typeIdentifier": "t_uint256",
+                                "typeString": "uint256"
+                              }
+                            },
+                            "isConstant": false,
+                            "isLValue": true,
+                            "isPure": false,
+                            "lValueRequested": true,
+                            "nodeType": "IndexAccess",
+                            "src": "31484:30:1",
+                            "typeDescriptions": {
+                              "typeIdentifier": "t_uint256",
+                              "typeString": "uint256"
+                            }
+                          },
+                          "nodeType": "Assignment",
+                          "operator": "=",
+                          "rightHandSide": {
+                            "argumentTypes": null,
+                            "id": 1240,
+                            "name": "tokenIndex",
+                            "nodeType": "Identifier",
+                            "overloadedDeclarations": [],
+                            "referencedDeclaration": 1213,
+                            "src": "31517:10:1",
+                            "typeDescriptions": {
+                              "typeIdentifier": "t_uint256",
+                              "typeString": "uint256"
+                            }
+                          },
+                          "src": "31484:43:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_uint256",
+                            "typeString": "uint256"
+                          }
+                        },
+                        "id": 1242,
+                        "nodeType": "ExpressionStatement",
+                        "src": "31484:43:1"
+                      }
+                    ]
+                  }
+                },
+                {
+                  "expression": {
+                    "argumentTypes": null,
+                    "id": 1249,
+                    "isConstant": false,
+                    "isLValue": false,
+                    "isPure": false,
+                    "lValueRequested": false,
+                    "nodeType": "UnaryOperation",
+                    "operator": "--",
+                    "prefix": false,
+                    "src": "31658:27:1",
+                    "subExpression": {
+                      "argumentTypes": null,
+                      "expression": {
+                        "argumentTypes": null,
+                        "baseExpression": {
+                          "argumentTypes": null,
+                          "id": 1245,
+                          "name": "_ownedTokens",
+                          "nodeType": "Identifier",
+                          "overloadedDeclarations": [],
+                          "referencedDeclaration": 981,
+                          "src": "31658:12:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_mapping$_t_address_$_t_array$_t_uint256_$dyn_storage_$",
+                            "typeString": "mapping(address => uint256[] storage ref)"
+                          }
+                        },
+                        "id": 1247,
+                        "indexExpression": {
+                          "argumentTypes": null,
+                          "id": 1246,
+                          "name": "from",
+                          "nodeType": "Identifier",
+                          "overloadedDeclarations": [],
+                          "referencedDeclaration": 1197,
+                          "src": "31671:4:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_address",
+                            "typeString": "address"
+                          }
+                        },
+                        "isConstant": false,
+                        "isLValue": true,
+                        "isPure": false,
+                        "lValueRequested": false,
+                        "nodeType": "IndexAccess",
+                        "src": "31658:18:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_array$_t_uint256_$dyn_storage",
+                          "typeString": "uint256[] storage ref"
+                        }
+                      },
+                      "id": 1248,
+                      "isConstant": false,
+                      "isLValue": true,
+                      "isPure": false,
+                      "lValueRequested": true,
+                      "memberName": "length",
+                      "nodeType": "MemberAccess",
+                      "referencedDeclaration": null,
+                      "src": "31658:25:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_uint256",
+                        "typeString": "uint256"
+                      }
+                    },
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_uint256",
+                      "typeString": "uint256"
+                    }
+                  },
+                  "id": 1250,
+                  "nodeType": "ExpressionStatement",
+                  "src": "31658:27:1"
+                }
+              ]
+            },
+            "documentation": "@dev Private function to remove a token from this extension's ownership-tracking data structures. Note that\nwhile the token is not assigned a new owner, the _ownedTokensIndex mapping is _not_ updated: this allows for\ngas optimizations e.g. when performing a transfer operation (avoiding double writes).\nThis has O(1) time complexity, but alters the order of the _ownedTokens array.\n@param from address representing the previous owner of the given token ID\n@param tokenId uint256 ID of the token to be removed from the tokens list of the given address",
+            "id": 1252,
+            "implemented": true,
+            "kind": "function",
+            "modifiers": [],
+            "name": "_removeTokenFromOwnerEnumeration",
+            "nodeType": "FunctionDefinition",
+            "parameters": {
+              "id": 1200,
+              "nodeType": "ParameterList",
+              "parameters": [
+                {
+                  "constant": false,
+                  "id": 1197,
+                  "name": "from",
+                  "nodeType": "VariableDeclaration",
+                  "scope": 1252,
+                  "src": "30815:12:1",
+                  "stateVariable": false,
+                  "storageLocation": "default",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_address",
+                    "typeString": "address"
+                  },
+                  "typeName": {
+                    "id": 1196,
+                    "name": "address",
+                    "nodeType": "ElementaryTypeName",
+                    "src": "30815:7:1",
+                    "stateMutability": "nonpayable",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_address",
+                      "typeString": "address"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                },
+                {
+                  "constant": false,
+                  "id": 1199,
+                  "name": "tokenId",
+                  "nodeType": "VariableDeclaration",
+                  "scope": 1252,
+                  "src": "30829:15:1",
+                  "stateVariable": false,
+                  "storageLocation": "default",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_uint256",
+                    "typeString": "uint256"
+                  },
+                  "typeName": {
+                    "id": 1198,
+                    "name": "uint256",
+                    "nodeType": "ElementaryTypeName",
+                    "src": "30829:7:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_uint256",
+                      "typeString": "uint256"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                }
+              ],
+              "src": "30814:31:1"
+            },
+            "returnParameters": {
+              "id": 1201,
+              "nodeType": "ParameterList",
+              "parameters": [],
+              "src": "30854:0:1"
+            },
+            "scope": 1302,
+            "src": "30773:1128:1",
+            "stateMutability": "nonpayable",
+            "superFunction": null,
+            "visibility": "private"
+          },
+          {
+            "body": {
+              "id": 1300,
+              "nodeType": "Block",
+              "src": "32260:993:1",
+              "statements": [
+                {
+                  "assignments": [
+                    1258
+                  ],
+                  "declarations": [
+                    {
+                      "constant": false,
+                      "id": 1258,
+                      "name": "lastTokenIndex",
+                      "nodeType": "VariableDeclaration",
+                      "scope": 1300,
+                      "src": "32438:22:1",
+                      "stateVariable": false,
+                      "storageLocation": "default",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_uint256",
+                        "typeString": "uint256"
+                      },
+                      "typeName": {
+                        "id": 1257,
+                        "name": "uint256",
+                        "nodeType": "ElementaryTypeName",
+                        "src": "32438:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      },
+                      "value": null,
+                      "visibility": "internal"
+                    }
+                  ],
+                  "id": 1264,
+                  "initialValue": {
+                    "argumentTypes": null,
+                    "arguments": [
+                      {
+                        "argumentTypes": null,
+                        "hexValue": "31",
+                        "id": 1262,
+                        "isConstant": false,
+                        "isLValue": false,
+                        "isPure": true,
+                        "kind": "number",
+                        "lValueRequested": false,
+                        "nodeType": "Literal",
+                        "src": "32485:1:1",
+                        "subdenomination": null,
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_rational_1_by_1",
+                          "typeString": "int_const 1"
+                        },
+                        "value": "1"
+                      }
+                    ],
+                    "expression": {
+                      "argumentTypes": [
+                        {
+                          "typeIdentifier": "t_rational_1_by_1",
+                          "typeString": "int_const 1"
+                        }
+                      ],
+                      "expression": {
+                        "argumentTypes": null,
+                        "expression": {
+                          "argumentTypes": null,
+                          "id": 1259,
+                          "name": "_allTokens",
+                          "nodeType": "Identifier",
+                          "overloadedDeclarations": [],
+                          "referencedDeclaration": 988,
+                          "src": "32463:10:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_array$_t_uint256_$dyn_storage",
+                            "typeString": "uint256[] storage ref"
+                          }
+                        },
+                        "id": 1260,
+                        "isConstant": false,
+                        "isLValue": true,
+                        "isPure": false,
+                        "lValueRequested": false,
+                        "memberName": "length",
+                        "nodeType": "MemberAccess",
+                        "referencedDeclaration": null,
+                        "src": "32463:17:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      },
+                      "id": 1261,
+                      "isConstant": false,
+                      "isLValue": false,
+                      "isPure": false,
+                      "lValueRequested": false,
+                      "memberName": "sub",
+                      "nodeType": "MemberAccess",
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+                        "src": "36290:5:1",
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+                        "src": "36278:5:1",
+                        "typeDescriptions": {
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+                              "nodeType": "Identifier",
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+                              "src": "36416:10:1",
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+                              "src": "36427:7:1",
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+                    "name": "address",
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+                  "visibility": "internal"
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+            "src": "36212:240:1",
+            "stateMutability": "nonpayable",
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+        "src": "33817:2637:1"
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+        "literals": [
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+          "^",
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+          ".0"
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+        "nodeType": "PragmaDirective",
+        "src": "36518:23:1"
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+            "baseName": {
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+              "id": 1450,
+              "name": "ERC721",
+              "nodeType": "UserDefinedTypeName",
+              "referencedDeclaration": 944,
+              "src": "36838:6:1",
+              "typeDescriptions": {
+                "typeIdentifier": "t_contract$_ERC721_$944",
+                "typeString": "contract ERC721"
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+            "nodeType": "InheritanceSpecifier",
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+              "nodeType": "UserDefinedTypeName",
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+              "src": "36846:16:1",
+              "typeDescriptions": {
+                "typeIdentifier": "t_contract$_ERC721Enumerable_$1302",
+                "typeString": "contract ERC721Enumerable"
+              }
+            },
+            "id": 1453,
+            "nodeType": "InheritanceSpecifier",
+            "src": "36846:16:1"
+          },
+          {
+            "arguments": null,
+            "baseName": {
+              "contractScope": null,
+              "id": 1454,
+              "name": "ERC721Metadata",
+              "nodeType": "UserDefinedTypeName",
+              "referencedDeclaration": 1448,
+              "src": "36864:14:1",
+              "typeDescriptions": {
+                "typeIdentifier": "t_contract$_ERC721Metadata_$1448",
+                "typeString": "contract ERC721Metadata"
+              }
+            },
+            "id": 1455,
+            "nodeType": "InheritanceSpecifier",
+            "src": "36864:14:1"
+          }
+        ],
+        "contractDependencies": [
+          944,
+          969,
+          23,
+          124,
+          386,
+          1302,
+          1323,
+          1448
+        ],
+        "contractKind": "contract",
+        "documentation": "@title Full ERC721 Token\nThis implementation includes all the required and some optional functionality of the ERC721 standard\nMoreover, it includes approve all functionality using operator terminology\n@dev see https://eips.ethereum.org/EIPS/eip-721",
+        "fullyImplemented": true,
+        "id": 1468,
+        "linearizedBaseContracts": [
+          1468,
+          1448,
+          1323,
+          1302,
+          969,
+          944,
+          124,
+          386,
+          23
+        ],
+        "name": "ERC721Full",
+        "nodeType": "ContractDefinition",
+        "nodes": [
+          {
+            "body": {
+              "id": 1466,
+              "nodeType": "Block",
+              "src": "36976:64:1",
+              "statements": []
+            },
+            "documentation": null,
+            "id": 1467,
+            "implemented": true,
+            "kind": "constructor",
+            "modifiers": [
+              {
+                "arguments": [
+                  {
+                    "argumentTypes": null,
+                    "id": 1462,
+                    "name": "name",
+                    "nodeType": "Identifier",
+                    "overloadedDeclarations": [],
+                    "referencedDeclaration": 1457,
+                    "src": "36962:4:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_string_memory_ptr",
+                      "typeString": "string memory"
+                    }
+                  },
+                  {
+                    "argumentTypes": null,
+                    "id": 1463,
+                    "name": "symbol",
+                    "nodeType": "Identifier",
+                    "overloadedDeclarations": [],
+                    "referencedDeclaration": 1459,
+                    "src": "36968:6:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_string_memory_ptr",
+                      "typeString": "string memory"
+                    }
+                  }
+                ],
+                "id": 1464,
+                "modifierName": {
+                  "argumentTypes": null,
+                  "id": 1461,
+                  "name": "ERC721Metadata",
+                  "nodeType": "Identifier",
+                  "overloadedDeclarations": [],
+                  "referencedDeclaration": 1448,
+                  "src": "36947:14:1",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_type$_t_contract$_ERC721Metadata_$1448_$",
+                    "typeString": "type(contract ERC721Metadata)"
+                  }
+                },
+                "nodeType": "ModifierInvocation",
+                "src": "36947:28:1"
+              }
+            ],
+            "name": "",
+            "nodeType": "FunctionDefinition",
+            "parameters": {
+              "id": 1460,
+              "nodeType": "ParameterList",
+              "parameters": [
+                {
+                  "constant": false,
+                  "id": 1457,
+                  "name": "name",
+                  "nodeType": "VariableDeclaration",
+                  "scope": 1467,
+                  "src": "36898:18:1",
+                  "stateVariable": false,
+                  "storageLocation": "memory",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_string_memory_ptr",
+                    "typeString": "string"
+                  },
+                  "typeName": {
+                    "id": 1456,
+                    "name": "string",
+                    "nodeType": "ElementaryTypeName",
+                    "src": "36898:6:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_string_storage_ptr",
+                      "typeString": "string"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                },
+                {
+                  "constant": false,
+                  "id": 1459,
+                  "name": "symbol",
+                  "nodeType": "VariableDeclaration",
+                  "scope": 1467,
+                  "src": "36918:20:1",
+                  "stateVariable": false,
+                  "storageLocation": "memory",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_string_memory_ptr",
+                    "typeString": "string"
+                  },
+                  "typeName": {
+                    "id": 1458,
+                    "name": "string",
+                    "nodeType": "ElementaryTypeName",
+                    "src": "36918:6:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_string_storage_ptr",
+                      "typeString": "string"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                }
+              ],
+              "src": "36897:42:1"
+            },
+            "returnParameters": {
+              "id": 1465,
+              "nodeType": "ParameterList",
+              "parameters": [],
+              "src": "36976:0:1"
+            },
+            "scope": 1468,
+            "src": "36885:155:1",
+            "stateMutability": "nonpayable",
+            "superFunction": null,
+            "visibility": "public"
+          }
+        ],
+        "scope": 1469,
+        "src": "36815:227:1"
+      }
+    ],
+    "src": "61:36982:1"
+  },
+  "compiler": {
+    "name": "solc",
+    "version": "0.5.0+commit.1d4f565a.Emscripten.clang"
+  },
+  "networks": {},
+  "schemaVersion": "3.0.2",
+  "updatedAt": "2019-09-05T15:01:08.667Z",
+  "devdoc": {
+    "details": "see https://eips.ethereum.org/EIPS/eip-721",
+    "methods": {
+      "approve(address,uint256)": {
+        "details": "Approves another address to transfer the given token ID The zero address indicates there is no approved address. There can only be one approved address per token at a given time. Can only be called by the token owner or an approved operator.",
+        "params": {
+          "to": "address to be approved for the given token ID",
+          "tokenId": "uint256 ID of the token to be approved"
+        }
+      },
+      "balanceOf(address)": {
+        "details": "Gets the balance of the specified address.",
+        "params": {
+          "owner": "address to query the balance of"
+        },
+        "return": "uint256 representing the amount owned by the passed address"
+      },
+      "getApproved(uint256)": {
+        "details": "Gets the approved address for a token ID, or zero if no address set Reverts if the token ID does not exist.",
+        "params": {
+          "tokenId": "uint256 ID of the token to query the approval of"
+        },
+        "return": "address currently approved for the given token ID"
+      },
+      "isApprovedForAll(address,address)": {
+        "details": "Tells whether an operator is approved by a given owner.",
+        "params": {
+          "operator": "operator address which you want to query the approval of",
+          "owner": "owner address which you want to query the approval of"
+        },
+        "return": "bool whether the given operator is approved by the given owner"
+      },
+      "name()": {
+        "details": "Gets the token name.",
+        "return": "string representing the token name"
+      },
+      "ownerOf(uint256)": {
+        "details": "Gets the owner of the specified token ID.",
+        "params": {
+          "tokenId": "uint256 ID of the token to query the owner of"
+        },
+        "return": "address currently marked as the owner of the given token ID"
+      },
+      "safeTransferFrom(address,address,uint256)": {
+        "details": "Safely transfers the ownership of a given token ID to another address If the target address is a contract, it must implement `onERC721Received`, which is called upon a safe transfer, and return the magic value `bytes4(keccak256(\"onERC721Received(address,address,uint256,bytes)\"))`; otherwise, the transfer is reverted. Requires the msg.sender to be the owner, approved, or operator",
+        "params": {
+          "from": "current owner of the token",
+          "to": "address to receive the ownership of the given token ID",
+          "tokenId": "uint256 ID of the token to be transferred"
+        }
+      },
+      "safeTransferFrom(address,address,uint256,bytes)": {
+        "details": "Safely transfers the ownership of a given token ID to another address If the target address is a contract, it must implement `onERC721Received`, which is called upon a safe transfer, and return the magic value `bytes4(keccak256(\"onERC721Received(address,address,uint256,bytes)\"))`; otherwise, the transfer is reverted. Requires the msg.sender to be the owner, approved, or operator",
+        "params": {
+          "_data": "bytes data to send along with a safe transfer check",
+          "from": "current owner of the token",
+          "to": "address to receive the ownership of the given token ID",
+          "tokenId": "uint256 ID of the token to be transferred"
+        }
+      },
+      "setApprovalForAll(address,bool)": {
+        "details": "Sets or unsets the approval of a given operator An operator is allowed to transfer all tokens of the sender on their behalf.",
+        "params": {
+          "approved": "representing the status of the approval to be set",
+          "to": "operator address to set the approval"
+        }
+      },
+      "supportsInterface(bytes4)": {
+        "details": "See `IERC165.supportsInterface`.     * Time complexity O(1), guaranteed to always use less than 30 000 gas."
+      },
+      "symbol()": {
+        "details": "Gets the token symbol.",
+        "return": "string representing the token symbol"
+      },
+      "tokenByIndex(uint256)": {
+        "details": "Gets the token ID at a given index of all the tokens in this contract Reverts if the index is greater or equal to the total number of tokens.",
+        "params": {
+          "index": "uint256 representing the index to be accessed of the tokens list"
+        },
+        "return": "uint256 token ID at the given index of the tokens list"
+      },
+      "tokenOfOwnerByIndex(address,uint256)": {
+        "details": "Gets the token ID at a given index of the tokens list of the requested owner.",
+        "params": {
+          "index": "uint256 representing the index to be accessed of the requested tokens list",
+          "owner": "address owning the tokens list to be accessed"
+        },
+        "return": "uint256 token ID at the given index of the tokens list owned by the requested address"
+      },
+      "tokenURI(uint256)": {
+        "details": "Returns an URI for a given token ID. Throws if the token ID does not exist. May return an empty string.",
+        "params": {
+          "tokenId": "uint256 ID of the token to query"
+        }
+      },
+      "totalSupply()": {
+        "details": "Gets the total amount of tokens stored by the contract.",
+        "return": "uint256 representing the total amount of tokens"
+      },
+      "transferFrom(address,address,uint256)": {
+        "details": "Transfers the ownership of a given token ID to another address. Usage of this method is discouraged, use `safeTransferFrom` whenever possible. Requires the msg.sender to be the owner, approved, or operator.",
+        "params": {
+          "from": "current owner of the token",
+          "to": "address to receive the ownership of the given token ID",
+          "tokenId": "uint256 ID of the token to be transferred"
+        }
+      }
+    },
+    "title": "Full ERC721 Token This implementation includes all the required and some optional functionality of the ERC721 standard Moreover, it includes approve all functionality using operator terminology"
+  },
+  "userdoc": {
+    "methods": {}
+  }
+}
\ No newline at end of file
diff --git a/src/abis/ERC721Metadata.json b/src/abis/ERC721Metadata.json
new file mode 100644
index 0000000..88250d7
--- /dev/null
+++ b/src/abis/ERC721Metadata.json
@@ -0,0 +1,37870 @@
+{
+  "contractName": "ERC721Metadata",
+  "abi": [
+    {
+      "constant": true,
+      "inputs": [
+        {
+          "name": "interfaceId",
+          "type": "bytes4"
+        }
+      ],
+      "name": "supportsInterface",
+      "outputs": [
+        {
+          "name": "",
+          "type": "bool"
+        }
+      ],
+      "payable": false,
+      "stateMutability": "view",
+      "type": "function"
+    },
+    {
+      "constant": true,
+      "inputs": [
+        {
+          "name": "tokenId",
+          "type": "uint256"
+        }
+      ],
+      "name": "getApproved",
+      "outputs": [
+        {
+          "name": "",
+          "type": "address"
+        }
+      ],
+      "payable": false,
+      "stateMutability": "view",
+      "type": "function"
+    },
+    {
+      "constant": false,
+      "inputs": [
+        {
+          "name": "to",
+          "type": "address"
+        },
+        {
+          "name": "tokenId",
+          "type": "uint256"
+        }
+      ],
+      "name": "approve",
+      "outputs": [],
+      "payable": false,
+      "stateMutability": "nonpayable",
+      "type": "function"
+    },
+    {
+      "constant": false,
+      "inputs": [
+        {
+          "name": "from",
+          "type": "address"
+        },
+        {
+          "name": "to",
+          "type": "address"
+        },
+        {
+          "name": "tokenId",
+          "type": "uint256"
+        }
+      ],
+      "name": "transferFrom",
+      "outputs": [],
+      "payable": false,
+      "stateMutability": "nonpayable",
+      "type": "function"
+    },
+    {
+      "constant": false,
+      "inputs": [
+        {
+          "name": "from",
+          "type": "address"
+        },
+        {
+          "name": "to",
+          "type": "address"
+        },
+        {
+          "name": "tokenId",
+          "type": "uint256"
+        }
+      ],
+      "name": "safeTransferFrom",
+      "outputs": [],
+      "payable": false,
+      "stateMutability": "nonpayable",
+      "type": "function"
+    },
+    {
+      "constant": true,
+      "inputs": [
+        {
+          "name": "tokenId",
+          "type": "uint256"
+        }
+      ],
+      "name": "ownerOf",
+      "outputs": [
+        {
+          "name": "",
+          "type": "address"
+        }
+      ],
+      "payable": false,
+      "stateMutability": "view",
+      "type": "function"
+    },
+    {
+      "constant": true,
+      "inputs": [
+        {
+          "name": "owner",
+          "type": "address"
+        }
+      ],
+      "name": "balanceOf",
+      "outputs": [
+        {
+          "name": "",
+          "type": "uint256"
+        }
+      ],
+      "payable": false,
+      "stateMutability": "view",
+      "type": "function"
+    },
+    {
+      "constant": false,
+      "inputs": [
+        {
+          "name": "to",
+          "type": "address"
+        },
+        {
+          "name": "approved",
+          "type": "bool"
+        }
+      ],
+      "name": "setApprovalForAll",
+      "outputs": [],
+      "payable": false,
+      "stateMutability": "nonpayable",
+      "type": "function"
+    },
+    {
+      "constant": false,
+      "inputs": [
+        {
+          "name": "from",
+          "type": "address"
+        },
+        {
+          "name": "to",
+          "type": "address"
+        },
+        {
+          "name": "tokenId",
+          "type": "uint256"
+        },
+        {
+          "name": "_data",
+          "type": "bytes"
+        }
+      ],
+      "name": "safeTransferFrom",
+      "outputs": [],
+      "payable": false,
+      "stateMutability": "nonpayable",
+      "type": "function"
+    },
+    {
+      "constant": true,
+      "inputs": [
+        {
+          "name": "owner",
+          "type": "address"
+        },
+        {
+          "name": "operator",
+          "type": "address"
+        }
+      ],
+      "name": "isApprovedForAll",
+      "outputs": [
+        {
+          "name": "",
+          "type": "bool"
+        }
+      ],
+      "payable": false,
+      "stateMutability": "view",
+      "type": "function"
+    },
+    {
+      "inputs": [
+        {
+          "name": "name",
+          "type": "string"
+        },
+        {
+          "name": "symbol",
+          "type": "string"
+        }
+      ],
+      "payable": false,
+      "stateMutability": "nonpayable",
+      "type": "constructor"
+    },
+    {
+      "anonymous": false,
+      "inputs": [
+        {
+          "indexed": true,
+          "name": "from",
+          "type": "address"
+        },
+        {
+          "indexed": true,
+          "name": "to",
+          "type": "address"
+        },
+        {
+          "indexed": true,
+          "name": "tokenId",
+          "type": "uint256"
+        }
+      ],
+      "name": "Transfer",
+      "type": "event"
+    },
+    {
+      "anonymous": false,
+      "inputs": [
+        {
+          "indexed": true,
+          "name": "owner",
+          "type": "address"
+        },
+        {
+          "indexed": true,
+          "name": "approved",
+          "type": "address"
+        },
+        {
+          "indexed": true,
+          "name": "tokenId",
+          "type": "uint256"
+        }
+      ],
+      "name": "Approval",
+      "type": "event"
+    },
+    {
+      "anonymous": false,
+      "inputs": [
+        {
+          "indexed": true,
+          "name": "owner",
+          "type": "address"
+        },
+        {
+          "indexed": true,
+          "name": "operator",
+          "type": "address"
+        },
+        {
+          "indexed": false,
+          "name": "approved",
+          "type": "bool"
+        }
+      ],
+      "name": "ApprovalForAll",
+      "type": "event"
+    },
+    {
+      "constant": true,
+      "inputs": [],
+      "name": "name",
+      "outputs": [
+        {
+          "name": "",
+          "type": "string"
+        }
+      ],
+      "payable": false,
+      "stateMutability": "view",
+      "type": "function"
+    },
+    {
+      "constant": true,
+      "inputs": [],
+      "name": "symbol",
+      "outputs": [
+        {
+          "name": "",
+          "type": "string"
+        }
+      ],
+      "payable": false,
+      "stateMutability": "view",
+      "type": "function"
+    },
+    {
+      "constant": true,
+      "inputs": [
+        {
+          "name": "tokenId",
+          "type": "uint256"
+        }
+      ],
+      "name": "tokenURI",
+      "outputs": [
+        {
+          "name": "",
+          "type": "string"
+        }
+      ],
+      "payable": false,
+      "stateMutability": "view",
+      "type": "function"
+    }
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+  "source": "\n// File: @openzeppelin/contracts/introspection/IERC165.sol\n\npragma solidity ^0.5.0;\n\n/**\n * @dev Interface of the ERC165 standard, as defined in the\n * [EIP](https://eips.ethereum.org/EIPS/eip-165).\n *\n * Implementers can declare support of contract interfaces, which can then be\n * queried by others (`ERC165Checker`).\n *\n * For an implementation, see `ERC165`.\n */\ninterface IERC165 {\n    /**\n     * @dev Returns true if this contract implements the interface defined by\n     * `interfaceId`. See the corresponding\n     * [EIP section](https://eips.ethereum.org/EIPS/eip-165#how-interfaces-are-identified)\n     * to learn more about how these ids are created.\n     *\n     * This function call must use less than 30 000 gas.\n     */\n    function supportsInterface(bytes4 interfaceId) external view returns (bool);\n}\n\n// File: @openzeppelin/contracts/token/ERC721/IERC721.sol\n\npragma solidity ^0.5.0;\n\n\n/**\n * @dev Required interface of an ERC721 compliant contract.\n */\ncontract IERC721 is IERC165 {\n    event Transfer(address indexed from, address indexed to, uint256 indexed tokenId);\n    event Approval(address indexed owner, address indexed approved, uint256 indexed tokenId);\n    event ApprovalForAll(address indexed owner, address indexed operator, bool approved);\n\n    /**\n     * @dev Returns the number of NFTs in `owner`'s account.\n     */\n    function balanceOf(address owner) public view returns (uint256 balance);\n\n    /**\n     * @dev Returns the owner of the NFT specified by `tokenId`.\n     */\n    function ownerOf(uint256 tokenId) public view returns (address owner);\n\n    /**\n     * @dev Transfers a specific NFT (`tokenId`) from one account (`from`) to\n     * another (`to`).\n     *\n     * \n     *\n     * Requirements:\n     * - `from`, `to` cannot be zero.\n     * - `tokenId` must be owned by `from`.\n     * - If the caller is not `from`, it must be have been allowed to move this\n     * NFT by either `approve` or `setApproveForAll`.\n     */\n    function safeTransferFrom(address from, address to, uint256 tokenId) public;\n    /**\n     * @dev Transfers a specific NFT (`tokenId`) from one account (`from`) to\n     * another (`to`).\n     *\n     * Requirements:\n     * - If the caller is not `from`, it must be approved to move this NFT by\n     * either `approve` or `setApproveForAll`.\n     */\n    function transferFrom(address from, address to, uint256 tokenId) public;\n    function approve(address to, uint256 tokenId) public;\n    function getApproved(uint256 tokenId) public view returns (address operator);\n\n    function setApprovalForAll(address operator, bool _approved) public;\n    function isApprovedForAll(address owner, address operator) public view returns (bool);\n\n\n    function safeTransferFrom(address from, address to, uint256 tokenId, bytes memory data) public;\n}\n\n// File: @openzeppelin/contracts/token/ERC721/IERC721Receiver.sol\n\npragma solidity ^0.5.0;\n\n/**\n * @title ERC721 token receiver interface\n * @dev Interface for any contract that wants to support safeTransfers\n * from ERC721 asset contracts.\n */\ncontract IERC721Receiver {\n    /**\n     * @notice Handle the receipt of an NFT\n     * @dev The ERC721 smart contract calls this function on the recipient\n     * after a `safeTransfer`. This function MUST return the function selector,\n     * otherwise the caller will revert the transaction. The selector to be\n     * returned can be obtained as `this.onERC721Received.selector`. This\n     * function MAY throw to revert and reject the transfer.\n     * Note: the ERC721 contract address is always the message sender.\n     * @param operator The address which called `safeTransferFrom` function\n     * @param from The address which previously owned the token\n     * @param tokenId The NFT identifier which is being transferred\n     * @param data Additional data with no specified format\n     * @return bytes4 `bytes4(keccak256(\"onERC721Received(address,address,uint256,bytes)\"))`\n     */\n    function onERC721Received(address operator, address from, uint256 tokenId, bytes memory data)\n    public returns (bytes4);\n}\n\n// File: @openzeppelin/contracts/math/SafeMath.sol\n\npragma solidity ^0.5.0;\n\n/**\n * @dev Wrappers over Solidity's arithmetic operations with added overflow\n * checks.\n *\n * Arithmetic operations in Solidity wrap on overflow. This can easily result\n * in bugs, because programmers usually assume that an overflow raises an\n * error, which is the standard behavior in high level programming languages.\n * `SafeMath` restores this intuition by reverting the transaction when an\n * operation overflows.\n *\n * Using this library instead of the unchecked operations eliminates an entire\n * class of bugs, so it's recommended to use it always.\n */\nlibrary SafeMath {\n    /**\n     * @dev Returns the addition of two unsigned integers, reverting on\n     * overflow.\n     *\n     * Counterpart to Solidity's `+` operator.\n     *\n     * Requirements:\n     * - Addition cannot overflow.\n     */\n    function add(uint256 a, uint256 b) internal pure returns (uint256) {\n        uint256 c = a + b;\n        require(c >= a, \"SafeMath: addition overflow\");\n\n        return c;\n    }\n\n    /**\n     * @dev Returns the subtraction of two unsigned integers, reverting on\n     * overflow (when the result is negative).\n     *\n     * Counterpart to Solidity's `-` operator.\n     *\n     * Requirements:\n     * - Subtraction cannot overflow.\n     */\n    function sub(uint256 a, uint256 b) internal pure returns (uint256) {\n        require(b <= a, \"SafeMath: subtraction overflow\");\n        uint256 c = a - b;\n\n        return c;\n    }\n\n    /**\n     * @dev Returns the multiplication of two unsigned integers, reverting on\n     * overflow.\n     *\n     * Counterpart to Solidity's `*` operator.\n     *\n     * Requirements:\n     * - Multiplication cannot overflow.\n     */\n    function mul(uint256 a, uint256 b) internal pure returns (uint256) {\n        // Gas optimization: this is cheaper than requiring 'a' not being zero, but the\n        // benefit is lost if 'b' is also tested.\n        // See: https://github.com/OpenZeppelin/openzeppelin-contracts/pull/522\n        if (a == 0) {\n            return 0;\n        }\n\n        uint256 c = a * b;\n        require(c / a == b, \"SafeMath: multiplication overflow\");\n\n        return c;\n    }\n\n    /**\n     * @dev Returns the integer division of two unsigned integers. Reverts on\n     * division by zero. The result is rounded towards zero.\n     *\n     * Counterpart to Solidity's `/` operator. Note: this function uses a\n     * `revert` opcode (which leaves remaining gas untouched) while Solidity\n     * uses an invalid opcode to revert (consuming all remaining gas).\n     *\n     * Requirements:\n     * - The divisor cannot be zero.\n     */\n    function div(uint256 a, uint256 b) internal pure returns (uint256) {\n        // Solidity only automatically asserts when dividing by 0\n        require(b > 0, \"SafeMath: division by zero\");\n        uint256 c = a / b;\n        // assert(a == b * c + a % b); // There is no case in which this doesn't hold\n\n        return c;\n    }\n\n    /**\n     * @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo),\n     * Reverts when dividing by zero.\n     *\n     * Counterpart to Solidity's `%` operator. This function uses a `revert`\n     * opcode (which leaves remaining gas untouched) while Solidity uses an\n     * invalid opcode to revert (consuming all remaining gas).\n     *\n     * Requirements:\n     * - The divisor cannot be zero.\n     */\n    function mod(uint256 a, uint256 b) internal pure returns (uint256) {\n        require(b != 0, \"SafeMath: modulo by zero\");\n        return a % b;\n    }\n}\n\n// File: @openzeppelin/contracts/utils/Address.sol\n\npragma solidity ^0.5.0;\n\n/**\n * @dev Collection of functions related to the address type,\n */\nlibrary Address {\n    /**\n     * @dev Returns true if `account` is a contract.\n     *\n     * This test is non-exhaustive, and there may be false-negatives: during the\n     * execution of a contract's constructor, its address will be reported as\n     * not containing a contract.\n     *\n     * > It is unsafe to assume that an address for which this function returns\n     * false is an externally-owned account (EOA) and not a contract.\n     */\n    function isContract(address account) internal view returns (bool) {\n        // This method relies in extcodesize, which returns 0 for contracts in\n        // construction, since the code is only stored at the end of the\n        // constructor execution.\n\n        uint256 size;\n        // solhint-disable-next-line no-inline-assembly\n        assembly { size := extcodesize(account) }\n        return size > 0;\n    }\n}\n\n// File: @openzeppelin/contracts/drafts/Counters.sol\n\npragma solidity ^0.5.0;\n\n\n/**\n * @title Counters\n * @author Matt Condon (@shrugs)\n * @dev Provides counters that can only be incremented or decremented by one. This can be used e.g. to track the number\n * of elements in a mapping, issuing ERC721 ids, or counting request ids.\n *\n * Include with `using Counters for Counters.Counter;`\n * Since it is not possible to overflow a 256 bit integer with increments of one, `increment` can skip the SafeMath\n * overflow check, thereby saving gas. This does assume however correct usage, in that the underlying `_value` is never\n * directly accessed.\n */\nlibrary Counters {\n    using SafeMath for uint256;\n\n    struct Counter {\n        // This variable should never be directly accessed by users of the library: interactions must be restricted to\n        // the library's function. As of Solidity v0.5.2, this cannot be enforced, though there is a proposal to add\n        // this feature: see https://github.com/ethereum/solidity/issues/4637\n        uint256 _value; // default: 0\n    }\n\n    function current(Counter storage counter) internal view returns (uint256) {\n        return counter._value;\n    }\n\n    function increment(Counter storage counter) internal {\n        counter._value += 1;\n    }\n\n    function decrement(Counter storage counter) internal {\n        counter._value = counter._value.sub(1);\n    }\n}\n\n// File: @openzeppelin/contracts/introspection/ERC165.sol\n\npragma solidity ^0.5.0;\n\n\n/**\n * @dev Implementation of the `IERC165` interface.\n *\n * Contracts may inherit from this and call `_registerInterface` to declare\n * their support of an interface.\n */\ncontract ERC165 is IERC165 {\n    /*\n     * bytes4(keccak256('supportsInterface(bytes4)')) == 0x01ffc9a7\n     */\n    bytes4 private constant _INTERFACE_ID_ERC165 = 0x01ffc9a7;\n\n    /**\n     * @dev Mapping of interface ids to whether or not it's supported.\n     */\n    mapping(bytes4 => bool) private _supportedInterfaces;\n\n    constructor () internal {\n        // Derived contracts need only register support for their own interfaces,\n        // we register support for ERC165 itself here\n        _registerInterface(_INTERFACE_ID_ERC165);\n    }\n\n    /**\n     * @dev See `IERC165.supportsInterface`.\n     *\n     * Time complexity O(1), guaranteed to always use less than 30 000 gas.\n     */\n    function supportsInterface(bytes4 interfaceId) external view returns (bool) {\n        return _supportedInterfaces[interfaceId];\n    }\n\n    /**\n     * @dev Registers the contract as an implementer of the interface defined by\n     * `interfaceId`. Support of the actual ERC165 interface is automatic and\n     * registering its interface id is not required.\n     *\n     * See `IERC165.supportsInterface`.\n     *\n     * Requirements:\n     *\n     * - `interfaceId` cannot be the ERC165 invalid interface (`0xffffffff`).\n     */\n    function _registerInterface(bytes4 interfaceId) internal {\n        require(interfaceId != 0xffffffff, \"ERC165: invalid interface id\");\n        _supportedInterfaces[interfaceId] = true;\n    }\n}\n\n// File: @openzeppelin/contracts/token/ERC721/ERC721.sol\n\npragma solidity ^0.5.0;\n\n\n\n\n\n\n\n/**\n * @title ERC721 Non-Fungible Token Standard basic implementation\n * @dev see https://eips.ethereum.org/EIPS/eip-721\n */\ncontract ERC721 is ERC165, IERC721 {\n    using SafeMath for uint256;\n    using Address for address;\n    using Counters for Counters.Counter;\n\n    // Equals to `bytes4(keccak256(\"onERC721Received(address,address,uint256,bytes)\"))`\n    // which can be also obtained as `IERC721Receiver(0).onERC721Received.selector`\n    bytes4 private constant _ERC721_RECEIVED = 0x150b7a02;\n\n    // Mapping from token ID to owner\n    mapping (uint256 => address) private _tokenOwner;\n\n    // Mapping from token ID to approved address\n    mapping (uint256 => address) private _tokenApprovals;\n\n    // Mapping from owner to number of owned token\n    mapping (address => Counters.Counter) private _ownedTokensCount;\n\n    // Mapping from owner to operator approvals\n    mapping (address => mapping (address => bool)) private _operatorApprovals;\n\n    /*\n     *     bytes4(keccak256('balanceOf(address)')) == 0x70a08231\n     *     bytes4(keccak256('ownerOf(uint256)')) == 0x6352211e\n     *     bytes4(keccak256('approve(address,uint256)')) == 0x095ea7b3\n     *     bytes4(keccak256('getApproved(uint256)')) == 0x081812fc\n     *     bytes4(keccak256('setApprovalForAll(address,bool)')) == 0xa22cb465\n     *     bytes4(keccak256('isApprovedForAll(address,address)')) == 0xe985e9c\n     *     bytes4(keccak256('transferFrom(address,address,uint256)')) == 0x23b872dd\n     *     bytes4(keccak256('safeTransferFrom(address,address,uint256)')) == 0x42842e0e\n     *     bytes4(keccak256('safeTransferFrom(address,address,uint256,bytes)')) == 0xb88d4fde\n     *\n     *     => 0x70a08231 ^ 0x6352211e ^ 0x095ea7b3 ^ 0x081812fc ^\n     *        0xa22cb465 ^ 0xe985e9c ^ 0x23b872dd ^ 0x42842e0e ^ 0xb88d4fde == 0x80ac58cd\n     */\n    bytes4 private constant _INTERFACE_ID_ERC721 = 0x80ac58cd;\n\n    constructor () public {\n        // register the supported interfaces to conform to ERC721 via ERC165\n        _registerInterface(_INTERFACE_ID_ERC721);\n    }\n\n    /**\n     * @dev Gets the balance of the specified address.\n     * @param owner address to query the balance of\n     * @return uint256 representing the amount owned by the passed address\n     */\n    function balanceOf(address owner) public view returns (uint256) {\n        require(owner != address(0), \"ERC721: balance query for the zero address\");\n\n        return _ownedTokensCount[owner].current();\n    }\n\n    /**\n     * @dev Gets the owner of the specified token ID.\n     * @param tokenId uint256 ID of the token to query the owner of\n     * @return address currently marked as the owner of the given token ID\n     */\n    function ownerOf(uint256 tokenId) public view returns (address) {\n        address owner = _tokenOwner[tokenId];\n        require(owner != address(0), \"ERC721: owner query for nonexistent token\");\n\n        return owner;\n    }\n\n    /**\n     * @dev Approves another address to transfer the given token ID\n     * The zero address indicates there is no approved address.\n     * There can only be one approved address per token at a given time.\n     * Can only be called by the token owner or an approved operator.\n     * @param to address to be approved for the given token ID\n     * @param tokenId uint256 ID of the token to be approved\n     */\n    function approve(address to, uint256 tokenId) public {\n        address owner = ownerOf(tokenId);\n        require(to != owner, \"ERC721: approval to current owner\");\n\n        require(msg.sender == owner || isApprovedForAll(owner, msg.sender),\n            \"ERC721: approve caller is not owner nor approved for all\"\n        );\n\n        _tokenApprovals[tokenId] = to;\n        emit Approval(owner, to, tokenId);\n    }\n\n    /**\n     * @dev Gets the approved address for a token ID, or zero if no address set\n     * Reverts if the token ID does not exist.\n     * @param tokenId uint256 ID of the token to query the approval of\n     * @return address currently approved for the given token ID\n     */\n    function getApproved(uint256 tokenId) public view returns (address) {\n        require(_exists(tokenId), \"ERC721: approved query for nonexistent token\");\n\n        return _tokenApprovals[tokenId];\n    }\n\n    /**\n     * @dev Sets or unsets the approval of a given operator\n     * An operator is allowed to transfer all tokens of the sender on their behalf.\n     * @param to operator address to set the approval\n     * @param approved representing the status of the approval to be set\n     */\n    function setApprovalForAll(address to, bool approved) public {\n        require(to != msg.sender, \"ERC721: approve to caller\");\n\n        _operatorApprovals[msg.sender][to] = approved;\n        emit ApprovalForAll(msg.sender, to, approved);\n    }\n\n    /**\n     * @dev Tells whether an operator is approved by a given owner.\n     * @param owner owner address which you want to query the approval of\n     * @param operator operator address which you want to query the approval of\n     * @return bool whether the given operator is approved by the given owner\n     */\n    function isApprovedForAll(address owner, address operator) public view returns (bool) {\n        return _operatorApprovals[owner][operator];\n    }\n\n    /**\n     * @dev Transfers the ownership of a given token ID to another address.\n     * Usage of this method is discouraged, use `safeTransferFrom` whenever possible.\n     * Requires the msg.sender to be the owner, approved, or operator.\n     * @param from current owner of the token\n     * @param to address to receive the ownership of the given token ID\n     * @param tokenId uint256 ID of the token to be transferred\n     */\n    function transferFrom(address from, address to, uint256 tokenId) public {\n        //solhint-disable-next-line max-line-length\n        require(_isApprovedOrOwner(msg.sender, tokenId), \"ERC721: transfer caller is not owner nor approved\");\n\n        _transferFrom(from, to, tokenId);\n    }\n\n    /**\n     * @dev Safely transfers the ownership of a given token ID to another address\n     * If the target address is a contract, it must implement `onERC721Received`,\n     * which is called upon a safe transfer, and return the magic value\n     * `bytes4(keccak256(\"onERC721Received(address,address,uint256,bytes)\"))`; otherwise,\n     * the transfer is reverted.\n     * Requires the msg.sender to be the owner, approved, or operator\n     * @param from current owner of the token\n     * @param to address to receive the ownership of the given token ID\n     * @param tokenId uint256 ID of the token to be transferred\n     */\n    function safeTransferFrom(address from, address to, uint256 tokenId) public {\n        safeTransferFrom(from, to, tokenId, \"\");\n    }\n\n    /**\n     * @dev Safely transfers the ownership of a given token ID to another address\n     * If the target address is a contract, it must implement `onERC721Received`,\n     * which is called upon a safe transfer, and return the magic value\n     * `bytes4(keccak256(\"onERC721Received(address,address,uint256,bytes)\"))`; otherwise,\n     * the transfer is reverted.\n     * Requires the msg.sender to be the owner, approved, or operator\n     * @param from current owner of the token\n     * @param to address to receive the ownership of the given token ID\n     * @param tokenId uint256 ID of the token to be transferred\n     * @param _data bytes data to send along with a safe transfer check\n     */\n    function safeTransferFrom(address from, address to, uint256 tokenId, bytes memory _data) public {\n        transferFrom(from, to, tokenId);\n        require(_checkOnERC721Received(from, to, tokenId, _data), \"ERC721: transfer to non ERC721Receiver implementer\");\n    }\n\n    /**\n     * @dev Returns whether the specified token exists.\n     * @param tokenId uint256 ID of the token to query the existence of\n     * @return bool whether the token exists\n     */\n    function _exists(uint256 tokenId) internal view returns (bool) {\n        address owner = _tokenOwner[tokenId];\n        return owner != address(0);\n    }\n\n    /**\n     * @dev Returns whether the given spender can transfer a given token ID.\n     * @param spender address of the spender to query\n     * @param tokenId uint256 ID of the token to be transferred\n     * @return bool whether the msg.sender is approved for the given token ID,\n     * is an operator of the owner, or is the owner of the token\n     */\n    function _isApprovedOrOwner(address spender, uint256 tokenId) internal view returns (bool) {\n        require(_exists(tokenId), \"ERC721: operator query for nonexistent token\");\n        address owner = ownerOf(tokenId);\n        return (spender == owner || getApproved(tokenId) == spender || isApprovedForAll(owner, spender));\n    }\n\n    /**\n     * @dev Internal function to mint a new token.\n     * Reverts if the given token ID already exists.\n     * @param to The address that will own the minted token\n     * @param tokenId uint256 ID of the token to be minted\n     */\n    function _mint(address to, uint256 tokenId) internal {\n        require(to != address(0), \"ERC721: mint to the zero address\");\n        require(!_exists(tokenId), \"ERC721: token already minted\");\n\n        _tokenOwner[tokenId] = to;\n        _ownedTokensCount[to].increment();\n\n        emit Transfer(address(0), to, tokenId);\n    }\n\n    /**\n     * @dev Internal function to burn a specific token.\n     * Reverts if the token does not exist.\n     * Deprecated, use _burn(uint256) instead.\n     * @param owner owner of the token to burn\n     * @param tokenId uint256 ID of the token being burned\n     */\n    function _burn(address owner, uint256 tokenId) internal {\n        require(ownerOf(tokenId) == owner, \"ERC721: burn of token that is not own\");\n\n        _clearApproval(tokenId);\n\n        _ownedTokensCount[owner].decrement();\n        _tokenOwner[tokenId] = address(0);\n\n        emit Transfer(owner, address(0), tokenId);\n    }\n\n    /**\n     * @dev Internal function to burn a specific token.\n     * Reverts if the token does not exist.\n     * @param tokenId uint256 ID of the token being burned\n     */\n    function _burn(uint256 tokenId) internal {\n        _burn(ownerOf(tokenId), tokenId);\n    }\n\n    /**\n     * @dev Internal function to transfer ownership of a given token ID to another address.\n     * As opposed to transferFrom, this imposes no restrictions on msg.sender.\n     * @param from current owner of the token\n     * @param to address to receive the ownership of the given token ID\n     * @param tokenId uint256 ID of the token to be transferred\n     */\n    function _transferFrom(address from, address to, uint256 tokenId) internal {\n        require(ownerOf(tokenId) == from, \"ERC721: transfer of token that is not own\");\n        require(to != address(0), \"ERC721: transfer to the zero address\");\n\n        _clearApproval(tokenId);\n\n        _ownedTokensCount[from].decrement();\n        _ownedTokensCount[to].increment();\n\n        _tokenOwner[tokenId] = to;\n\n        emit Transfer(from, to, tokenId);\n    }\n\n    /**\n     * @dev Internal function to invoke `onERC721Received` on a target address.\n     * The call is not executed if the target address is not a contract.\n     *\n     * This function is deprecated.\n     * @param from address representing the previous owner of the given token ID\n     * @param to target address that will receive the tokens\n     * @param tokenId uint256 ID of the token to be transferred\n     * @param _data bytes optional data to send along with the call\n     * @return bool whether the call correctly returned the expected magic value\n     */\n    function _checkOnERC721Received(address from, address to, uint256 tokenId, bytes memory _data)\n        internal returns (bool)\n    {\n        if (!to.isContract()) {\n            return true;\n        }\n\n        bytes4 retval = IERC721Receiver(to).onERC721Received(msg.sender, from, tokenId, _data);\n        return (retval == _ERC721_RECEIVED);\n    }\n\n    /**\n     * @dev Private function to clear current approval of a given token ID.\n     * @param tokenId uint256 ID of the token to be transferred\n     */\n    function _clearApproval(uint256 tokenId) private {\n        if (_tokenApprovals[tokenId] != address(0)) {\n            _tokenApprovals[tokenId] = address(0);\n        }\n    }\n}\n\n// File: @openzeppelin/contracts/token/ERC721/IERC721Enumerable.sol\n\npragma solidity ^0.5.0;\n\n\n/**\n * @title ERC-721 Non-Fungible Token Standard, optional enumeration extension\n * @dev See https://eips.ethereum.org/EIPS/eip-721\n */\ncontract IERC721Enumerable is IERC721 {\n    function totalSupply() public view returns (uint256);\n    function tokenOfOwnerByIndex(address owner, uint256 index) public view returns (uint256 tokenId);\n\n    function tokenByIndex(uint256 index) public view returns (uint256);\n}\n\n// File: @openzeppelin/contracts/token/ERC721/ERC721Enumerable.sol\n\npragma solidity ^0.5.0;\n\n\n\n\n/**\n * @title ERC-721 Non-Fungible Token with optional enumeration extension logic\n * @dev See https://eips.ethereum.org/EIPS/eip-721\n */\ncontract ERC721Enumerable is ERC165, ERC721, IERC721Enumerable {\n    // Mapping from owner to list of owned token IDs\n    mapping(address => uint256[]) private _ownedTokens;\n\n    // Mapping from token ID to index of the owner tokens list\n    mapping(uint256 => uint256) private _ownedTokensIndex;\n\n    // Array with all token ids, used for enumeration\n    uint256[] private _allTokens;\n\n    // Mapping from token id to position in the allTokens array\n    mapping(uint256 => uint256) private _allTokensIndex;\n\n    /*\n     *     bytes4(keccak256('totalSupply()')) == 0x18160ddd\n     *     bytes4(keccak256('tokenOfOwnerByIndex(address,uint256)')) == 0x2f745c59\n     *     bytes4(keccak256('tokenByIndex(uint256)')) == 0x4f6ccce7\n     *\n     *     => 0x18160ddd ^ 0x2f745c59 ^ 0x4f6ccce7 == 0x780e9d63\n     */\n    bytes4 private constant _INTERFACE_ID_ERC721_ENUMERABLE = 0x780e9d63;\n\n    /**\n     * @dev Constructor function.\n     */\n    constructor () public {\n        // register the supported interface to conform to ERC721Enumerable via ERC165\n        _registerInterface(_INTERFACE_ID_ERC721_ENUMERABLE);\n    }\n\n    /**\n     * @dev Gets the token ID at a given index of the tokens list of the requested owner.\n     * @param owner address owning the tokens list to be accessed\n     * @param index uint256 representing the index to be accessed of the requested tokens list\n     * @return uint256 token ID at the given index of the tokens list owned by the requested address\n     */\n    function tokenOfOwnerByIndex(address owner, uint256 index) public view returns (uint256) {\n        require(index < balanceOf(owner), \"ERC721Enumerable: owner index out of bounds\");\n        return _ownedTokens[owner][index];\n    }\n\n    /**\n     * @dev Gets the total amount of tokens stored by the contract.\n     * @return uint256 representing the total amount of tokens\n     */\n    function totalSupply() public view returns (uint256) {\n        return _allTokens.length;\n    }\n\n    /**\n     * @dev Gets the token ID at a given index of all the tokens in this contract\n     * Reverts if the index is greater or equal to the total number of tokens.\n     * @param index uint256 representing the index to be accessed of the tokens list\n     * @return uint256 token ID at the given index of the tokens list\n     */\n    function tokenByIndex(uint256 index) public view returns (uint256) {\n        require(index < totalSupply(), \"ERC721Enumerable: global index out of bounds\");\n        return _allTokens[index];\n    }\n\n    /**\n     * @dev Internal function to transfer ownership of a given token ID to another address.\n     * As opposed to transferFrom, this imposes no restrictions on msg.sender.\n     * @param from current owner of the token\n     * @param to address to receive the ownership of the given token ID\n     * @param tokenId uint256 ID of the token to be transferred\n     */\n    function _transferFrom(address from, address to, uint256 tokenId) internal {\n        super._transferFrom(from, to, tokenId);\n\n        _removeTokenFromOwnerEnumeration(from, tokenId);\n\n        _addTokenToOwnerEnumeration(to, tokenId);\n    }\n\n    /**\n     * @dev Internal function to mint a new token.\n     * Reverts if the given token ID already exists.\n     * @param to address the beneficiary that will own the minted token\n     * @param tokenId uint256 ID of the token to be minted\n     */\n    function _mint(address to, uint256 tokenId) internal {\n        super._mint(to, tokenId);\n\n        _addTokenToOwnerEnumeration(to, tokenId);\n\n        _addTokenToAllTokensEnumeration(tokenId);\n    }\n\n    /**\n     * @dev Internal function to burn a specific token.\n     * Reverts if the token does not exist.\n     * Deprecated, use _burn(uint256) instead.\n     * @param owner owner of the token to burn\n     * @param tokenId uint256 ID of the token being burned\n     */\n    function _burn(address owner, uint256 tokenId) internal {\n        super._burn(owner, tokenId);\n\n        _removeTokenFromOwnerEnumeration(owner, tokenId);\n        // Since tokenId will be deleted, we can clear its slot in _ownedTokensIndex to trigger a gas refund\n        _ownedTokensIndex[tokenId] = 0;\n\n        _removeTokenFromAllTokensEnumeration(tokenId);\n    }\n\n    /**\n     * @dev Gets the list of token IDs of the requested owner.\n     * @param owner address owning the tokens\n     * @return uint256[] List of token IDs owned by the requested address\n     */\n    function _tokensOfOwner(address owner) internal view returns (uint256[] storage) {\n        return _ownedTokens[owner];\n    }\n\n    /**\n     * @dev Private function to add a token to this extension's ownership-tracking data structures.\n     * @param to address representing the new owner of the given token ID\n     * @param tokenId uint256 ID of the token to be added to the tokens list of the given address\n     */\n    function _addTokenToOwnerEnumeration(address to, uint256 tokenId) private {\n        _ownedTokensIndex[tokenId] = _ownedTokens[to].length;\n        _ownedTokens[to].push(tokenId);\n    }\n\n    /**\n     * @dev Private function to add a token to this extension's token tracking data structures.\n     * @param tokenId uint256 ID of the token to be added to the tokens list\n     */\n    function _addTokenToAllTokensEnumeration(uint256 tokenId) private {\n        _allTokensIndex[tokenId] = _allTokens.length;\n        _allTokens.push(tokenId);\n    }\n\n    /**\n     * @dev Private function to remove a token from this extension's ownership-tracking data structures. Note that\n     * while the token is not assigned a new owner, the _ownedTokensIndex mapping is _not_ updated: this allows for\n     * gas optimizations e.g. when performing a transfer operation (avoiding double writes).\n     * This has O(1) time complexity, but alters the order of the _ownedTokens array.\n     * @param from address representing the previous owner of the given token ID\n     * @param tokenId uint256 ID of the token to be removed from the tokens list of the given address\n     */\n    function _removeTokenFromOwnerEnumeration(address from, uint256 tokenId) private {\n        // To prevent a gap in from's tokens array, we store the last token in the index of the token to delete, and\n        // then delete the last slot (swap and pop).\n\n        uint256 lastTokenIndex = _ownedTokens[from].length.sub(1);\n        uint256 tokenIndex = _ownedTokensIndex[tokenId];\n\n        // When the token to delete is the last token, the swap operation is unnecessary\n        if (tokenIndex != lastTokenIndex) {\n            uint256 lastTokenId = _ownedTokens[from][lastTokenIndex];\n\n            _ownedTokens[from][tokenIndex] = lastTokenId; // Move the last token to the slot of the to-delete token\n            _ownedTokensIndex[lastTokenId] = tokenIndex; // Update the moved token's index\n        }\n\n        // This also deletes the contents at the last position of the array\n        _ownedTokens[from].length--;\n\n        // Note that _ownedTokensIndex[tokenId] hasn't been cleared: it still points to the old slot (now occupied by\n        // lastTokenId, or just over the end of the array if the token was the last one).\n    }\n\n    /**\n     * @dev Private function to remove a token from this extension's token tracking data structures.\n     * This has O(1) time complexity, but alters the order of the _allTokens array.\n     * @param tokenId uint256 ID of the token to be removed from the tokens list\n     */\n    function _removeTokenFromAllTokensEnumeration(uint256 tokenId) private {\n        // To prevent a gap in the tokens array, we store the last token in the index of the token to delete, and\n        // then delete the last slot (swap and pop).\n\n        uint256 lastTokenIndex = _allTokens.length.sub(1);\n        uint256 tokenIndex = _allTokensIndex[tokenId];\n\n        // When the token to delete is the last token, the swap operation is unnecessary. 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May return an empty string.\n     * @param tokenId uint256 ID of the token to query\n     */\n    function tokenURI(uint256 tokenId) external view returns (string memory) {\n        require(_exists(tokenId), \"ERC721Metadata: URI query for nonexistent token\");\n        return _tokenURIs[tokenId];\n    }\n\n    /**\n     * @dev Internal function to set the token URI for a given token.\n     * Reverts if the token ID does not exist.\n     * @param tokenId uint256 ID of the token to set its URI\n     * @param uri string URI to assign\n     */\n    function _setTokenURI(uint256 tokenId, string memory uri) internal {\n        require(_exists(tokenId), \"ERC721Metadata: URI set of nonexistent token\");\n        _tokenURIs[tokenId] = uri;\n    }\n\n    /**\n     * @dev Internal function to burn a specific token.\n     * Reverts if the token does not exist.\n     * Deprecated, use _burn(uint256) instead.\n     * @param owner owner of the token to burn\n     * @param tokenId uint256 ID of the token being burned by the msg.sender\n     */\n    function _burn(address owner, uint256 tokenId) internal {\n        super._burn(owner, tokenId);\n\n        // Clear metadata (if any)\n        if (bytes(_tokenURIs[tokenId]).length != 0) {\n            delete _tokenURIs[tokenId];\n        }\n    }\n}\n\n// File: @openzeppelin/contracts/token/ERC721/ERC721Full.sol\n\npragma solidity ^0.5.0;\n\n\n\n\n/**\n * @title Full ERC721 Token\n * This implementation includes all the required and some optional functionality of the ERC721 standard\n * Moreover, it includes approve all functionality using operator terminology\n * @dev see https://eips.ethereum.org/EIPS/eip-721\n */\ncontract ERC721Full is ERC721, ERC721Enumerable, ERC721Metadata {\n    constructor (string memory name, string memory symbol) public ERC721Metadata(name, symbol) {\n        // solhint-disable-previous-line no-empty-blocks\n    }\n}\n",
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+                          "typeIdentifier": "t_address_payable",
+                          "typeString": "address payable"
+                        },
+                        {
+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        },
+                        {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      ],
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+                      "name": "Transfer",
+                      "nodeType": "Identifier",
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+                      "src": "21063:8:1",
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+                    "isConstant": false,
+                    "isLValue": false,
+                    "isPure": false,
+                    "kind": "functionCall",
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+                    "names": [],
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+                    "src": "21063:33:1",
+                    "typeDescriptions": {
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+                      "typeString": "tuple()"
+                    }
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+                  "id": 766,
+                  "nodeType": "EmitStatement",
+                  "src": "21058:38:1"
+                }
+              ]
+            },
+            "documentation": "@dev Internal function to mint a new token.\nReverts if the given token ID already exists.\n@param to The address that will own the minted token\n@param tokenId uint256 ID of the token to be minted",
+            "id": 768,
+            "implemented": true,
+            "kind": "function",
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+            "name": "_mint",
+            "nodeType": "FunctionDefinition",
+            "parameters": {
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+              "nodeType": "ParameterList",
+              "parameters": [
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+                  "id": 725,
+                  "name": "to",
+                  "nodeType": "VariableDeclaration",
+                  "scope": 768,
+                  "src": "20791:10:1",
+                  "stateVariable": false,
+                  "storageLocation": "default",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_address",
+                    "typeString": "address"
+                  },
+                  "typeName": {
+                    "id": 724,
+                    "name": "address",
+                    "nodeType": "ElementaryTypeName",
+                    "src": "20791:7:1",
+                    "stateMutability": "nonpayable",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_address",
+                      "typeString": "address"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                },
+                {
+                  "constant": false,
+                  "id": 727,
+                  "name": "tokenId",
+                  "nodeType": "VariableDeclaration",
+                  "scope": 768,
+                  "src": "20803:15:1",
+                  "stateVariable": false,
+                  "storageLocation": "default",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_uint256",
+                    "typeString": "uint256"
+                  },
+                  "typeName": {
+                    "id": 726,
+                    "name": "uint256",
+                    "nodeType": "ElementaryTypeName",
+                    "src": "20803:7:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_uint256",
+                      "typeString": "uint256"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                }
+              ],
+              "src": "20790:29:1"
+            },
+            "returnParameters": {
+              "id": 729,
+              "nodeType": "ParameterList",
+              "parameters": [],
+              "src": "20829:0:1"
+            },
+            "scope": 944,
+            "src": "20776:327:1",
+            "stateMutability": "nonpayable",
+            "superFunction": null,
+            "visibility": "internal"
+          },
+          {
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+              "id": 810,
+              "nodeType": "Block",
+              "src": "21434:268:1",
+              "statements": [
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+                    "argumentTypes": null,
+                    "arguments": [
+                      {
+                        "argumentTypes": null,
+                        "commonType": {
+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        },
+                        "id": 780,
+                        "isConstant": false,
+                        "isLValue": false,
+                        "isPure": false,
+                        "lValueRequested": false,
+                        "leftExpression": {
+                          "argumentTypes": null,
+                          "arguments": [
+                            {
+                              "argumentTypes": null,
+                              "id": 777,
+                              "name": "tokenId",
+                              "nodeType": "Identifier",
+                              "overloadedDeclarations": [],
+                              "referencedDeclaration": 772,
+                              "src": "21460:7:1",
+                              "typeDescriptions": {
+                                "typeIdentifier": "t_uint256",
+                                "typeString": "uint256"
+                              }
+                            }
+                          ],
+                          "expression": {
+                            "argumentTypes": [
+                              {
+                                "typeIdentifier": "t_uint256",
+                                "typeString": "uint256"
+                              }
+                            ],
+                            "id": 776,
+                            "name": "ownerOf",
+                            "nodeType": "Identifier",
+                            "overloadedDeclarations": [
+                              480
+                            ],
+                            "referencedDeclaration": 480,
+                            "src": "21452:7:1",
+                            "typeDescriptions": {
+                              "typeIdentifier": "t_function_internal_view$_t_uint256_$returns$_t_address_$",
+                              "typeString": "function (uint256) view returns (address)"
+                            }
+                          },
+                          "id": 778,
+                          "isConstant": false,
+                          "isLValue": false,
+                          "isPure": false,
+                          "kind": "functionCall",
+                          "lValueRequested": false,
+                          "names": [],
+                          "nodeType": "FunctionCall",
+                          "src": "21452:16:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_address",
+                            "typeString": "address"
+                          }
+                        },
+                        "nodeType": "BinaryOperation",
+                        "operator": "==",
+                        "rightExpression": {
+                          "argumentTypes": null,
+                          "id": 779,
+                          "name": "owner",
+                          "nodeType": "Identifier",
+                          "overloadedDeclarations": [],
+                          "referencedDeclaration": 770,
+                          "src": "21472:5:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_address",
+                            "typeString": "address"
+                          }
+                        },
+                        "src": "21452:25:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_bool",
+                          "typeString": "bool"
+                        }
+                      },
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+                        "argumentTypes": null,
+                        "hexValue": "4552433732313a206275726e206f6620746f6b656e2074686174206973206e6f74206f776e",
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+                        "isConstant": false,
+                        "isLValue": false,
+                        "isPure": true,
+                        "kind": "string",
+                        "lValueRequested": false,
+                        "nodeType": "Literal",
+                        "src": "21479:39:1",
+                        "subdenomination": null,
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_stringliteral_d9af5b321f427d3820b5fc07b432b1ddf1bb6411d5d926d9de9773fd616ab5ee",
+                          "typeString": "literal_string \"ERC721: burn of token that is not own\""
+                        },
+                        "value": "ERC721: burn of token that is not own"
+                      }
+                    ],
+                    "expression": {
+                      "argumentTypes": [
+                        {
+                          "typeIdentifier": "t_bool",
+                          "typeString": "bool"
+                        },
+                        {
+                          "typeIdentifier": "t_stringliteral_d9af5b321f427d3820b5fc07b432b1ddf1bb6411d5d926d9de9773fd616ab5ee",
+                          "typeString": "literal_string \"ERC721: burn of token that is not own\""
+                        }
+                      ],
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+                      "name": "require",
+                      "nodeType": "Identifier",
+                      "overloadedDeclarations": [
+                        1543,
+                        1544
+                      ],
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+                      "src": "21444:7:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_function_require_pure$_t_bool_$_t_string_memory_ptr_$returns$__$",
+                        "typeString": "function (bool,string memory) pure"
+                      }
+                    },
+                    "id": 782,
+                    "isConstant": false,
+                    "isLValue": false,
+                    "isPure": false,
+                    "kind": "functionCall",
+                    "lValueRequested": false,
+                    "names": [],
+                    "nodeType": "FunctionCall",
+                    "src": "21444:75:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_tuple$__$",
+                      "typeString": "tuple()"
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+                  },
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+                  "nodeType": "ExpressionStatement",
+                  "src": "21444:75:1"
+                },
+                {
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+                    "arguments": [
+                      {
+                        "argumentTypes": null,
+                        "id": 785,
+                        "name": "tokenId",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 772,
+                        "src": "21545:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      }
+                    ],
+                    "expression": {
+                      "argumentTypes": [
+                        {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      ],
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+                      "name": "_clearApproval",
+                      "nodeType": "Identifier",
+                      "overloadedDeclarations": [],
+                      "referencedDeclaration": 943,
+                      "src": "21530:14:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_function_internal_nonpayable$_t_uint256_$returns$__$",
+                        "typeString": "function (uint256)"
+                      }
+                    },
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+                    "isConstant": false,
+                    "isLValue": false,
+                    "isPure": false,
+                    "kind": "functionCall",
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+                      "typeString": "tuple()"
+                    }
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+                  "nodeType": "ExpressionStatement",
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+                },
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+                        "baseExpression": {
+                          "argumentTypes": null,
+                          "id": 788,
+                          "name": "_ownedTokensCount",
+                          "nodeType": "Identifier",
+                          "overloadedDeclarations": [],
+                          "referencedDeclaration": 415,
+                          "src": "21564:17:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_mapping$_t_address_$_t_struct$_Counter_$296_storage_$",
+                            "typeString": "mapping(address => struct Counters.Counter storage ref)"
+                          }
+                        },
+                        "id": 790,
+                        "indexExpression": {
+                          "argumentTypes": null,
+                          "id": 789,
+                          "name": "owner",
+                          "nodeType": "Identifier",
+                          "overloadedDeclarations": [],
+                          "referencedDeclaration": 770,
+                          "src": "21582:5:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_address",
+                            "typeString": "address"
+                          }
+                        },
+                        "isConstant": false,
+                        "isLValue": true,
+                        "isPure": false,
+                        "lValueRequested": false,
+                        "nodeType": "IndexAccess",
+                        "src": "21564:24:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_struct$_Counter_$296_storage",
+                          "typeString": "struct Counters.Counter storage ref"
+                        }
+                      },
+                      "id": 791,
+                      "isConstant": false,
+                      "isLValue": true,
+                      "isPure": false,
+                      "lValueRequested": false,
+                      "memberName": "decrement",
+                      "nodeType": "MemberAccess",
+                      "referencedDeclaration": 335,
+                      "src": "21564:34:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_function_internal_nonpayable$_t_struct$_Counter_$296_storage_ptr_$returns$__$bound_to$_t_struct$_Counter_$296_storage_ptr_$",
+                        "typeString": "function (struct Counters.Counter storage pointer)"
+                      }
+                    },
+                    "id": 792,
+                    "isConstant": false,
+                    "isLValue": false,
+                    "isPure": false,
+                    "kind": "functionCall",
+                    "lValueRequested": false,
+                    "names": [],
+                    "nodeType": "FunctionCall",
+                    "src": "21564:36:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_tuple$__$",
+                      "typeString": "tuple()"
+                    }
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+                  "id": 793,
+                  "nodeType": "ExpressionStatement",
+                  "src": "21564:36:1"
+                },
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+                    "id": 800,
+                    "isConstant": false,
+                    "isLValue": false,
+                    "isPure": false,
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+                    "leftHandSide": {
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+                      "baseExpression": {
+                        "argumentTypes": null,
+                        "id": 794,
+                        "name": "_tokenOwner",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 407,
+                        "src": "21610:11:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_mapping$_t_uint256_$_t_address_$",
+                          "typeString": "mapping(uint256 => address)"
+                        }
+                      },
+                      "id": 796,
+                      "indexExpression": {
+                        "argumentTypes": null,
+                        "id": 795,
+                        "name": "tokenId",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 772,
+                        "src": "21622:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      },
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+                      "isLValue": true,
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+                      "nodeType": "IndexAccess",
+                      "src": "21610:20:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_address",
+                        "typeString": "address"
+                      }
+                    },
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+                    "operator": "=",
+                    "rightHandSide": {
+                      "argumentTypes": null,
+                      "arguments": [
+                        {
+                          "argumentTypes": null,
+                          "hexValue": "30",
+                          "id": 798,
+                          "isConstant": false,
+                          "isLValue": false,
+                          "isPure": true,
+                          "kind": "number",
+                          "lValueRequested": false,
+                          "nodeType": "Literal",
+                          "src": "21641:1:1",
+                          "subdenomination": null,
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_rational_0_by_1",
+                            "typeString": "int_const 0"
+                          },
+                          "value": "0"
+                        }
+                      ],
+                      "expression": {
+                        "argumentTypes": [
+                          {
+                            "typeIdentifier": "t_rational_0_by_1",
+                            "typeString": "int_const 0"
+                          }
+                        ],
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+                        "isConstant": false,
+                        "isLValue": false,
+                        "isPure": true,
+                        "lValueRequested": false,
+                        "nodeType": "ElementaryTypeNameExpression",
+                        "src": "21633:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_type$_t_address_$",
+                          "typeString": "type(address)"
+                        },
+                        "typeName": "address"
+                      },
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+                      "isConstant": false,
+                      "isLValue": false,
+                      "isPure": true,
+                      "kind": "typeConversion",
+                      "lValueRequested": false,
+                      "names": [],
+                      "nodeType": "FunctionCall",
+                      "src": "21633:10:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_address_payable",
+                        "typeString": "address payable"
+                      }
+                    },
+                    "src": "21610:33:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_address",
+                      "typeString": "address"
+                    }
+                  },
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+                  "nodeType": "ExpressionStatement",
+                  "src": "21610:33:1"
+                },
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+                    "arguments": [
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+                        "argumentTypes": null,
+                        "id": 803,
+                        "name": "owner",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 770,
+                        "src": "21668:5:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        }
+                      },
+                      {
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+                        "arguments": [
+                          {
+                            "argumentTypes": null,
+                            "hexValue": "30",
+                            "id": 805,
+                            "isConstant": false,
+                            "isLValue": false,
+                            "isPure": true,
+                            "kind": "number",
+                            "lValueRequested": false,
+                            "nodeType": "Literal",
+                            "src": "21683:1:1",
+                            "subdenomination": null,
+                            "typeDescriptions": {
+                              "typeIdentifier": "t_rational_0_by_1",
+                              "typeString": "int_const 0"
+                            },
+                            "value": "0"
+                          }
+                        ],
+                        "expression": {
+                          "argumentTypes": [
+                            {
+                              "typeIdentifier": "t_rational_0_by_1",
+                              "typeString": "int_const 0"
+                            }
+                          ],
+                          "id": 804,
+                          "isConstant": false,
+                          "isLValue": false,
+                          "isPure": true,
+                          "lValueRequested": false,
+                          "nodeType": "ElementaryTypeNameExpression",
+                          "src": "21675:7:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_type$_t_address_$",
+                            "typeString": "type(address)"
+                          },
+                          "typeName": "address"
+                        },
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+                        "isConstant": false,
+                        "isLValue": false,
+                        "isPure": true,
+                        "kind": "typeConversion",
+                        "lValueRequested": false,
+                        "names": [],
+                        "nodeType": "FunctionCall",
+                        "src": "21675:10:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_address_payable",
+                          "typeString": "address payable"
+                        }
+                      },
+                      {
+                        "argumentTypes": null,
+                        "id": 807,
+                        "name": "tokenId",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 772,
+                        "src": "21687:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      }
+                    ],
+                    "expression": {
+                      "argumentTypes": [
+                        {
+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        },
+                        {
+                          "typeIdentifier": "t_address_payable",
+                          "typeString": "address payable"
+                        },
+                        {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      ],
+                      "id": 802,
+                      "name": "Transfer",
+                      "nodeType": "Identifier",
+                      "overloadedDeclarations": [],
+                      "referencedDeclaration": 34,
+                      "src": "21659:8:1",
+                      "typeDescriptions": {
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+                        "typeString": "function (address,address,uint256)"
+                      }
+                    },
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+                    "isLValue": false,
+                    "isPure": false,
+                    "kind": "functionCall",
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+                    "nodeType": "FunctionCall",
+                    "src": "21659:36:1",
+                    "typeDescriptions": {
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+                      "typeString": "tuple()"
+                    }
+                  },
+                  "id": 809,
+                  "nodeType": "EmitStatement",
+                  "src": "21654:41:1"
+                }
+              ]
+            },
+            "documentation": "@dev Internal function to burn a specific token.\nReverts if the token does not exist.\nDeprecated, use _burn(uint256) instead.\n@param owner owner of the token to burn\n@param tokenId uint256 ID of the token being burned",
+            "id": 811,
+            "implemented": true,
+            "kind": "function",
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+              "nodeType": "ParameterList",
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+                  "id": 770,
+                  "name": "owner",
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+                  "scope": 811,
+                  "src": "21393:13:1",
+                  "stateVariable": false,
+                  "storageLocation": "default",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_address",
+                    "typeString": "address"
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+                  "typeName": {
+                    "id": 769,
+                    "name": "address",
+                    "nodeType": "ElementaryTypeName",
+                    "src": "21393:7:1",
+                    "stateMutability": "nonpayable",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_address",
+                      "typeString": "address"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                },
+                {
+                  "constant": false,
+                  "id": 772,
+                  "name": "tokenId",
+                  "nodeType": "VariableDeclaration",
+                  "scope": 811,
+                  "src": "21408:15:1",
+                  "stateVariable": false,
+                  "storageLocation": "default",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_uint256",
+                    "typeString": "uint256"
+                  },
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+                    "name": "uint256",
+                    "nodeType": "ElementaryTypeName",
+                    "src": "21408:7:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_uint256",
+                      "typeString": "uint256"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                }
+              ],
+              "src": "21392:32:1"
+            },
+            "returnParameters": {
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+              "nodeType": "ParameterList",
+              "parameters": [],
+              "src": "21434:0:1"
+            },
+            "scope": 944,
+            "src": "21378:324:1",
+            "stateMutability": "nonpayable",
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+            "visibility": "internal"
+          },
+          {
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+              "nodeType": "Block",
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+              "statements": [
+                {
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+                    "argumentTypes": null,
+                    "arguments": [
+                      {
+                        "argumentTypes": null,
+                        "arguments": [
+                          {
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+                          "typeString": "address"
+                        }
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+                        "typeDescriptions": {
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+                          "typeString": "address"
+                        }
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+                        "id": 876,
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+                        "src": "22780:7:1",
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+                          "typeString": "uint256"
+                        }
+                      }
+                    ],
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+                      "argumentTypes": [
+                        {
+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        },
+                        {
+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        },
+                        {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      ],
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+                      "name": "Transfer",
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+                }
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+            },
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+                      "typeString": "address"
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+                          "src": "23514:2:1",
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+                            "typeIdentifier": "t_address",
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+                          "typeIdentifier": "t_bytes4",
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+                          "name": "msg",
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+                          "src": "23630:3:1",
+                          "typeDescriptions": {
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+                            "typeString": "msg"
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+                        "src": "23630:10:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_address_payable",
+                          "typeString": "address payable"
+                        }
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+                        "name": "from",
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+                        "typeDescriptions": {
+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        }
+                      },
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+                        "name": "tokenId",
+                        "nodeType": "Identifier",
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+                        "src": "23648:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
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+                        "name": "_data",
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+                        "src": "23657:5:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_bytes_memory_ptr",
+                          "typeString": "bytes memory"
+                        }
+                      }
+                    ],
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+                      "argumentTypes": [
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+                          "typeIdentifier": "t_address_payable",
+                          "typeString": "address payable"
+                        },
+                        {
+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        },
+                        {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        },
+                        {
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+                          "typeString": "bytes memory"
+                        }
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+                            "src": "23609:2:1",
+                            "typeDescriptions": {
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+                              "typeString": "address"
+                            }
+                          }
+                        ],
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+                              "typeIdentifier": "t_address",
+                              "typeString": "address"
+                            }
+                          ],
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+                          "name": "IERC721Receiver",
+                          "nodeType": "Identifier",
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+                          "referencedDeclaration": 139,
+                          "src": "23593:15:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_type$_t_contract$_IERC721Receiver_$139_$",
+                            "typeString": "type(contract IERC721Receiver)"
+                          }
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+                        "kind": "typeConversion",
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+                          "typeIdentifier": "t_contract$_IERC721Receiver_$139",
+                          "typeString": "contract IERC721Receiver"
+                        }
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+                      }
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+                    }
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+                  "src": "23577:86:1"
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+                        "commonType": {
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+                          "typeString": "bytes4"
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+                          "src": "23681:6:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_bytes4",
+                            "typeString": "bytes4"
+                          }
+                        },
+                        "nodeType": "BinaryOperation",
+                        "operator": "==",
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+                          "argumentTypes": null,
+                          "id": 915,
+                          "name": "_ERC721_RECEIVED",
+                          "nodeType": "Identifier",
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+                          "referencedDeclaration": 403,
+                          "src": "23691:16:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_bytes4",
+                            "typeString": "bytes4"
+                          }
+                        },
+                        "src": "23681:26:1",
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+                          "typeString": "bool"
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+                  "nodeType": "Return",
+                  "src": "23673:35:1"
+                }
+              ]
+            },
+            "documentation": "@dev Internal function to invoke `onERC721Received` on a target address.\nThe call is not executed if the target address is not a contract.\n     * This function is deprecated.\n@param from address representing the previous owner of the given token ID\n@param to target address that will receive the tokens\n@param tokenId uint256 ID of the token to be transferred\n@param _data bytes optional data to send along with the call\n@return bool whether the call correctly returned the expected magic value",
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+            "kind": "function",
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+                  "storageLocation": "default",
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+                  "src": "23414:10:1",
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+                    "typeString": "address"
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+                  "src": "23443:18:1",
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+                  "storageLocation": "memory",
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+                      "typeDescriptions": {
+                        "typeIdentifier": "t_function_require_pure$_t_bool_$_t_string_memory_ptr_$returns$__$",
+                        "typeString": "function (bool,string memory) pure"
+                      }
+                    },
+                    "id": 1050,
+                    "isConstant": false,
+                    "isLValue": false,
+                    "isPure": false,
+                    "kind": "functionCall",
+                    "lValueRequested": false,
+                    "names": [],
+                    "nodeType": "FunctionCall",
+                    "src": "27171:78:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_tuple$__$",
+                      "typeString": "tuple()"
+                    }
+                  },
+                  "id": 1051,
+                  "nodeType": "ExpressionStatement",
+                  "src": "27171:78:1"
+                },
+                {
+                  "expression": {
+                    "argumentTypes": null,
+                    "baseExpression": {
+                      "argumentTypes": null,
+                      "id": 1052,
+                      "name": "_allTokens",
+                      "nodeType": "Identifier",
+                      "overloadedDeclarations": [],
+                      "referencedDeclaration": 988,
+                      "src": "27266:10:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_array$_t_uint256_$dyn_storage",
+                        "typeString": "uint256[] storage ref"
+                      }
+                    },
+                    "id": 1054,
+                    "indexExpression": {
+                      "argumentTypes": null,
+                      "id": 1053,
+                      "name": "index",
+                      "nodeType": "Identifier",
+                      "overloadedDeclarations": [],
+                      "referencedDeclaration": 1039,
+                      "src": "27277:5:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_uint256",
+                        "typeString": "uint256"
+                      }
+                    },
+                    "isConstant": false,
+                    "isLValue": true,
+                    "isPure": false,
+                    "lValueRequested": false,
+                    "nodeType": "IndexAccess",
+                    "src": "27266:17:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_uint256",
+                      "typeString": "uint256"
+                    }
+                  },
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+                  "id": 1055,
+                  "nodeType": "Return",
+                  "src": "27259:24:1"
+                }
+              ]
+            },
+            "documentation": "@dev Gets the token ID at a given index of all the tokens in this contract\nReverts if the index is greater or equal to the total number of tokens.\n@param index uint256 representing the index to be accessed of the tokens list\n@return uint256 token ID at the given index of the tokens list",
+            "id": 1057,
+            "implemented": true,
+            "kind": "function",
+            "modifiers": [],
+            "name": "tokenByIndex",
+            "nodeType": "FunctionDefinition",
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+              "id": 1040,
+              "nodeType": "ParameterList",
+              "parameters": [
+                {
+                  "constant": false,
+                  "id": 1039,
+                  "name": "index",
+                  "nodeType": "VariableDeclaration",
+                  "scope": 1057,
+                  "src": "27116:13:1",
+                  "stateVariable": false,
+                  "storageLocation": "default",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_uint256",
+                    "typeString": "uint256"
+                  },
+                  "typeName": {
+                    "id": 1038,
+                    "name": "uint256",
+                    "nodeType": "ElementaryTypeName",
+                    "src": "27116:7:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_uint256",
+                      "typeString": "uint256"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                }
+              ],
+              "src": "27115:15:1"
+            },
+            "returnParameters": {
+              "id": 1043,
+              "nodeType": "ParameterList",
+              "parameters": [
+                {
+                  "constant": false,
+                  "id": 1042,
+                  "name": "",
+                  "nodeType": "VariableDeclaration",
+                  "scope": 1057,
+                  "src": "27152:7:1",
+                  "stateVariable": false,
+                  "storageLocation": "default",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_uint256",
+                    "typeString": "uint256"
+                  },
+                  "typeName": {
+                    "id": 1041,
+                    "name": "uint256",
+                    "nodeType": "ElementaryTypeName",
+                    "src": "27152:7:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_uint256",
+                      "typeString": "uint256"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                }
+              ],
+              "src": "27151:9:1"
+            },
+            "scope": 1302,
+            "src": "27094:196:1",
+            "stateMutability": "view",
+            "superFunction": 968,
+            "visibility": "public"
+          },
+          {
+            "body": {
+              "id": 1084,
+              "nodeType": "Block",
+              "src": "27740:164:1",
+              "statements": [
+                {
+                  "expression": {
+                    "argumentTypes": null,
+                    "arguments": [
+                      {
+                        "argumentTypes": null,
+                        "id": 1069,
+                        "name": "from",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 1059,
+                        "src": "27770:4:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        }
+                      },
+                      {
+                        "argumentTypes": null,
+                        "id": 1070,
+                        "name": "to",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 1061,
+                        "src": "27776:2:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        }
+                      },
+                      {
+                        "argumentTypes": null,
+                        "id": 1071,
+                        "name": "tokenId",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 1063,
+                        "src": "27780:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      }
+                    ],
+                    "expression": {
+                      "argumentTypes": [
+                        {
+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        },
+                        {
+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        },
+                        {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      ],
+                      "expression": {
+                        "argumentTypes": null,
+                        "id": 1066,
+                        "name": "super",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 1572,
+                        "src": "27750:5:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_super$_ERC721Enumerable_$1302",
+                          "typeString": "contract super ERC721Enumerable"
+                        }
+                      },
+                      "id": 1068,
+                      "isConstant": false,
+                      "isLValue": false,
+                      "isPure": false,
+                      "lValueRequested": false,
+                      "memberName": "_transferFrom",
+                      "nodeType": "MemberAccess",
+                      "referencedDeclaration": 880,
+                      "src": "27750:19:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_function_internal_nonpayable$_t_address_$_t_address_$_t_uint256_$returns$__$",
+                        "typeString": "function (address,address,uint256)"
+                      }
+                    },
+                    "id": 1072,
+                    "isConstant": false,
+                    "isLValue": false,
+                    "isPure": false,
+                    "kind": "functionCall",
+                    "lValueRequested": false,
+                    "names": [],
+                    "nodeType": "FunctionCall",
+                    "src": "27750:38:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_tuple$__$",
+                      "typeString": "tuple()"
+                    }
+                  },
+                  "id": 1073,
+                  "nodeType": "ExpressionStatement",
+                  "src": "27750:38:1"
+                },
+                {
+                  "expression": {
+                    "argumentTypes": null,
+                    "arguments": [
+                      {
+                        "argumentTypes": null,
+                        "id": 1075,
+                        "name": "from",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 1059,
+                        "src": "27832:4:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        }
+                      },
+                      {
+                        "argumentTypes": null,
+                        "id": 1076,
+                        "name": "tokenId",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 1063,
+                        "src": "27838:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      }
+                    ],
+                    "expression": {
+                      "argumentTypes": [
+                        {
+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        },
+                        {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      ],
+                      "id": 1074,
+                      "name": "_removeTokenFromOwnerEnumeration",
+                      "nodeType": "Identifier",
+                      "overloadedDeclarations": [],
+                      "referencedDeclaration": 1252,
+                      "src": "27799:32:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_function_internal_nonpayable$_t_address_$_t_uint256_$returns$__$",
+                        "typeString": "function (address,uint256)"
+                      }
+                    },
+                    "id": 1077,
+                    "isConstant": false,
+                    "isLValue": false,
+                    "isPure": false,
+                    "kind": "functionCall",
+                    "lValueRequested": false,
+                    "names": [],
+                    "nodeType": "FunctionCall",
+                    "src": "27799:47:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_tuple$__$",
+                      "typeString": "tuple()"
+                    }
+                  },
+                  "id": 1078,
+                  "nodeType": "ExpressionStatement",
+                  "src": "27799:47:1"
+                },
+                {
+                  "expression": {
+                    "argumentTypes": null,
+                    "arguments": [
+                      {
+                        "argumentTypes": null,
+                        "id": 1080,
+                        "name": "to",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 1061,
+                        "src": "27885:2:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        }
+                      },
+                      {
+                        "argumentTypes": null,
+                        "id": 1081,
+                        "name": "tokenId",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 1063,
+                        "src": "27889:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      }
+                    ],
+                    "expression": {
+                      "argumentTypes": [
+                        {
+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        },
+                        {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      ],
+                      "id": 1079,
+                      "name": "_addTokenToOwnerEnumeration",
+                      "nodeType": "Identifier",
+                      "overloadedDeclarations": [],
+                      "referencedDeclaration": 1176,
+                      "src": "27857:27:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_function_internal_nonpayable$_t_address_$_t_uint256_$returns$__$",
+                        "typeString": "function (address,uint256)"
+                      }
+                    },
+                    "id": 1082,
+                    "isConstant": false,
+                    "isLValue": false,
+                    "isPure": false,
+                    "kind": "functionCall",
+                    "lValueRequested": false,
+                    "names": [],
+                    "nodeType": "FunctionCall",
+                    "src": "27857:40:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_tuple$__$",
+                      "typeString": "tuple()"
+                    }
+                  },
+                  "id": 1083,
+                  "nodeType": "ExpressionStatement",
+                  "src": "27857:40:1"
+                }
+              ]
+            },
+            "documentation": "@dev Internal function to transfer ownership of a given token ID to another address.\nAs opposed to transferFrom, this imposes no restrictions on msg.sender.\n@param from current owner of the token\n@param to address to receive the ownership of the given token ID\n@param tokenId uint256 ID of the token to be transferred",
+            "id": 1085,
+            "implemented": true,
+            "kind": "function",
+            "modifiers": [],
+            "name": "_transferFrom",
+            "nodeType": "FunctionDefinition",
+            "parameters": {
+              "id": 1064,
+              "nodeType": "ParameterList",
+              "parameters": [
+                {
+                  "constant": false,
+                  "id": 1059,
+                  "name": "from",
+                  "nodeType": "VariableDeclaration",
+                  "scope": 1085,
+                  "src": "27688:12:1",
+                  "stateVariable": false,
+                  "storageLocation": "default",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_address",
+                    "typeString": "address"
+                  },
+                  "typeName": {
+                    "id": 1058,
+                    "name": "address",
+                    "nodeType": "ElementaryTypeName",
+                    "src": "27688:7:1",
+                    "stateMutability": "nonpayable",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_address",
+                      "typeString": "address"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                },
+                {
+                  "constant": false,
+                  "id": 1061,
+                  "name": "to",
+                  "nodeType": "VariableDeclaration",
+                  "scope": 1085,
+                  "src": "27702:10:1",
+                  "stateVariable": false,
+                  "storageLocation": "default",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_address",
+                    "typeString": "address"
+                  },
+                  "typeName": {
+                    "id": 1060,
+                    "name": "address",
+                    "nodeType": "ElementaryTypeName",
+                    "src": "27702:7:1",
+                    "stateMutability": "nonpayable",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_address",
+                      "typeString": "address"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                },
+                {
+                  "constant": false,
+                  "id": 1063,
+                  "name": "tokenId",
+                  "nodeType": "VariableDeclaration",
+                  "scope": 1085,
+                  "src": "27714:15:1",
+                  "stateVariable": false,
+                  "storageLocation": "default",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_uint256",
+                    "typeString": "uint256"
+                  },
+                  "typeName": {
+                    "id": 1062,
+                    "name": "uint256",
+                    "nodeType": "ElementaryTypeName",
+                    "src": "27714:7:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_uint256",
+                      "typeString": "uint256"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                }
+              ],
+              "src": "27687:43:1"
+            },
+            "returnParameters": {
+              "id": 1065,
+              "nodeType": "ParameterList",
+              "parameters": [],
+              "src": "27740:0:1"
+            },
+            "scope": 1302,
+            "src": "27665:239:1",
+            "stateMutability": "nonpayable",
+            "superFunction": 880,
+            "visibility": "internal"
+          },
+          {
+            "body": {
+              "id": 1108,
+              "nodeType": "Block",
+              "src": "28214:143:1",
+              "statements": [
+                {
+                  "expression": {
+                    "argumentTypes": null,
+                    "arguments": [
+                      {
+                        "argumentTypes": null,
+                        "id": 1095,
+                        "name": "to",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 1087,
+                        "src": "28236:2:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        }
+                      },
+                      {
+                        "argumentTypes": null,
+                        "id": 1096,
+                        "name": "tokenId",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 1089,
+                        "src": "28240:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      }
+                    ],
+                    "expression": {
+                      "argumentTypes": [
+                        {
+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        },
+                        {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      ],
+                      "expression": {
+                        "argumentTypes": null,
+                        "id": 1092,
+                        "name": "super",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 1572,
+                        "src": "28224:5:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_super$_ERC721Enumerable_$1302",
+                          "typeString": "contract super ERC721Enumerable"
+                        }
+                      },
+                      "id": 1094,
+                      "isConstant": false,
+                      "isLValue": false,
+                      "isPure": false,
+                      "lValueRequested": false,
+                      "memberName": "_mint",
+                      "nodeType": "MemberAccess",
+                      "referencedDeclaration": 768,
+                      "src": "28224:11:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_function_internal_nonpayable$_t_address_$_t_uint256_$returns$__$",
+                        "typeString": "function (address,uint256)"
+                      }
+                    },
+                    "id": 1097,
+                    "isConstant": false,
+                    "isLValue": false,
+                    "isPure": false,
+                    "kind": "functionCall",
+                    "lValueRequested": false,
+                    "names": [],
+                    "nodeType": "FunctionCall",
+                    "src": "28224:24:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_tuple$__$",
+                      "typeString": "tuple()"
+                    }
+                  },
+                  "id": 1098,
+                  "nodeType": "ExpressionStatement",
+                  "src": "28224:24:1"
+                },
+                {
+                  "expression": {
+                    "argumentTypes": null,
+                    "arguments": [
+                      {
+                        "argumentTypes": null,
+                        "id": 1100,
+                        "name": "to",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 1087,
+                        "src": "28287:2:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        }
+                      },
+                      {
+                        "argumentTypes": null,
+                        "id": 1101,
+                        "name": "tokenId",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 1089,
+                        "src": "28291:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      }
+                    ],
+                    "expression": {
+                      "argumentTypes": [
+                        {
+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        },
+                        {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      ],
+                      "id": 1099,
+                      "name": "_addTokenToOwnerEnumeration",
+                      "nodeType": "Identifier",
+                      "overloadedDeclarations": [],
+                      "referencedDeclaration": 1176,
+                      "src": "28259:27:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_function_internal_nonpayable$_t_address_$_t_uint256_$returns$__$",
+                        "typeString": "function (address,uint256)"
+                      }
+                    },
+                    "id": 1102,
+                    "isConstant": false,
+                    "isLValue": false,
+                    "isPure": false,
+                    "kind": "functionCall",
+                    "lValueRequested": false,
+                    "names": [],
+                    "nodeType": "FunctionCall",
+                    "src": "28259:40:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_tuple$__$",
+                      "typeString": "tuple()"
+                    }
+                  },
+                  "id": 1103,
+                  "nodeType": "ExpressionStatement",
+                  "src": "28259:40:1"
+                },
+                {
+                  "expression": {
+                    "argumentTypes": null,
+                    "arguments": [
+                      {
+                        "argumentTypes": null,
+                        "id": 1105,
+                        "name": "tokenId",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 1089,
+                        "src": "28342:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      }
+                    ],
+                    "expression": {
+                      "argumentTypes": [
+                        {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      ],
+                      "id": 1104,
+                      "name": "_addTokenToAllTokensEnumeration",
+                      "nodeType": "Identifier",
+                      "overloadedDeclarations": [],
+                      "referencedDeclaration": 1195,
+                      "src": "28310:31:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_function_internal_nonpayable$_t_uint256_$returns$__$",
+                        "typeString": "function (uint256)"
+                      }
+                    },
+                    "id": 1106,
+                    "isConstant": false,
+                    "isLValue": false,
+                    "isPure": false,
+                    "kind": "functionCall",
+                    "lValueRequested": false,
+                    "names": [],
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+                    "src": "28310:40:1",
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+                      "typeIdentifier": "t_tuple$__$",
+                      "typeString": "tuple()"
+                    }
+                  },
+                  "id": 1107,
+                  "nodeType": "ExpressionStatement",
+                  "src": "28310:40:1"
+                }
+              ]
+            },
+            "documentation": "@dev Internal function to mint a new token.\nReverts if the given token ID already exists.\n@param to address the beneficiary that will own the minted token\n@param tokenId uint256 ID of the token to be minted",
+            "id": 1109,
+            "implemented": true,
+            "kind": "function",
+            "modifiers": [],
+            "name": "_mint",
+            "nodeType": "FunctionDefinition",
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+              "parameters": [
+                {
+                  "constant": false,
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+                  "name": "to",
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+                  "scope": 1109,
+                  "src": "28176:10:1",
+                  "stateVariable": false,
+                  "storageLocation": "default",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_address",
+                    "typeString": "address"
+                  },
+                  "typeName": {
+                    "id": 1086,
+                    "name": "address",
+                    "nodeType": "ElementaryTypeName",
+                    "src": "28176:7:1",
+                    "stateMutability": "nonpayable",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_address",
+                      "typeString": "address"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                },
+                {
+                  "constant": false,
+                  "id": 1089,
+                  "name": "tokenId",
+                  "nodeType": "VariableDeclaration",
+                  "scope": 1109,
+                  "src": "28188:15:1",
+                  "stateVariable": false,
+                  "storageLocation": "default",
+                  "typeDescriptions": {
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+                      "typeString": "uint256"
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+            "visibility": "internal"
+          },
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+                        "src": "28710:5:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        }
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+                        "name": "tokenId",
+                        "nodeType": "Identifier",
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+                        "src": "28717:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
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+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        },
+                        {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
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+                        "src": "28698:5:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_super$_ERC721Enumerable_$1302",
+                          "typeString": "contract super ERC721Enumerable"
+                        }
+                      },
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+                      "isConstant": false,
+                      "isLValue": false,
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+                      "src": "28698:11:1",
+                      "typeDescriptions": {
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+                      }
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+                        "src": "28769:5:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        }
+                      },
+                      {
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+                        "id": 1125,
+                        "name": "tokenId",
+                        "nodeType": "Identifier",
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+                        "src": "28776:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      }
+                    ],
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+                      "argumentTypes": [
+                        {
+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        },
+                        {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      ],
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+                      "name": "_removeTokenFromOwnerEnumeration",
+                      "nodeType": "Identifier",
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+                      "src": "28736:32:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_function_internal_nonpayable$_t_address_$_t_uint256_$returns$__$",
+                        "typeString": "function (address,uint256)"
+                      }
+                    },
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+                    "isLValue": false,
+                    "isPure": false,
+                    "kind": "functionCall",
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+                    "nodeType": "FunctionCall",
+                    "src": "28736:48:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_tuple$__$",
+                      "typeString": "tuple()"
+                    }
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+                  "id": 1127,
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+                  "src": "28736:48:1"
+                },
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+                    "lValueRequested": false,
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+                      "baseExpression": {
+                        "argumentTypes": null,
+                        "id": 1128,
+                        "name": "_ownedTokensIndex",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 985,
+                        "src": "28903:17:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_mapping$_t_uint256_$_t_uint256_$",
+                          "typeString": "mapping(uint256 => uint256)"
+                        }
+                      },
+                      "id": 1130,
+                      "indexExpression": {
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+                        "id": 1129,
+                        "name": "tokenId",
+                        "nodeType": "Identifier",
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+                        "referencedDeclaration": 1113,
+                        "src": "28921:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      },
+                      "isConstant": false,
+                      "isLValue": true,
+                      "isPure": false,
+                      "lValueRequested": true,
+                      "nodeType": "IndexAccess",
+                      "src": "28903:26:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_uint256",
+                        "typeString": "uint256"
+                      }
+                    },
+                    "nodeType": "Assignment",
+                    "operator": "=",
+                    "rightHandSide": {
+                      "argumentTypes": null,
+                      "hexValue": "30",
+                      "id": 1131,
+                      "isConstant": false,
+                      "isLValue": false,
+                      "isPure": true,
+                      "kind": "number",
+                      "lValueRequested": false,
+                      "nodeType": "Literal",
+                      "src": "28932:1:1",
+                      "subdenomination": null,
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_rational_0_by_1",
+                        "typeString": "int_const 0"
+                      },
+                      "value": "0"
+                    },
+                    "src": "28903:30:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_uint256",
+                      "typeString": "uint256"
+                    }
+                  },
+                  "id": 1133,
+                  "nodeType": "ExpressionStatement",
+                  "src": "28903:30:1"
+                },
+                {
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+                    "argumentTypes": null,
+                    "arguments": [
+                      {
+                        "argumentTypes": null,
+                        "id": 1135,
+                        "name": "tokenId",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 1113,
+                        "src": "28981:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      }
+                    ],
+                    "expression": {
+                      "argumentTypes": [
+                        {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      ],
+                      "id": 1134,
+                      "name": "_removeTokenFromAllTokensEnumeration",
+                      "nodeType": "Identifier",
+                      "overloadedDeclarations": [],
+                      "referencedDeclaration": 1301,
+                      "src": "28944:36:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_function_internal_nonpayable$_t_uint256_$returns$__$",
+                        "typeString": "function (uint256)"
+                      }
+                    },
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+                    "isConstant": false,
+                    "isLValue": false,
+                    "isPure": false,
+                    "kind": "functionCall",
+                    "lValueRequested": false,
+                    "names": [],
+                    "nodeType": "FunctionCall",
+                    "src": "28944:45:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_tuple$__$",
+                      "typeString": "tuple()"
+                    }
+                  },
+                  "id": 1137,
+                  "nodeType": "ExpressionStatement",
+                  "src": "28944:45:1"
+                }
+              ]
+            },
+            "documentation": "@dev Internal function to burn a specific token.\nReverts if the token does not exist.\nDeprecated, use _burn(uint256) instead.\n@param owner owner of the token to burn\n@param tokenId uint256 ID of the token being burned",
+            "id": 1139,
+            "implemented": true,
+            "kind": "function",
+            "modifiers": [],
+            "name": "_burn",
+            "nodeType": "FunctionDefinition",
+            "parameters": {
+              "id": 1114,
+              "nodeType": "ParameterList",
+              "parameters": [
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+                  "id": 1111,
+                  "name": "owner",
+                  "nodeType": "VariableDeclaration",
+                  "scope": 1139,
+                  "src": "28647:13:1",
+                  "stateVariable": false,
+                  "storageLocation": "default",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_address",
+                    "typeString": "address"
+                  },
+                  "typeName": {
+                    "id": 1110,
+                    "name": "address",
+                    "nodeType": "ElementaryTypeName",
+                    "src": "28647:7:1",
+                    "stateMutability": "nonpayable",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_address",
+                      "typeString": "address"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                },
+                {
+                  "constant": false,
+                  "id": 1113,
+                  "name": "tokenId",
+                  "nodeType": "VariableDeclaration",
+                  "scope": 1139,
+                  "src": "28662:15:1",
+                  "stateVariable": false,
+                  "storageLocation": "default",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_uint256",
+                    "typeString": "uint256"
+                  },
+                  "typeName": {
+                    "id": 1112,
+                    "name": "uint256",
+                    "nodeType": "ElementaryTypeName",
+                    "src": "28662:7:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_uint256",
+                      "typeString": "uint256"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                }
+              ],
+              "src": "28646:32:1"
+            },
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+              "id": 1115,
+              "nodeType": "ParameterList",
+              "parameters": [],
+              "src": "28688:0:1"
+            },
+            "scope": 1302,
+            "src": "28632:364:1",
+            "stateMutability": "nonpayable",
+            "superFunction": 811,
+            "visibility": "internal"
+          },
+          {
+            "body": {
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+              "nodeType": "Block",
+              "src": "29282:43:1",
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+                    "baseExpression": {
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+                      "id": 1147,
+                      "name": "_ownedTokens",
+                      "nodeType": "Identifier",
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+                      "referencedDeclaration": 981,
+                      "src": "29299:12:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_mapping$_t_address_$_t_array$_t_uint256_$dyn_storage_$",
+                        "typeString": "mapping(address => uint256[] storage ref)"
+                      }
+                    },
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+                      "id": 1148,
+                      "name": "owner",
+                      "nodeType": "Identifier",
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+                      "referencedDeclaration": 1141,
+                      "src": "29312:5:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_address",
+                        "typeString": "address"
+                      }
+                    },
+                    "isConstant": false,
+                    "isLValue": true,
+                    "isPure": false,
+                    "lValueRequested": false,
+                    "nodeType": "IndexAccess",
+                    "src": "29299:19:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_array$_t_uint256_$dyn_storage",
+                      "typeString": "uint256[] storage ref"
+                    }
+                  },
+                  "functionReturnParameters": 1146,
+                  "id": 1150,
+                  "nodeType": "Return",
+                  "src": "29292:26:1"
+                }
+              ]
+            },
+            "documentation": "@dev Gets the list of token IDs of the requested owner.\n@param owner address owning the tokens\n@return uint256[] List of token IDs owned by the requested address",
+            "id": 1152,
+            "implemented": true,
+            "kind": "function",
+            "modifiers": [],
+            "name": "_tokensOfOwner",
+            "nodeType": "FunctionDefinition",
+            "parameters": {
+              "id": 1142,
+              "nodeType": "ParameterList",
+              "parameters": [
+                {
+                  "constant": false,
+                  "id": 1141,
+                  "name": "owner",
+                  "nodeType": "VariableDeclaration",
+                  "scope": 1152,
+                  "src": "29225:13:1",
+                  "stateVariable": false,
+                  "storageLocation": "default",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_address",
+                    "typeString": "address"
+                  },
+                  "typeName": {
+                    "id": 1140,
+                    "name": "address",
+                    "nodeType": "ElementaryTypeName",
+                    "src": "29225:7:1",
+                    "stateMutability": "nonpayable",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_address",
+                      "typeString": "address"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                }
+              ],
+              "src": "29224:15:1"
+            },
+            "returnParameters": {
+              "id": 1146,
+              "nodeType": "ParameterList",
+              "parameters": [
+                {
+                  "constant": false,
+                  "id": 1145,
+                  "name": "",
+                  "nodeType": "VariableDeclaration",
+                  "scope": 1152,
+                  "src": "29263:17:1",
+                  "stateVariable": false,
+                  "storageLocation": "storage",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_array$_t_uint256_$dyn_storage_ptr",
+                    "typeString": "uint256[]"
+                  },
+                  "typeName": {
+                    "baseType": {
+                      "id": 1143,
+                      "name": "uint256",
+                      "nodeType": "ElementaryTypeName",
+                      "src": "29263:7:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_uint256",
+                        "typeString": "uint256"
+                      }
+                    },
+                    "id": 1144,
+                    "length": null,
+                    "nodeType": "ArrayTypeName",
+                    "src": "29263:9:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_array$_t_uint256_$dyn_storage_ptr",
+                      "typeString": "uint256[]"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                }
+              ],
+              "src": "29262:19:1"
+            },
+            "scope": 1302,
+            "src": "29201:124:1",
+            "stateMutability": "view",
+            "superFunction": null,
+            "visibility": "internal"
+          },
+          {
+            "body": {
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+              "nodeType": "Block",
+              "src": "29693:109:1",
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+                        "id": 1159,
+                        "name": "_ownedTokensIndex",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 985,
+                        "src": "29703:17:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_mapping$_t_uint256_$_t_uint256_$",
+                          "typeString": "mapping(uint256 => uint256)"
+                        }
+                      },
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+                        "id": 1160,
+                        "name": "tokenId",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 1156,
+                        "src": "29721:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
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+                      "lValueRequested": true,
+                      "nodeType": "IndexAccess",
+                      "src": "29703:26:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_uint256",
+                        "typeString": "uint256"
+                      }
+                    },
+                    "nodeType": "Assignment",
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+                      "expression": {
+                        "argumentTypes": null,
+                        "baseExpression": {
+                          "argumentTypes": null,
+                          "id": 1162,
+                          "name": "_ownedTokens",
+                          "nodeType": "Identifier",
+                          "overloadedDeclarations": [],
+                          "referencedDeclaration": 981,
+                          "src": "29732:12:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_mapping$_t_address_$_t_array$_t_uint256_$dyn_storage_$",
+                            "typeString": "mapping(address => uint256[] storage ref)"
+                          }
+                        },
+                        "id": 1164,
+                        "indexExpression": {
+                          "argumentTypes": null,
+                          "id": 1163,
+                          "name": "to",
+                          "nodeType": "Identifier",
+                          "overloadedDeclarations": [],
+                          "referencedDeclaration": 1154,
+                          "src": "29745:2:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_address",
+                            "typeString": "address"
+                          }
+                        },
+                        "isConstant": false,
+                        "isLValue": true,
+                        "isPure": false,
+                        "lValueRequested": false,
+                        "nodeType": "IndexAccess",
+                        "src": "29732:16:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_array$_t_uint256_$dyn_storage",
+                          "typeString": "uint256[] storage ref"
+                        }
+                      },
+                      "id": 1165,
+                      "isConstant": false,
+                      "isLValue": true,
+                      "isPure": false,
+                      "lValueRequested": false,
+                      "memberName": "length",
+                      "nodeType": "MemberAccess",
+                      "referencedDeclaration": null,
+                      "src": "29732:23:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_uint256",
+                        "typeString": "uint256"
+                      }
+                    },
+                    "src": "29703:52:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_uint256",
+                      "typeString": "uint256"
+                    }
+                  },
+                  "id": 1167,
+                  "nodeType": "ExpressionStatement",
+                  "src": "29703:52:1"
+                },
+                {
+                  "expression": {
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+                    "arguments": [
+                      {
+                        "argumentTypes": null,
+                        "id": 1172,
+                        "name": "tokenId",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 1156,
+                        "src": "29787:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      }
+                    ],
+                    "expression": {
+                      "argumentTypes": [
+                        {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      ],
+                      "expression": {
+                        "argumentTypes": null,
+                        "baseExpression": {
+                          "argumentTypes": null,
+                          "id": 1168,
+                          "name": "_ownedTokens",
+                          "nodeType": "Identifier",
+                          "overloadedDeclarations": [],
+                          "referencedDeclaration": 981,
+                          "src": "29765:12:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_mapping$_t_address_$_t_array$_t_uint256_$dyn_storage_$",
+                            "typeString": "mapping(address => uint256[] storage ref)"
+                          }
+                        },
+                        "id": 1170,
+                        "indexExpression": {
+                          "argumentTypes": null,
+                          "id": 1169,
+                          "name": "to",
+                          "nodeType": "Identifier",
+                          "overloadedDeclarations": [],
+                          "referencedDeclaration": 1154,
+                          "src": "29778:2:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_address",
+                            "typeString": "address"
+                          }
+                        },
+                        "isConstant": false,
+                        "isLValue": true,
+                        "isPure": false,
+                        "lValueRequested": false,
+                        "nodeType": "IndexAccess",
+                        "src": "29765:16:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_array$_t_uint256_$dyn_storage",
+                          "typeString": "uint256[] storage ref"
+                        }
+                      },
+                      "id": 1171,
+                      "isConstant": false,
+                      "isLValue": false,
+                      "isPure": false,
+                      "lValueRequested": false,
+                      "memberName": "push",
+                      "nodeType": "MemberAccess",
+                      "referencedDeclaration": null,
+                      "src": "29765:21:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_function_arraypush_nonpayable$_t_uint256_$returns$_t_uint256_$",
+                        "typeString": "function (uint256) returns (uint256)"
+                      }
+                    },
+                    "id": 1173,
+                    "isConstant": false,
+                    "isLValue": false,
+                    "isPure": false,
+                    "kind": "functionCall",
+                    "lValueRequested": false,
+                    "names": [],
+                    "nodeType": "FunctionCall",
+                    "src": "29765:30:1",
+                    "typeDescriptions": {
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+                              "referencedDeclaration": 1213,
+                              "src": "31387:10:1",
+                              "typeDescriptions": {
+                                "typeIdentifier": "t_uint256",
+                                "typeString": "uint256"
+                              }
+                            },
+                            "isConstant": false,
+                            "isLValue": true,
+                            "isPure": false,
+                            "lValueRequested": true,
+                            "nodeType": "IndexAccess",
+                            "src": "31368:30:1",
+                            "typeDescriptions": {
+                              "typeIdentifier": "t_uint256",
+                              "typeString": "uint256"
+                            }
+                          },
+                          "nodeType": "Assignment",
+                          "operator": "=",
+                          "rightHandSide": {
+                            "argumentTypes": null,
+                            "id": 1234,
+                            "name": "lastTokenId",
+                            "nodeType": "Identifier",
+                            "overloadedDeclarations": [],
+                            "referencedDeclaration": 1222,
+                            "src": "31401:11:1",
+                            "typeDescriptions": {
+                              "typeIdentifier": "t_uint256",
+                              "typeString": "uint256"
+                            }
+                          },
+                          "src": "31368:44:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_uint256",
+                            "typeString": "uint256"
+                          }
+                        },
+                        "id": 1236,
+                        "nodeType": "ExpressionStatement",
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+                      },
+                      {
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+                          "argumentTypes": null,
+                          "id": 1241,
+                          "isConstant": false,
+                          "isLValue": false,
+                          "isPure": false,
+                          "lValueRequested": false,
+                          "leftHandSide": {
+                            "argumentTypes": null,
+                            "baseExpression": {
+                              "argumentTypes": null,
+                              "id": 1237,
+                              "name": "_ownedTokensIndex",
+                              "nodeType": "Identifier",
+                              "overloadedDeclarations": [],
+                              "referencedDeclaration": 985,
+                              "src": "31484:17:1",
+                              "typeDescriptions": {
+                                "typeIdentifier": "t_mapping$_t_uint256_$_t_uint256_$",
+                                "typeString": "mapping(uint256 => uint256)"
+                              }
+                            },
+                            "id": 1239,
+                            "indexExpression": {
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+                              "id": 1238,
+                              "name": "lastTokenId",
+                              "nodeType": "Identifier",
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+                              "referencedDeclaration": 1222,
+                              "src": "31502:11:1",
+                              "typeDescriptions": {
+                                "typeIdentifier": "t_uint256",
+                                "typeString": "uint256"
+                              }
+                            },
+                            "isConstant": false,
+                            "isLValue": true,
+                            "isPure": false,
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+                            "nodeType": "IndexAccess",
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+                              "typeIdentifier": "t_uint256",
+                              "typeString": "uint256"
+                            }
+                          },
+                          "nodeType": "Assignment",
+                          "operator": "=",
+                          "rightHandSide": {
+                            "argumentTypes": null,
+                            "id": 1240,
+                            "name": "tokenIndex",
+                            "nodeType": "Identifier",
+                            "overloadedDeclarations": [],
+                            "referencedDeclaration": 1213,
+                            "src": "31517:10:1",
+                            "typeDescriptions": {
+                              "typeIdentifier": "t_uint256",
+                              "typeString": "uint256"
+                            }
+                          },
+                          "src": "31484:43:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_uint256",
+                            "typeString": "uint256"
+                          }
+                        },
+                        "id": 1242,
+                        "nodeType": "ExpressionStatement",
+                        "src": "31484:43:1"
+                      }
+                    ]
+                  }
+                },
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+                    "isConstant": false,
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+                    "isPure": false,
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+                      "expression": {
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+                        "baseExpression": {
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+                          "id": 1245,
+                          "name": "_ownedTokens",
+                          "nodeType": "Identifier",
+                          "overloadedDeclarations": [],
+                          "referencedDeclaration": 981,
+                          "src": "31658:12:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_mapping$_t_address_$_t_array$_t_uint256_$dyn_storage_$",
+                            "typeString": "mapping(address => uint256[] storage ref)"
+                          }
+                        },
+                        "id": 1247,
+                        "indexExpression": {
+                          "argumentTypes": null,
+                          "id": 1246,
+                          "name": "from",
+                          "nodeType": "Identifier",
+                          "overloadedDeclarations": [],
+                          "referencedDeclaration": 1197,
+                          "src": "31671:4:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_address",
+                            "typeString": "address"
+                          }
+                        },
+                        "isConstant": false,
+                        "isLValue": true,
+                        "isPure": false,
+                        "lValueRequested": false,
+                        "nodeType": "IndexAccess",
+                        "src": "31658:18:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_array$_t_uint256_$dyn_storage",
+                          "typeString": "uint256[] storage ref"
+                        }
+                      },
+                      "id": 1248,
+                      "isConstant": false,
+                      "isLValue": true,
+                      "isPure": false,
+                      "lValueRequested": true,
+                      "memberName": "length",
+                      "nodeType": "MemberAccess",
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+                      "src": "31658:25:1",
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+                        "typeString": "uint256"
+                      }
+                    },
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+                      "typeString": "uint256"
+                    }
+                  },
+                  "id": 1250,
+                  "nodeType": "ExpressionStatement",
+                  "src": "31658:27:1"
+                }
+              ]
+            },
+            "documentation": "@dev Private function to remove a token from this extension's ownership-tracking data structures. Note that\nwhile the token is not assigned a new owner, the _ownedTokensIndex mapping is _not_ updated: this allows for\ngas optimizations e.g. when performing a transfer operation (avoiding double writes).\nThis has O(1) time complexity, but alters the order of the _ownedTokens array.\n@param from address representing the previous owner of the given token ID\n@param tokenId uint256 ID of the token to be removed from the tokens list of the given address",
+            "id": 1252,
+            "implemented": true,
+            "kind": "function",
+            "modifiers": [],
+            "name": "_removeTokenFromOwnerEnumeration",
+            "nodeType": "FunctionDefinition",
+            "parameters": {
+              "id": 1200,
+              "nodeType": "ParameterList",
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+                  "id": 1197,
+                  "name": "from",
+                  "nodeType": "VariableDeclaration",
+                  "scope": 1252,
+                  "src": "30815:12:1",
+                  "stateVariable": false,
+                  "storageLocation": "default",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_address",
+                    "typeString": "address"
+                  },
+                  "typeName": {
+                    "id": 1196,
+                    "name": "address",
+                    "nodeType": "ElementaryTypeName",
+                    "src": "30815:7:1",
+                    "stateMutability": "nonpayable",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_address",
+                      "typeString": "address"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                },
+                {
+                  "constant": false,
+                  "id": 1199,
+                  "name": "tokenId",
+                  "nodeType": "VariableDeclaration",
+                  "scope": 1252,
+                  "src": "30829:15:1",
+                  "stateVariable": false,
+                  "storageLocation": "default",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_uint256",
+                    "typeString": "uint256"
+                  },
+                  "typeName": {
+                    "id": 1198,
+                    "name": "uint256",
+                    "nodeType": "ElementaryTypeName",
+                    "src": "30829:7:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_uint256",
+                      "typeString": "uint256"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                }
+              ],
+              "src": "30814:31:1"
+            },
+            "returnParameters": {
+              "id": 1201,
+              "nodeType": "ParameterList",
+              "parameters": [],
+              "src": "30854:0:1"
+            },
+            "scope": 1302,
+            "src": "30773:1128:1",
+            "stateMutability": "nonpayable",
+            "superFunction": null,
+            "visibility": "private"
+          },
+          {
+            "body": {
+              "id": 1300,
+              "nodeType": "Block",
+              "src": "32260:993:1",
+              "statements": [
+                {
+                  "assignments": [
+                    1258
+                  ],
+                  "declarations": [
+                    {
+                      "constant": false,
+                      "id": 1258,
+                      "name": "lastTokenIndex",
+                      "nodeType": "VariableDeclaration",
+                      "scope": 1300,
+                      "src": "32438:22:1",
+                      "stateVariable": false,
+                      "storageLocation": "default",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_uint256",
+                        "typeString": "uint256"
+                      },
+                      "typeName": {
+                        "id": 1257,
+                        "name": "uint256",
+                        "nodeType": "ElementaryTypeName",
+                        "src": "32438:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      },
+                      "value": null,
+                      "visibility": "internal"
+                    }
+                  ],
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+                  "initialValue": {
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+                    "arguments": [
+                      {
+                        "argumentTypes": null,
+                        "hexValue": "31",
+                        "id": 1262,
+                        "isConstant": false,
+                        "isLValue": false,
+                        "isPure": true,
+                        "kind": "number",
+                        "lValueRequested": false,
+                        "nodeType": "Literal",
+                        "src": "32485:1:1",
+                        "subdenomination": null,
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_rational_1_by_1",
+                          "typeString": "int_const 1"
+                        },
+                        "value": "1"
+                      }
+                    ],
+                    "expression": {
+                      "argumentTypes": [
+                        {
+                          "typeIdentifier": "t_rational_1_by_1",
+                          "typeString": "int_const 1"
+                        }
+                      ],
+                      "expression": {
+                        "argumentTypes": null,
+                        "expression": {
+                          "argumentTypes": null,
+                          "id": 1259,
+                          "name": "_allTokens",
+                          "nodeType": "Identifier",
+                          "overloadedDeclarations": [],
+                          "referencedDeclaration": 988,
+                          "src": "32463:10:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_array$_t_uint256_$dyn_storage",
+                            "typeString": "uint256[] storage ref"
+                          }
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+                        "isLValue": true,
+                        "isPure": false,
+                        "lValueRequested": false,
+                        "memberName": "length",
+                        "nodeType": "MemberAccess",
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+                        "src": "32463:17:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
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+                      "isLValue": false,
+                      "isPure": false,
+                      "lValueRequested": false,
+                      "memberName": "sub",
+                      "nodeType": "MemberAccess",
+                      "referencedDeclaration": 190,
+                      "src": "32463:21:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_function_internal_pure$_t_uint256_$_t_uint256_$returns$_t_uint256_$bound_to$_t_uint256_$",
+                        "typeString": "function (uint256,uint256) pure returns (uint256)"
+                      }
+                    },
+                    "id": 1263,
+                    "isConstant": false,
+                    "isLValue": false,
+                    "isPure": false,
+                    "kind": "functionCall",
+                    "lValueRequested": false,
+                    "names": [],
+                    "nodeType": "FunctionCall",
+                    "src": "32463:24:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_uint256",
+                      "typeString": "uint256"
+                    }
+                  },
+                  "nodeType": "VariableDeclarationStatement",
+                  "src": "32438:49:1"
+                },
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+                      "id": 1266,
+                      "name": "tokenIndex",
+                      "nodeType": "VariableDeclaration",
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+                      "src": "32497:18:1",
+                      "stateVariable": false,
+                      "storageLocation": "default",
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+                        "typeIdentifier": "t_uint256",
+                        "typeString": "uint256"
+                      },
+                      "typeName": {
+                        "id": 1265,
+                        "name": "uint256",
+                        "nodeType": "ElementaryTypeName",
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+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      },
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+                      "visibility": "internal"
+                    }
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+                  "initialValue": {
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+                      "id": 1267,
+                      "name": "_allTokensIndex",
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+                      "src": "32518:15:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_mapping$_t_uint256_$_t_uint256_$",
+                        "typeString": "mapping(uint256 => uint256)"
+                      }
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+                    "indexExpression": {
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+                      "id": 1268,
+                      "name": "tokenId",
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+                      "src": "32534:7:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_uint256",
+                        "typeString": "uint256"
+                      }
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+                    "isPure": false,
+                    "lValueRequested": false,
+                    "nodeType": "IndexAccess",
+                    "src": "32518:24:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_uint256",
+                      "typeString": "uint256"
+                    }
+                  },
+                  "nodeType": "VariableDeclarationStatement",
+                  "src": "32497:45:1"
+                },
+                {
+                  "assignments": [
+                    1272
+                  ],
+                  "declarations": [
+                    {
+                      "constant": false,
+                      "id": 1272,
+                      "name": "lastTokenId",
+                      "nodeType": "VariableDeclaration",
+                      "scope": 1300,
+                      "src": "32864:19:1",
+                      "stateVariable": false,
+                      "storageLocation": "default",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_uint256",
+                        "typeString": "uint256"
+                      },
+                      "typeName": {
+                        "id": 1271,
+                        "name": "uint256",
+                        "nodeType": "ElementaryTypeName",
+                        "src": "32864:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      },
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+                      "visibility": "internal"
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+                      "src": "32886:10:1",
+                      "typeDescriptions": {
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+                        "typeString": "uint256[] storage ref"
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+                      "id": 1274,
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+                      "src": "32897:14:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_uint256",
+                        "typeString": "uint256"
+                      }
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+                    "nodeType": "IndexAccess",
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+                      "typeIdentifier": "t_uint256",
+                      "typeString": "uint256"
+                    }
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+                        "src": "32923:10:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_array$_t_uint256_$dyn_storage",
+                          "typeString": "uint256[] storage ref"
+                        }
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+                        "typeString": "uint256"
+                      }
+                    },
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+                        "typeIdentifier": "t_uint256",
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+                        "src": "33027:15:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_mapping$_t_uint256_$_t_uint256_$",
+                          "typeString": "mapping(uint256 => uint256)"
+                        }
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+                        "src": "33189:10:1",
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+                            "typeString": "address"
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+                        "id": 911,
+                        "name": "_data",
+                        "nodeType": "Identifier",
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+                        "src": "23657:5:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_bytes_memory_ptr",
+                          "typeString": "bytes memory"
+                        }
+                      }
+                    ],
+                    "expression": {
+                      "argumentTypes": [
+                        {
+                          "typeIdentifier": "t_address_payable",
+                          "typeString": "address payable"
+                        },
+                        {
+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        },
+                        {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        },
+                        {
+                          "typeIdentifier": "t_bytes_memory_ptr",
+                          "typeString": "bytes memory"
+                        }
+                      ],
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+                        "arguments": [
+                          {
+                            "argumentTypes": null,
+                            "id": 904,
+                            "name": "to",
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+                            "src": "23609:2:1",
+                            "typeDescriptions": {
+                              "typeIdentifier": "t_address",
+                              "typeString": "address"
+                            }
+                          }
+                        ],
+                        "expression": {
+                          "argumentTypes": [
+                            {
+                              "typeIdentifier": "t_address",
+                              "typeString": "address"
+                            }
+                          ],
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+                          "name": "IERC721Receiver",
+                          "nodeType": "Identifier",
+                          "overloadedDeclarations": [],
+                          "referencedDeclaration": 139,
+                          "src": "23593:15:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_type$_t_contract$_IERC721Receiver_$139_$",
+                            "typeString": "type(contract IERC721Receiver)"
+                          }
+                        },
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+                        "isPure": false,
+                        "kind": "typeConversion",
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+                        "nodeType": "FunctionCall",
+                        "src": "23593:19:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_contract$_IERC721Receiver_$139",
+                          "typeString": "contract IERC721Receiver"
+                        }
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+                      "lValueRequested": false,
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+                        "typeString": "function (address,address,uint256,bytes memory) external returns (bytes4)"
+                      }
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+                    "isConstant": false,
+                    "isLValue": false,
+                    "isPure": false,
+                    "kind": "functionCall",
+                    "lValueRequested": false,
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+                    "nodeType": "FunctionCall",
+                    "src": "23593:70:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_bytes4",
+                      "typeString": "bytes4"
+                    }
+                  },
+                  "nodeType": "VariableDeclarationStatement",
+                  "src": "23577:86:1"
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+                    "components": [
+                      {
+                        "argumentTypes": null,
+                        "commonType": {
+                          "typeIdentifier": "t_bytes4",
+                          "typeString": "bytes4"
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+                        "isPure": false,
+                        "lValueRequested": false,
+                        "leftExpression": {
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+                          "id": 914,
+                          "name": "retval",
+                          "nodeType": "Identifier",
+                          "overloadedDeclarations": [],
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+                          "src": "23681:6:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_bytes4",
+                            "typeString": "bytes4"
+                          }
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+                        "operator": "==",
+                        "rightExpression": {
+                          "argumentTypes": null,
+                          "id": 915,
+                          "name": "_ERC721_RECEIVED",
+                          "nodeType": "Identifier",
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+                          "referencedDeclaration": 403,
+                          "src": "23691:16:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_bytes4",
+                            "typeString": "bytes4"
+                          }
+                        },
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+                          "typeIdentifier": "t_bool",
+                          "typeString": "bool"
+                        }
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+                }
+              ]
+            },
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+                  "visibility": "internal"
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+                      "typeString": "uint256"
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+                  "visibility": "internal"
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+                      "typeString": "bytes"
+                    }
+                  },
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+                  "visibility": "internal"
+                }
+              ],
+              "src": "23399:63:1"
+            },
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+              "nodeType": "ParameterList",
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+                  "name": "",
+                  "nodeType": "VariableDeclaration",
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+                  "src": "23489:4:1",
+                  "stateVariable": false,
+                  "storageLocation": "default",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_bool",
+                    "typeString": "bool"
+                  },
+                  "typeName": {
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+                    "name": "bool",
+                    "nodeType": "ElementaryTypeName",
+                    "src": "23489:4:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_bool",
+                      "typeString": "bool"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                }
+              ],
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+            "src": "23368:347:1",
+            "stateMutability": "nonpayable",
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+            "visibility": "internal"
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+                    "commonType": {
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+                        "id": 925,
+                        "name": "_tokenApprovals",
+                        "nodeType": "Identifier",
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+                        "referencedDeclaration": 411,
+                        "src": "23940:15:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_mapping$_t_uint256_$_t_address_$",
+                          "typeString": "mapping(uint256 => address)"
+                        }
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+                        "id": 926,
+                        "name": "tokenId",
+                        "nodeType": "Identifier",
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+                        "referencedDeclaration": 922,
+                        "src": "23956:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
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+                        "typeString": "address"
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+                      "arguments": [
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+                          "argumentTypes": null,
+                          "hexValue": "30",
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+                          "isLValue": false,
+                          "isPure": true,
+                          "kind": "number",
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+                          "nodeType": "Literal",
+                          "src": "23976:1:1",
+                          "subdenomination": null,
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_rational_0_by_1",
+                            "typeString": "int_const 0"
+                          },
+                          "value": "0"
+                        }
+                      ],
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+                        "argumentTypes": [
+                          {
+                            "typeIdentifier": "t_rational_0_by_1",
+                            "typeString": "int_const 0"
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+                        "isConstant": false,
+                        "isLValue": false,
+                        "isPure": true,
+                        "lValueRequested": false,
+                        "nodeType": "ElementaryTypeNameExpression",
+                        "src": "23968:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_type$_t_address_$",
+                          "typeString": "type(address)"
+                        },
+                        "typeName": "address"
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+                      "names": [],
+                      "nodeType": "FunctionCall",
+                      "src": "23968:10:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_address_payable",
+                        "typeString": "address payable"
+                      }
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+                    "typeDescriptions": {
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+                      "typeString": "bool"
+                    }
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+                  "nodeType": "IfStatement",
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+                          "isLValue": false,
+                          "isPure": false,
+                          "lValueRequested": false,
+                          "leftHandSide": {
+                            "argumentTypes": null,
+                            "baseExpression": {
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+                              "id": 932,
+                              "name": "_tokenApprovals",
+                              "nodeType": "Identifier",
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+                              "referencedDeclaration": 411,
+                              "src": "23994:15:1",
+                              "typeDescriptions": {
+                                "typeIdentifier": "t_mapping$_t_uint256_$_t_address_$",
+                                "typeString": "mapping(uint256 => address)"
+                              }
+                            },
+                            "id": 934,
+                            "indexExpression": {
+                              "argumentTypes": null,
+                              "id": 933,
+                              "name": "tokenId",
+                              "nodeType": "Identifier",
+                              "overloadedDeclarations": [],
+                              "referencedDeclaration": 922,
+                              "src": "24010:7:1",
+                              "typeDescriptions": {
+                                "typeIdentifier": "t_uint256",
+                                "typeString": "uint256"
+                              }
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+                            "isLValue": true,
+                            "isPure": false,
+                            "lValueRequested": true,
+                            "nodeType": "IndexAccess",
+                            "src": "23994:24:1",
+                            "typeDescriptions": {
+                              "typeIdentifier": "t_address",
+                              "typeString": "address"
+                            }
+                          },
+                          "nodeType": "Assignment",
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+                          "rightHandSide": {
+                            "argumentTypes": null,
+                            "arguments": [
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+                                "argumentTypes": null,
+                                "hexValue": "30",
+                                "id": 936,
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+                                "isLValue": false,
+                                "isPure": true,
+                                "kind": "number",
+                                "lValueRequested": false,
+                                "nodeType": "Literal",
+                                "src": "24029:1:1",
+                                "subdenomination": null,
+                                "typeDescriptions": {
+                                  "typeIdentifier": "t_rational_0_by_1",
+                                  "typeString": "int_const 0"
+                                },
+                                "value": "0"
+                              }
+                            ],
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+                              "argumentTypes": [
+                                {
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+                                  "typeString": "int_const 0"
+                                }
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+                              "isLValue": false,
+                              "isPure": true,
+                              "lValueRequested": false,
+                              "nodeType": "ElementaryTypeNameExpression",
+                              "src": "24021:7:1",
+                              "typeDescriptions": {
+                                "typeIdentifier": "t_type$_t_address_$",
+                                "typeString": "type(address)"
+                              },
+                              "typeName": "address"
+                            },
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+                            "isLValue": false,
+                            "isPure": true,
+                            "kind": "typeConversion",
+                            "lValueRequested": false,
+                            "names": [],
+                            "nodeType": "FunctionCall",
+                            "src": "24021:10:1",
+                            "typeDescriptions": {
+                              "typeIdentifier": "t_address_payable",
+                              "typeString": "address payable"
+                            }
+                          },
+                          "src": "23994:37:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_address",
+                            "typeString": "address"
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+                        "nodeType": "ExpressionStatement",
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+                      }
+                    ]
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+                }
+              ]
+            },
+            "documentation": "@dev Private function to clear current approval of a given token ID.\n@param tokenId uint256 ID of the token to be transferred",
+            "id": 943,
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+            "kind": "function",
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+                  "storageLocation": "default",
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+                    "name": "uint256",
+                    "nodeType": "ElementaryTypeName",
+                    "src": "23901:7:1",
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+                  "visibility": "internal"
+                }
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+            },
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+              "src": "23926:0:1"
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+            "visibility": "private"
+          }
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+      {
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+        "literals": [
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+        "nodeType": "PragmaDirective",
+        "src": "24121:23:1"
+      },
+      {
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+            "baseName": {
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+              "id": 946,
+              "name": "IERC721",
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+              "src": "24314:7:1",
+              "typeDescriptions": {
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+                "typeString": "contract IERC721"
+              }
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+            "nodeType": "InheritanceSpecifier",
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+        ],
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+        ],
+        "contractKind": "contract",
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+        "id": 969,
+        "linearizedBaseContracts": [
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+        "name": "IERC721Enumerable",
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+            "stateMutability": "view",
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+                        "typeString": "uint256[] storage ref"
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+                      "nodeType": "Identifier",
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+                      "src": "26496:5:1",
+                      "typeDescriptions": {
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+                  "storageLocation": "default",
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+                    "typeString": "address"
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+                    "name": "address",
+                    "nodeType": "ElementaryTypeName",
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+                    "stateMutability": "nonpayable",
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+                      "typeString": "address"
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+                      "nodeType": "Identifier",
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+                      "src": "26732:10:1",
+                      "typeDescriptions": {
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+                    "memberName": "length",
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+                    "src": "26732:17:1",
+                    "typeDescriptions": {
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+                  "nodeType": "Return",
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+                }
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+            "implemented": true,
+            "kind": "function",
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+                      "typeString": "uint256"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                }
+              ],
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+            },
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+            "src": "26662:94:1",
+            "stateMutability": "view",
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+                        "commonType": {
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+                          "id": 1045,
+                          "name": "index",
+                          "nodeType": "Identifier",
+                          "overloadedDeclarations": [],
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+                          "src": "27179:5:1",
+                          "typeDescriptions": {
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+                            "typeString": "uint256"
+                          }
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+                        "operator": "<",
+                        "rightExpression": {
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+                          "arguments": [],
+                          "expression": {
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+                            "id": 1046,
+                            "name": "totalSupply",
+                            "nodeType": "Identifier",
+                            "overloadedDeclarations": [
+                              1037
+                            ],
+                            "referencedDeclaration": 1037,
+                            "src": "27187:11:1",
+                            "typeDescriptions": {
+                              "typeIdentifier": "t_function_internal_view$__$returns$_t_uint256_$",
+                              "typeString": "function () view returns (uint256)"
+                            }
+                          },
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+                          "isConstant": false,
+                          "isLValue": false,
+                          "isPure": false,
+                          "kind": "functionCall",
+                          "lValueRequested": false,
+                          "names": [],
+                          "nodeType": "FunctionCall",
+                          "src": "27187:13:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_uint256",
+                            "typeString": "uint256"
+                          }
+                        },
+                        "src": "27179:21:1",
+                        "typeDescriptions": {
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+                          "typeString": "bool"
+                        }
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+                        "isPure": true,
+                        "kind": "string",
+                        "lValueRequested": false,
+                        "nodeType": "Literal",
+                        "src": "27202:46:1",
+                        "subdenomination": null,
+                        "typeDescriptions": {
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+                          "typeString": "literal_string \"ERC721Enumerable: global index out of bounds\""
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+                        "value": "ERC721Enumerable: global index out of bounds"
+                      }
+                    ],
+                    "expression": {
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+                          "typeString": "bool"
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+                      "src": "27171:7:1",
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+                        "typeString": "function (bool,string memory) pure"
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+                    "kind": "functionCall",
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+                    "baseExpression": {
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+                      "id": 1052,
+                      "name": "_allTokens",
+                      "nodeType": "Identifier",
+                      "overloadedDeclarations": [],
+                      "referencedDeclaration": 988,
+                      "src": "27266:10:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_array$_t_uint256_$dyn_storage",
+                        "typeString": "uint256[] storage ref"
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+                    "id": 1054,
+                    "indexExpression": {
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+                      "id": 1053,
+                      "name": "index",
+                      "nodeType": "Identifier",
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+                      "referencedDeclaration": 1039,
+                      "src": "27277:5:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_uint256",
+                        "typeString": "uint256"
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+                      "typeString": "uint256"
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+                  "nodeType": "Return",
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+                }
+              ]
+            },
+            "documentation": "@dev Gets the token ID at a given index of all the tokens in this contract\nReverts if the index is greater or equal to the total number of tokens.\n@param index uint256 representing the index to be accessed of the tokens list\n@return uint256 token ID at the given index of the tokens list",
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+            "implemented": true,
+            "kind": "function",
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+                  "stateVariable": false,
+                  "storageLocation": "default",
+                  "typeDescriptions": {
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+                    "typeString": "uint256"
+                  },
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+                    "name": "uint256",
+                    "nodeType": "ElementaryTypeName",
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+                    "typeDescriptions": {
+                      "typeIdentifier": "t_uint256",
+                      "typeString": "uint256"
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+                  "value": null,
+                  "visibility": "internal"
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+                  "nodeType": "VariableDeclaration",
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+                  "storageLocation": "default",
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+                        "referencedDeclaration": 1059,
+                        "src": "27770:4:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        }
+                      },
+                      {
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+                        "id": 1070,
+                        "name": "to",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 1061,
+                        "src": "27776:2:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        }
+                      },
+                      {
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+                        "id": 1071,
+                        "name": "tokenId",
+                        "nodeType": "Identifier",
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+                        "referencedDeclaration": 1063,
+                        "src": "27780:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      }
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+                      "argumentTypes": [
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+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
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+                        {
+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        },
+                        {
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+                        "name": "super",
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+                        "src": "27750:5:1",
+                        "typeDescriptions": {
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+                          "typeString": "contract super ERC721Enumerable"
+                        }
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+                        "src": "27832:4:1",
+                        "typeDescriptions": {
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+                          "typeString": "address"
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+                      {
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+                        "id": 1076,
+                        "name": "tokenId",
+                        "nodeType": "Identifier",
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+                          "typeString": "address"
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+                          "typeString": "uint256"
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+                        "name": "to",
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+                        "src": "27885:2:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        }
+                      },
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+                        "id": 1081,
+                        "name": "tokenId",
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+                          "typeString": "address"
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+                          "typeString": "uint256"
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+                      "src": "27857:27:1",
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+              ]
+            },
+            "documentation": "@dev Internal function to transfer ownership of a given token ID to another address.\nAs opposed to transferFrom, this imposes no restrictions on msg.sender.\n@param from current owner of the token\n@param to address to receive the ownership of the given token ID\n@param tokenId uint256 ID of the token to be transferred",
+            "id": 1085,
+            "implemented": true,
+            "kind": "function",
+            "modifiers": [],
+            "name": "_transferFrom",
+            "nodeType": "FunctionDefinition",
+            "parameters": {
+              "id": 1064,
+              "nodeType": "ParameterList",
+              "parameters": [
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+                  "id": 1059,
+                  "name": "from",
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+                  "scope": 1085,
+                  "src": "27688:12:1",
+                  "stateVariable": false,
+                  "storageLocation": "default",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_address",
+                    "typeString": "address"
+                  },
+                  "typeName": {
+                    "id": 1058,
+                    "name": "address",
+                    "nodeType": "ElementaryTypeName",
+                    "src": "27688:7:1",
+                    "stateMutability": "nonpayable",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_address",
+                      "typeString": "address"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                },
+                {
+                  "constant": false,
+                  "id": 1061,
+                  "name": "to",
+                  "nodeType": "VariableDeclaration",
+                  "scope": 1085,
+                  "src": "27702:10:1",
+                  "stateVariable": false,
+                  "storageLocation": "default",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_address",
+                    "typeString": "address"
+                  },
+                  "typeName": {
+                    "id": 1060,
+                    "name": "address",
+                    "nodeType": "ElementaryTypeName",
+                    "src": "27702:7:1",
+                    "stateMutability": "nonpayable",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_address",
+                      "typeString": "address"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                },
+                {
+                  "constant": false,
+                  "id": 1063,
+                  "name": "tokenId",
+                  "nodeType": "VariableDeclaration",
+                  "scope": 1085,
+                  "src": "27714:15:1",
+                  "stateVariable": false,
+                  "storageLocation": "default",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_uint256",
+                    "typeString": "uint256"
+                  },
+                  "typeName": {
+                    "id": 1062,
+                    "name": "uint256",
+                    "nodeType": "ElementaryTypeName",
+                    "src": "27714:7:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_uint256",
+                      "typeString": "uint256"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                }
+              ],
+              "src": "27687:43:1"
+            },
+            "returnParameters": {
+              "id": 1065,
+              "nodeType": "ParameterList",
+              "parameters": [],
+              "src": "27740:0:1"
+            },
+            "scope": 1302,
+            "src": "27665:239:1",
+            "stateMutability": "nonpayable",
+            "superFunction": 880,
+            "visibility": "internal"
+          },
+          {
+            "body": {
+              "id": 1108,
+              "nodeType": "Block",
+              "src": "28214:143:1",
+              "statements": [
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+                    "argumentTypes": null,
+                    "arguments": [
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+                        "argumentTypes": null,
+                        "id": 1095,
+                        "name": "to",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 1087,
+                        "src": "28236:2:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        }
+                      },
+                      {
+                        "argumentTypes": null,
+                        "id": 1096,
+                        "name": "tokenId",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 1089,
+                        "src": "28240:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      }
+                    ],
+                    "expression": {
+                      "argumentTypes": [
+                        {
+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        },
+                        {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      ],
+                      "expression": {
+                        "argumentTypes": null,
+                        "id": 1092,
+                        "name": "super",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 1572,
+                        "src": "28224:5:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_super$_ERC721Enumerable_$1302",
+                          "typeString": "contract super ERC721Enumerable"
+                        }
+                      },
+                      "id": 1094,
+                      "isConstant": false,
+                      "isLValue": false,
+                      "isPure": false,
+                      "lValueRequested": false,
+                      "memberName": "_mint",
+                      "nodeType": "MemberAccess",
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+                      "src": "28224:11:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_function_internal_nonpayable$_t_address_$_t_uint256_$returns$__$",
+                        "typeString": "function (address,uint256)"
+                      }
+                    },
+                    "id": 1097,
+                    "isConstant": false,
+                    "isLValue": false,
+                    "isPure": false,
+                    "kind": "functionCall",
+                    "lValueRequested": false,
+                    "names": [],
+                    "nodeType": "FunctionCall",
+                    "src": "28224:24:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_tuple$__$",
+                      "typeString": "tuple()"
+                    }
+                  },
+                  "id": 1098,
+                  "nodeType": "ExpressionStatement",
+                  "src": "28224:24:1"
+                },
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+                  "expression": {
+                    "argumentTypes": null,
+                    "arguments": [
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+                        "argumentTypes": null,
+                        "id": 1100,
+                        "name": "to",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 1087,
+                        "src": "28287:2:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        }
+                      },
+                      {
+                        "argumentTypes": null,
+                        "id": 1101,
+                        "name": "tokenId",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 1089,
+                        "src": "28291:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      }
+                    ],
+                    "expression": {
+                      "argumentTypes": [
+                        {
+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        },
+                        {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      ],
+                      "id": 1099,
+                      "name": "_addTokenToOwnerEnumeration",
+                      "nodeType": "Identifier",
+                      "overloadedDeclarations": [],
+                      "referencedDeclaration": 1176,
+                      "src": "28259:27:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_function_internal_nonpayable$_t_address_$_t_uint256_$returns$__$",
+                        "typeString": "function (address,uint256)"
+                      }
+                    },
+                    "id": 1102,
+                    "isConstant": false,
+                    "isLValue": false,
+                    "isPure": false,
+                    "kind": "functionCall",
+                    "lValueRequested": false,
+                    "names": [],
+                    "nodeType": "FunctionCall",
+                    "src": "28259:40:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_tuple$__$",
+                      "typeString": "tuple()"
+                    }
+                  },
+                  "id": 1103,
+                  "nodeType": "ExpressionStatement",
+                  "src": "28259:40:1"
+                },
+                {
+                  "expression": {
+                    "argumentTypes": null,
+                    "arguments": [
+                      {
+                        "argumentTypes": null,
+                        "id": 1105,
+                        "name": "tokenId",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 1089,
+                        "src": "28342:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      }
+                    ],
+                    "expression": {
+                      "argumentTypes": [
+                        {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      ],
+                      "id": 1104,
+                      "name": "_addTokenToAllTokensEnumeration",
+                      "nodeType": "Identifier",
+                      "overloadedDeclarations": [],
+                      "referencedDeclaration": 1195,
+                      "src": "28310:31:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_function_internal_nonpayable$_t_uint256_$returns$__$",
+                        "typeString": "function (uint256)"
+                      }
+                    },
+                    "id": 1106,
+                    "isConstant": false,
+                    "isLValue": false,
+                    "isPure": false,
+                    "kind": "functionCall",
+                    "lValueRequested": false,
+                    "names": [],
+                    "nodeType": "FunctionCall",
+                    "src": "28310:40:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_tuple$__$",
+                      "typeString": "tuple()"
+                    }
+                  },
+                  "id": 1107,
+                  "nodeType": "ExpressionStatement",
+                  "src": "28310:40:1"
+                }
+              ]
+            },
+            "documentation": "@dev Internal function to mint a new token.\nReverts if the given token ID already exists.\n@param to address the beneficiary that will own the minted token\n@param tokenId uint256 ID of the token to be minted",
+            "id": 1109,
+            "implemented": true,
+            "kind": "function",
+            "modifiers": [],
+            "name": "_mint",
+            "nodeType": "FunctionDefinition",
+            "parameters": {
+              "id": 1090,
+              "nodeType": "ParameterList",
+              "parameters": [
+                {
+                  "constant": false,
+                  "id": 1087,
+                  "name": "to",
+                  "nodeType": "VariableDeclaration",
+                  "scope": 1109,
+                  "src": "28176:10:1",
+                  "stateVariable": false,
+                  "storageLocation": "default",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_address",
+                    "typeString": "address"
+                  },
+                  "typeName": {
+                    "id": 1086,
+                    "name": "address",
+                    "nodeType": "ElementaryTypeName",
+                    "src": "28176:7:1",
+                    "stateMutability": "nonpayable",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_address",
+                      "typeString": "address"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                },
+                {
+                  "constant": false,
+                  "id": 1089,
+                  "name": "tokenId",
+                  "nodeType": "VariableDeclaration",
+                  "scope": 1109,
+                  "src": "28188:15:1",
+                  "stateVariable": false,
+                  "storageLocation": "default",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_uint256",
+                    "typeString": "uint256"
+                  },
+                  "typeName": {
+                    "id": 1088,
+                    "name": "uint256",
+                    "nodeType": "ElementaryTypeName",
+                    "src": "28188:7:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_uint256",
+                      "typeString": "uint256"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                }
+              ],
+              "src": "28175:29:1"
+            },
+            "returnParameters": {
+              "id": 1091,
+              "nodeType": "ParameterList",
+              "parameters": [],
+              "src": "28214:0:1"
+            },
+            "scope": 1302,
+            "src": "28161:196:1",
+            "stateMutability": "nonpayable",
+            "superFunction": 768,
+            "visibility": "internal"
+          },
+          {
+            "body": {
+              "id": 1138,
+              "nodeType": "Block",
+              "src": "28688:308:1",
+              "statements": [
+                {
+                  "expression": {
+                    "argumentTypes": null,
+                    "arguments": [
+                      {
+                        "argumentTypes": null,
+                        "id": 1119,
+                        "name": "owner",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 1111,
+                        "src": "28710:5:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        }
+                      },
+                      {
+                        "argumentTypes": null,
+                        "id": 1120,
+                        "name": "tokenId",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 1113,
+                        "src": "28717:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      }
+                    ],
+                    "expression": {
+                      "argumentTypes": [
+                        {
+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        },
+                        {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      ],
+                      "expression": {
+                        "argumentTypes": null,
+                        "id": 1116,
+                        "name": "super",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 1572,
+                        "src": "28698:5:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_super$_ERC721Enumerable_$1302",
+                          "typeString": "contract super ERC721Enumerable"
+                        }
+                      },
+                      "id": 1118,
+                      "isConstant": false,
+                      "isLValue": false,
+                      "isPure": false,
+                      "lValueRequested": false,
+                      "memberName": "_burn",
+                      "nodeType": "MemberAccess",
+                      "referencedDeclaration": 811,
+                      "src": "28698:11:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_function_internal_nonpayable$_t_address_$_t_uint256_$returns$__$",
+                        "typeString": "function (address,uint256)"
+                      }
+                    },
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+                    "isConstant": false,
+                    "isLValue": false,
+                    "isPure": false,
+                    "kind": "functionCall",
+                    "lValueRequested": false,
+                    "names": [],
+                    "nodeType": "FunctionCall",
+                    "src": "28698:27:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_tuple$__$",
+                      "typeString": "tuple()"
+                    }
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+                  "id": 1122,
+                  "nodeType": "ExpressionStatement",
+                  "src": "28698:27:1"
+                },
+                {
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+                    "argumentTypes": null,
+                    "arguments": [
+                      {
+                        "argumentTypes": null,
+                        "id": 1124,
+                        "name": "owner",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 1111,
+                        "src": "28769:5:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        }
+                      },
+                      {
+                        "argumentTypes": null,
+                        "id": 1125,
+                        "name": "tokenId",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 1113,
+                        "src": "28776:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      }
+                    ],
+                    "expression": {
+                      "argumentTypes": [
+                        {
+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        },
+                        {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      ],
+                      "id": 1123,
+                      "name": "_removeTokenFromOwnerEnumeration",
+                      "nodeType": "Identifier",
+                      "overloadedDeclarations": [],
+                      "referencedDeclaration": 1252,
+                      "src": "28736:32:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_function_internal_nonpayable$_t_address_$_t_uint256_$returns$__$",
+                        "typeString": "function (address,uint256)"
+                      }
+                    },
+                    "id": 1126,
+                    "isConstant": false,
+                    "isLValue": false,
+                    "isPure": false,
+                    "kind": "functionCall",
+                    "lValueRequested": false,
+                    "names": [],
+                    "nodeType": "FunctionCall",
+                    "src": "28736:48:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_tuple$__$",
+                      "typeString": "tuple()"
+                    }
+                  },
+                  "id": 1127,
+                  "nodeType": "ExpressionStatement",
+                  "src": "28736:48:1"
+                },
+                {
+                  "expression": {
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+                    "id": 1132,
+                    "isConstant": false,
+                    "isLValue": false,
+                    "isPure": false,
+                    "lValueRequested": false,
+                    "leftHandSide": {
+                      "argumentTypes": null,
+                      "baseExpression": {
+                        "argumentTypes": null,
+                        "id": 1128,
+                        "name": "_ownedTokensIndex",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 985,
+                        "src": "28903:17:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_mapping$_t_uint256_$_t_uint256_$",
+                          "typeString": "mapping(uint256 => uint256)"
+                        }
+                      },
+                      "id": 1130,
+                      "indexExpression": {
+                        "argumentTypes": null,
+                        "id": 1129,
+                        "name": "tokenId",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 1113,
+                        "src": "28921:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      },
+                      "isConstant": false,
+                      "isLValue": true,
+                      "isPure": false,
+                      "lValueRequested": true,
+                      "nodeType": "IndexAccess",
+                      "src": "28903:26:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_uint256",
+                        "typeString": "uint256"
+                      }
+                    },
+                    "nodeType": "Assignment",
+                    "operator": "=",
+                    "rightHandSide": {
+                      "argumentTypes": null,
+                      "hexValue": "30",
+                      "id": 1131,
+                      "isConstant": false,
+                      "isLValue": false,
+                      "isPure": true,
+                      "kind": "number",
+                      "lValueRequested": false,
+                      "nodeType": "Literal",
+                      "src": "28932:1:1",
+                      "subdenomination": null,
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_rational_0_by_1",
+                        "typeString": "int_const 0"
+                      },
+                      "value": "0"
+                    },
+                    "src": "28903:30:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_uint256",
+                      "typeString": "uint256"
+                    }
+                  },
+                  "id": 1133,
+                  "nodeType": "ExpressionStatement",
+                  "src": "28903:30:1"
+                },
+                {
+                  "expression": {
+                    "argumentTypes": null,
+                    "arguments": [
+                      {
+                        "argumentTypes": null,
+                        "id": 1135,
+                        "name": "tokenId",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 1113,
+                        "src": "28981:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      }
+                    ],
+                    "expression": {
+                      "argumentTypes": [
+                        {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      ],
+                      "id": 1134,
+                      "name": "_removeTokenFromAllTokensEnumeration",
+                      "nodeType": "Identifier",
+                      "overloadedDeclarations": [],
+                      "referencedDeclaration": 1301,
+                      "src": "28944:36:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_function_internal_nonpayable$_t_uint256_$returns$__$",
+                        "typeString": "function (uint256)"
+                      }
+                    },
+                    "id": 1136,
+                    "isConstant": false,
+                    "isLValue": false,
+                    "isPure": false,
+                    "kind": "functionCall",
+                    "lValueRequested": false,
+                    "names": [],
+                    "nodeType": "FunctionCall",
+                    "src": "28944:45:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_tuple$__$",
+                      "typeString": "tuple()"
+                    }
+                  },
+                  "id": 1137,
+                  "nodeType": "ExpressionStatement",
+                  "src": "28944:45:1"
+                }
+              ]
+            },
+            "documentation": "@dev Internal function to burn a specific token.\nReverts if the token does not exist.\nDeprecated, use _burn(uint256) instead.\n@param owner owner of the token to burn\n@param tokenId uint256 ID of the token being burned",
+            "id": 1139,
+            "implemented": true,
+            "kind": "function",
+            "modifiers": [],
+            "name": "_burn",
+            "nodeType": "FunctionDefinition",
+            "parameters": {
+              "id": 1114,
+              "nodeType": "ParameterList",
+              "parameters": [
+                {
+                  "constant": false,
+                  "id": 1111,
+                  "name": "owner",
+                  "nodeType": "VariableDeclaration",
+                  "scope": 1139,
+                  "src": "28647:13:1",
+                  "stateVariable": false,
+                  "storageLocation": "default",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_address",
+                    "typeString": "address"
+                  },
+                  "typeName": {
+                    "id": 1110,
+                    "name": "address",
+                    "nodeType": "ElementaryTypeName",
+                    "src": "28647:7:1",
+                    "stateMutability": "nonpayable",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_address",
+                      "typeString": "address"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                },
+                {
+                  "constant": false,
+                  "id": 1113,
+                  "name": "tokenId",
+                  "nodeType": "VariableDeclaration",
+                  "scope": 1139,
+                  "src": "28662:15:1",
+                  "stateVariable": false,
+                  "storageLocation": "default",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_uint256",
+                    "typeString": "uint256"
+                  },
+                  "typeName": {
+                    "id": 1112,
+                    "name": "uint256",
+                    "nodeType": "ElementaryTypeName",
+                    "src": "28662:7:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_uint256",
+                      "typeString": "uint256"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                }
+              ],
+              "src": "28646:32:1"
+            },
+            "returnParameters": {
+              "id": 1115,
+              "nodeType": "ParameterList",
+              "parameters": [],
+              "src": "28688:0:1"
+            },
+            "scope": 1302,
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+                            "typeDescriptions": {
+                              "typeIdentifier": "t_address",
+                              "typeString": "address"
+                            }
+                          },
+                          "isConstant": false,
+                          "isLValue": true,
+                          "isPure": false,
+                          "lValueRequested": false,
+                          "nodeType": "IndexAccess",
+                          "src": "31060:18:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_array$_t_uint256_$dyn_storage",
+                            "typeString": "uint256[] storage ref"
+                          }
+                        },
+                        "id": 1207,
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+                        "isLValue": true,
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+                        "lValueRequested": false,
+                        "memberName": "length",
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+                        "referencedDeclaration": null,
+                        "src": "31060:25:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      },
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+                      "lValueRequested": false,
+                      "memberName": "sub",
+                      "nodeType": "MemberAccess",
+                      "referencedDeclaration": 190,
+                      "src": "31060:29:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_function_internal_pure$_t_uint256_$_t_uint256_$returns$_t_uint256_$bound_to$_t_uint256_$",
+                        "typeString": "function (uint256,uint256) pure returns (uint256)"
+                      }
+                    },
+                    "id": 1210,
+                    "isConstant": false,
+                    "isLValue": false,
+                    "isPure": false,
+                    "kind": "functionCall",
+                    "lValueRequested": false,
+                    "names": [],
+                    "nodeType": "FunctionCall",
+                    "src": "31060:32:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_uint256",
+                      "typeString": "uint256"
+                    }
+                  },
+                  "nodeType": "VariableDeclarationStatement",
+                  "src": "31035:57:1"
+                },
+                {
+                  "assignments": [
+                    1213
+                  ],
+                  "declarations": [
+                    {
+                      "constant": false,
+                      "id": 1213,
+                      "name": "tokenIndex",
+                      "nodeType": "VariableDeclaration",
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+                      "src": "31102:18:1",
+                      "stateVariable": false,
+                      "storageLocation": "default",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_uint256",
+                        "typeString": "uint256"
+                      },
+                      "typeName": {
+                        "id": 1212,
+                        "name": "uint256",
+                        "nodeType": "ElementaryTypeName",
+                        "src": "31102:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      },
+                      "value": null,
+                      "visibility": "internal"
+                    }
+                  ],
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+                      "name": "_ownedTokensIndex",
+                      "nodeType": "Identifier",
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+                      "referencedDeclaration": 985,
+                      "src": "31123:17:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_mapping$_t_uint256_$_t_uint256_$",
+                        "typeString": "mapping(uint256 => uint256)"
+                      }
+                    },
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+                      "src": "31141:7:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_uint256",
+                        "typeString": "uint256"
+                      }
+                    },
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+                    "lValueRequested": false,
+                    "nodeType": "IndexAccess",
+                    "src": "31123:26:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_uint256",
+                      "typeString": "uint256"
+                    }
+                  },
+                  "nodeType": "VariableDeclarationStatement",
+                  "src": "31102:47:1"
+                },
+                {
+                  "condition": {
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+                    "commonType": {
+                      "typeIdentifier": "t_uint256",
+                      "typeString": "uint256"
+                    },
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+                      "referencedDeclaration": 1213,
+                      "src": "31253:10:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_uint256",
+                        "typeString": "uint256"
+                      }
+                    },
+                    "nodeType": "BinaryOperation",
+                    "operator": "!=",
+                    "rightExpression": {
+                      "argumentTypes": null,
+                      "id": 1219,
+                      "name": "lastTokenIndex",
+                      "nodeType": "Identifier",
+                      "overloadedDeclarations": [],
+                      "referencedDeclaration": 1203,
+                      "src": "31267:14:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_uint256",
+                        "typeString": "uint256"
+                      }
+                    },
+                    "src": "31253:28:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_bool",
+                      "typeString": "bool"
+                    }
+                  },
+                  "falseBody": null,
+                  "id": 1244,
+                  "nodeType": "IfStatement",
+                  "src": "31249:323:1",
+                  "trueBody": {
+                    "id": 1243,
+                    "nodeType": "Block",
+                    "src": "31283:289:1",
+                    "statements": [
+                      {
+                        "assignments": [
+                          1222
+                        ],
+                        "declarations": [
+                          {
+                            "constant": false,
+                            "id": 1222,
+                            "name": "lastTokenId",
+                            "nodeType": "VariableDeclaration",
+                            "scope": 1243,
+                            "src": "31297:19:1",
+                            "stateVariable": false,
+                            "storageLocation": "default",
+                            "typeDescriptions": {
+                              "typeIdentifier": "t_uint256",
+                              "typeString": "uint256"
+                            },
+                            "typeName": {
+                              "id": 1221,
+                              "name": "uint256",
+                              "nodeType": "ElementaryTypeName",
+                              "src": "31297:7:1",
+                              "typeDescriptions": {
+                                "typeIdentifier": "t_uint256",
+                                "typeString": "uint256"
+                              }
+                            },
+                            "value": null,
+                            "visibility": "internal"
+                          }
+                        ],
+                        "id": 1228,
+                        "initialValue": {
+                          "argumentTypes": null,
+                          "baseExpression": {
+                            "argumentTypes": null,
+                            "baseExpression": {
+                              "argumentTypes": null,
+                              "id": 1223,
+                              "name": "_ownedTokens",
+                              "nodeType": "Identifier",
+                              "overloadedDeclarations": [],
+                              "referencedDeclaration": 981,
+                              "src": "31319:12:1",
+                              "typeDescriptions": {
+                                "typeIdentifier": "t_mapping$_t_address_$_t_array$_t_uint256_$dyn_storage_$",
+                                "typeString": "mapping(address => uint256[] storage ref)"
+                              }
+                            },
+                            "id": 1225,
+                            "indexExpression": {
+                              "argumentTypes": null,
+                              "id": 1224,
+                              "name": "from",
+                              "nodeType": "Identifier",
+                              "overloadedDeclarations": [],
+                              "referencedDeclaration": 1197,
+                              "src": "31332:4:1",
+                              "typeDescriptions": {
+                                "typeIdentifier": "t_address",
+                                "typeString": "address"
+                              }
+                            },
+                            "isConstant": false,
+                            "isLValue": true,
+                            "isPure": false,
+                            "lValueRequested": false,
+                            "nodeType": "IndexAccess",
+                            "src": "31319:18:1",
+                            "typeDescriptions": {
+                              "typeIdentifier": "t_array$_t_uint256_$dyn_storage",
+                              "typeString": "uint256[] storage ref"
+                            }
+                          },
+                          "id": 1227,
+                          "indexExpression": {
+                            "argumentTypes": null,
+                            "id": 1226,
+                            "name": "lastTokenIndex",
+                            "nodeType": "Identifier",
+                            "overloadedDeclarations": [],
+                            "referencedDeclaration": 1203,
+                            "src": "31338:14:1",
+                            "typeDescriptions": {
+                              "typeIdentifier": "t_uint256",
+                              "typeString": "uint256"
+                            }
+                          },
+                          "isConstant": false,
+                          "isLValue": true,
+                          "isPure": false,
+                          "lValueRequested": false,
+                          "nodeType": "IndexAccess",
+                          "src": "31319:34:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_uint256",
+                            "typeString": "uint256"
+                          }
+                        },
+                        "nodeType": "VariableDeclarationStatement",
+                        "src": "31297:56:1"
+                      },
+                      {
+                        "expression": {
+                          "argumentTypes": null,
+                          "id": 1235,
+                          "isConstant": false,
+                          "isLValue": false,
+                          "isPure": false,
+                          "lValueRequested": false,
+                          "leftHandSide": {
+                            "argumentTypes": null,
+                            "baseExpression": {
+                              "argumentTypes": null,
+                              "baseExpression": {
+                                "argumentTypes": null,
+                                "id": 1229,
+                                "name": "_ownedTokens",
+                                "nodeType": "Identifier",
+                                "overloadedDeclarations": [],
+                                "referencedDeclaration": 981,
+                                "src": "31368:12:1",
+                                "typeDescriptions": {
+                                  "typeIdentifier": "t_mapping$_t_address_$_t_array$_t_uint256_$dyn_storage_$",
+                                  "typeString": "mapping(address => uint256[] storage ref)"
+                                }
+                              },
+                              "id": 1232,
+                              "indexExpression": {
+                                "argumentTypes": null,
+                                "id": 1230,
+                                "name": "from",
+                                "nodeType": "Identifier",
+                                "overloadedDeclarations": [],
+                                "referencedDeclaration": 1197,
+                                "src": "31381:4:1",
+                                "typeDescriptions": {
+                                  "typeIdentifier": "t_address",
+                                  "typeString": "address"
+                                }
+                              },
+                              "isConstant": false,
+                              "isLValue": true,
+                              "isPure": false,
+                              "lValueRequested": false,
+                              "nodeType": "IndexAccess",
+                              "src": "31368:18:1",
+                              "typeDescriptions": {
+                                "typeIdentifier": "t_array$_t_uint256_$dyn_storage",
+                                "typeString": "uint256[] storage ref"
+                              }
+                            },
+                            "id": 1233,
+                            "indexExpression": {
+                              "argumentTypes": null,
+                              "id": 1231,
+                              "name": "tokenIndex",
+                              "nodeType": "Identifier",
+                              "overloadedDeclarations": [],
+                              "referencedDeclaration": 1213,
+                              "src": "31387:10:1",
+                              "typeDescriptions": {
+                                "typeIdentifier": "t_uint256",
+                                "typeString": "uint256"
+                              }
+                            },
+                            "isConstant": false,
+                            "isLValue": true,
+                            "isPure": false,
+                            "lValueRequested": true,
+                            "nodeType": "IndexAccess",
+                            "src": "31368:30:1",
+                            "typeDescriptions": {
+                              "typeIdentifier": "t_uint256",
+                              "typeString": "uint256"
+                            }
+                          },
+                          "nodeType": "Assignment",
+                          "operator": "=",
+                          "rightHandSide": {
+                            "argumentTypes": null,
+                            "id": 1234,
+                            "name": "lastTokenId",
+                            "nodeType": "Identifier",
+                            "overloadedDeclarations": [],
+                            "referencedDeclaration": 1222,
+                            "src": "31401:11:1",
+                            "typeDescriptions": {
+                              "typeIdentifier": "t_uint256",
+                              "typeString": "uint256"
+                            }
+                          },
+                          "src": "31368:44:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_uint256",
+                            "typeString": "uint256"
+                          }
+                        },
+                        "id": 1236,
+                        "nodeType": "ExpressionStatement",
+                        "src": "31368:44:1"
+                      },
+                      {
+                        "expression": {
+                          "argumentTypes": null,
+                          "id": 1241,
+                          "isConstant": false,
+                          "isLValue": false,
+                          "isPure": false,
+                          "lValueRequested": false,
+                          "leftHandSide": {
+                            "argumentTypes": null,
+                            "baseExpression": {
+                              "argumentTypes": null,
+                              "id": 1237,
+                              "name": "_ownedTokensIndex",
+                              "nodeType": "Identifier",
+                              "overloadedDeclarations": [],
+                              "referencedDeclaration": 985,
+                              "src": "31484:17:1",
+                              "typeDescriptions": {
+                                "typeIdentifier": "t_mapping$_t_uint256_$_t_uint256_$",
+                                "typeString": "mapping(uint256 => uint256)"
+                              }
+                            },
+                            "id": 1239,
+                            "indexExpression": {
+                              "argumentTypes": null,
+                              "id": 1238,
+                              "name": "lastTokenId",
+                              "nodeType": "Identifier",
+                              "overloadedDeclarations": [],
+                              "referencedDeclaration": 1222,
+                              "src": "31502:11:1",
+                              "typeDescriptions": {
+                                "typeIdentifier": "t_uint256",
+                                "typeString": "uint256"
+                              }
+                            },
+                            "isConstant": false,
+                            "isLValue": true,
+                            "isPure": false,
+                            "lValueRequested": true,
+                            "nodeType": "IndexAccess",
+                            "src": "31484:30:1",
+                            "typeDescriptions": {
+                              "typeIdentifier": "t_uint256",
+                              "typeString": "uint256"
+                            }
+                          },
+                          "nodeType": "Assignment",
+                          "operator": "=",
+                          "rightHandSide": {
+                            "argumentTypes": null,
+                            "id": 1240,
+                            "name": "tokenIndex",
+                            "nodeType": "Identifier",
+                            "overloadedDeclarations": [],
+                            "referencedDeclaration": 1213,
+                            "src": "31517:10:1",
+                            "typeDescriptions": {
+                              "typeIdentifier": "t_uint256",
+                              "typeString": "uint256"
+                            }
+                          },
+                          "src": "31484:43:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_uint256",
+                            "typeString": "uint256"
+                          }
+                        },
+                        "id": 1242,
+                        "nodeType": "ExpressionStatement",
+                        "src": "31484:43:1"
+                      }
+                    ]
+                  }
+                },
+                {
+                  "expression": {
+                    "argumentTypes": null,
+                    "id": 1249,
+                    "isConstant": false,
+                    "isLValue": false,
+                    "isPure": false,
+                    "lValueRequested": false,
+                    "nodeType": "UnaryOperation",
+                    "operator": "--",
+                    "prefix": false,
+                    "src": "31658:27:1",
+                    "subExpression": {
+                      "argumentTypes": null,
+                      "expression": {
+                        "argumentTypes": null,
+                        "baseExpression": {
+                          "argumentTypes": null,
+                          "id": 1245,
+                          "name": "_ownedTokens",
+                          "nodeType": "Identifier",
+                          "overloadedDeclarations": [],
+                          "referencedDeclaration": 981,
+                          "src": "31658:12:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_mapping$_t_address_$_t_array$_t_uint256_$dyn_storage_$",
+                            "typeString": "mapping(address => uint256[] storage ref)"
+                          }
+                        },
+                        "id": 1247,
+                        "indexExpression": {
+                          "argumentTypes": null,
+                          "id": 1246,
+                          "name": "from",
+                          "nodeType": "Identifier",
+                          "overloadedDeclarations": [],
+                          "referencedDeclaration": 1197,
+                          "src": "31671:4:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_address",
+                            "typeString": "address"
+                          }
+                        },
+                        "isConstant": false,
+                        "isLValue": true,
+                        "isPure": false,
+                        "lValueRequested": false,
+                        "nodeType": "IndexAccess",
+                        "src": "31658:18:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_array$_t_uint256_$dyn_storage",
+                          "typeString": "uint256[] storage ref"
+                        }
+                      },
+                      "id": 1248,
+                      "isConstant": false,
+                      "isLValue": true,
+                      "isPure": false,
+                      "lValueRequested": true,
+                      "memberName": "length",
+                      "nodeType": "MemberAccess",
+                      "referencedDeclaration": null,
+                      "src": "31658:25:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_uint256",
+                        "typeString": "uint256"
+                      }
+                    },
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_uint256",
+                      "typeString": "uint256"
+                    }
+                  },
+                  "id": 1250,
+                  "nodeType": "ExpressionStatement",
+                  "src": "31658:27:1"
+                }
+              ]
+            },
+            "documentation": "@dev Private function to remove a token from this extension's ownership-tracking data structures. Note that\nwhile the token is not assigned a new owner, the _ownedTokensIndex mapping is _not_ updated: this allows for\ngas optimizations e.g. when performing a transfer operation (avoiding double writes).\nThis has O(1) time complexity, but alters the order of the _ownedTokens array.\n@param from address representing the previous owner of the given token ID\n@param tokenId uint256 ID of the token to be removed from the tokens list of the given address",
+            "id": 1252,
+            "implemented": true,
+            "kind": "function",
+            "modifiers": [],
+            "name": "_removeTokenFromOwnerEnumeration",
+            "nodeType": "FunctionDefinition",
+            "parameters": {
+              "id": 1200,
+              "nodeType": "ParameterList",
+              "parameters": [
+                {
+                  "constant": false,
+                  "id": 1197,
+                  "name": "from",
+                  "nodeType": "VariableDeclaration",
+                  "scope": 1252,
+                  "src": "30815:12:1",
+                  "stateVariable": false,
+                  "storageLocation": "default",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_address",
+                    "typeString": "address"
+                  },
+                  "typeName": {
+                    "id": 1196,
+                    "name": "address",
+                    "nodeType": "ElementaryTypeName",
+                    "src": "30815:7:1",
+                    "stateMutability": "nonpayable",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_address",
+                      "typeString": "address"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                },
+                {
+                  "constant": false,
+                  "id": 1199,
+                  "name": "tokenId",
+                  "nodeType": "VariableDeclaration",
+                  "scope": 1252,
+                  "src": "30829:15:1",
+                  "stateVariable": false,
+                  "storageLocation": "default",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_uint256",
+                    "typeString": "uint256"
+                  },
+                  "typeName": {
+                    "id": 1198,
+                    "name": "uint256",
+                    "nodeType": "ElementaryTypeName",
+                    "src": "30829:7:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_uint256",
+                      "typeString": "uint256"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                }
+              ],
+              "src": "30814:31:1"
+            },
+            "returnParameters": {
+              "id": 1201,
+              "nodeType": "ParameterList",
+              "parameters": [],
+              "src": "30854:0:1"
+            },
+            "scope": 1302,
+            "src": "30773:1128:1",
+            "stateMutability": "nonpayable",
+            "superFunction": null,
+            "visibility": "private"
+          },
+          {
+            "body": {
+              "id": 1300,
+              "nodeType": "Block",
+              "src": "32260:993:1",
+              "statements": [
+                {
+                  "assignments": [
+                    1258
+                  ],
+                  "declarations": [
+                    {
+                      "constant": false,
+                      "id": 1258,
+                      "name": "lastTokenIndex",
+                      "nodeType": "VariableDeclaration",
+                      "scope": 1300,
+                      "src": "32438:22:1",
+                      "stateVariable": false,
+                      "storageLocation": "default",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_uint256",
+                        "typeString": "uint256"
+                      },
+                      "typeName": {
+                        "id": 1257,
+                        "name": "uint256",
+                        "nodeType": "ElementaryTypeName",
+                        "src": "32438:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      },
+                      "value": null,
+                      "visibility": "internal"
+                    }
+                  ],
+                  "id": 1264,
+                  "initialValue": {
+                    "argumentTypes": null,
+                    "arguments": [
+                      {
+                        "argumentTypes": null,
+                        "hexValue": "31",
+                        "id": 1262,
+                        "isConstant": false,
+                        "isLValue": false,
+                        "isPure": true,
+                        "kind": "number",
+                        "lValueRequested": false,
+                        "nodeType": "Literal",
+                        "src": "32485:1:1",
+                        "subdenomination": null,
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_rational_1_by_1",
+                          "typeString": "int_const 1"
+                        },
+                        "value": "1"
+                      }
+                    ],
+                    "expression": {
+                      "argumentTypes": [
+                        {
+                          "typeIdentifier": "t_rational_1_by_1",
+                          "typeString": "int_const 1"
+                        }
+                      ],
+                      "expression": {
+                        "argumentTypes": null,
+                        "expression": {
+                          "argumentTypes": null,
+                          "id": 1259,
+                          "name": "_allTokens",
+                          "nodeType": "Identifier",
+                          "overloadedDeclarations": [],
+                          "referencedDeclaration": 988,
+                          "src": "32463:10:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_array$_t_uint256_$dyn_storage",
+                            "typeString": "uint256[] storage ref"
+                          }
+                        },
+                        "id": 1260,
+                        "isConstant": false,
+                        "isLValue": true,
+                        "isPure": false,
+                        "lValueRequested": false,
+                        "memberName": "length",
+                        "nodeType": "MemberAccess",
+                        "referencedDeclaration": null,
+                        "src": "32463:17:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      },
+                      "id": 1261,
+                      "isConstant": false,
+                      "isLValue": false,
+                      "isPure": false,
+                      "lValueRequested": false,
+                      "memberName": "sub",
+                      "nodeType": "MemberAccess",
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+                        "src": "36290:5:1",
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+                        "src": "36278:5:1",
+                        "typeDescriptions": {
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+                              "nodeType": "Identifier",
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+                              "src": "36416:10:1",
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+                              "src": "36427:7:1",
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+                    "name": "address",
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+                  "visibility": "internal"
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+            "src": "36212:240:1",
+            "stateMutability": "nonpayable",
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+        "src": "33817:2637:1"
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+        "literals": [
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+          "^",
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+          ".0"
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+        "nodeType": "PragmaDirective",
+        "src": "36518:23:1"
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+            "baseName": {
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+              "id": 1450,
+              "name": "ERC721",
+              "nodeType": "UserDefinedTypeName",
+              "referencedDeclaration": 944,
+              "src": "36838:6:1",
+              "typeDescriptions": {
+                "typeIdentifier": "t_contract$_ERC721_$944",
+                "typeString": "contract ERC721"
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+            "nodeType": "InheritanceSpecifier",
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+              "nodeType": "UserDefinedTypeName",
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+              "src": "36846:16:1",
+              "typeDescriptions": {
+                "typeIdentifier": "t_contract$_ERC721Enumerable_$1302",
+                "typeString": "contract ERC721Enumerable"
+              }
+            },
+            "id": 1453,
+            "nodeType": "InheritanceSpecifier",
+            "src": "36846:16:1"
+          },
+          {
+            "arguments": null,
+            "baseName": {
+              "contractScope": null,
+              "id": 1454,
+              "name": "ERC721Metadata",
+              "nodeType": "UserDefinedTypeName",
+              "referencedDeclaration": 1448,
+              "src": "36864:14:1",
+              "typeDescriptions": {
+                "typeIdentifier": "t_contract$_ERC721Metadata_$1448",
+                "typeString": "contract ERC721Metadata"
+              }
+            },
+            "id": 1455,
+            "nodeType": "InheritanceSpecifier",
+            "src": "36864:14:1"
+          }
+        ],
+        "contractDependencies": [
+          944,
+          969,
+          23,
+          124,
+          386,
+          1302,
+          1323,
+          1448
+        ],
+        "contractKind": "contract",
+        "documentation": "@title Full ERC721 Token\nThis implementation includes all the required and some optional functionality of the ERC721 standard\nMoreover, it includes approve all functionality using operator terminology\n@dev see https://eips.ethereum.org/EIPS/eip-721",
+        "fullyImplemented": true,
+        "id": 1468,
+        "linearizedBaseContracts": [
+          1468,
+          1448,
+          1323,
+          1302,
+          969,
+          944,
+          124,
+          386,
+          23
+        ],
+        "name": "ERC721Full",
+        "nodeType": "ContractDefinition",
+        "nodes": [
+          {
+            "body": {
+              "id": 1466,
+              "nodeType": "Block",
+              "src": "36976:64:1",
+              "statements": []
+            },
+            "documentation": null,
+            "id": 1467,
+            "implemented": true,
+            "kind": "constructor",
+            "modifiers": [
+              {
+                "arguments": [
+                  {
+                    "argumentTypes": null,
+                    "id": 1462,
+                    "name": "name",
+                    "nodeType": "Identifier",
+                    "overloadedDeclarations": [],
+                    "referencedDeclaration": 1457,
+                    "src": "36962:4:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_string_memory_ptr",
+                      "typeString": "string memory"
+                    }
+                  },
+                  {
+                    "argumentTypes": null,
+                    "id": 1463,
+                    "name": "symbol",
+                    "nodeType": "Identifier",
+                    "overloadedDeclarations": [],
+                    "referencedDeclaration": 1459,
+                    "src": "36968:6:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_string_memory_ptr",
+                      "typeString": "string memory"
+                    }
+                  }
+                ],
+                "id": 1464,
+                "modifierName": {
+                  "argumentTypes": null,
+                  "id": 1461,
+                  "name": "ERC721Metadata",
+                  "nodeType": "Identifier",
+                  "overloadedDeclarations": [],
+                  "referencedDeclaration": 1448,
+                  "src": "36947:14:1",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_type$_t_contract$_ERC721Metadata_$1448_$",
+                    "typeString": "type(contract ERC721Metadata)"
+                  }
+                },
+                "nodeType": "ModifierInvocation",
+                "src": "36947:28:1"
+              }
+            ],
+            "name": "",
+            "nodeType": "FunctionDefinition",
+            "parameters": {
+              "id": 1460,
+              "nodeType": "ParameterList",
+              "parameters": [
+                {
+                  "constant": false,
+                  "id": 1457,
+                  "name": "name",
+                  "nodeType": "VariableDeclaration",
+                  "scope": 1467,
+                  "src": "36898:18:1",
+                  "stateVariable": false,
+                  "storageLocation": "memory",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_string_memory_ptr",
+                    "typeString": "string"
+                  },
+                  "typeName": {
+                    "id": 1456,
+                    "name": "string",
+                    "nodeType": "ElementaryTypeName",
+                    "src": "36898:6:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_string_storage_ptr",
+                      "typeString": "string"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                },
+                {
+                  "constant": false,
+                  "id": 1459,
+                  "name": "symbol",
+                  "nodeType": "VariableDeclaration",
+                  "scope": 1467,
+                  "src": "36918:20:1",
+                  "stateVariable": false,
+                  "storageLocation": "memory",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_string_memory_ptr",
+                    "typeString": "string"
+                  },
+                  "typeName": {
+                    "id": 1458,
+                    "name": "string",
+                    "nodeType": "ElementaryTypeName",
+                    "src": "36918:6:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_string_storage_ptr",
+                      "typeString": "string"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                }
+              ],
+              "src": "36897:42:1"
+            },
+            "returnParameters": {
+              "id": 1465,
+              "nodeType": "ParameterList",
+              "parameters": [],
+              "src": "36976:0:1"
+            },
+            "scope": 1468,
+            "src": "36885:155:1",
+            "stateMutability": "nonpayable",
+            "superFunction": null,
+            "visibility": "public"
+          }
+        ],
+        "scope": 1469,
+        "src": "36815:227:1"
+      }
+    ],
+    "src": "61:36982:1"
+  },
+  "compiler": {
+    "name": "solc",
+    "version": "0.5.0+commit.1d4f565a.Emscripten.clang"
+  },
+  "networks": {},
+  "schemaVersion": "3.0.2",
+  "updatedAt": "2019-09-05T15:01:08.689Z",
+  "devdoc": {
+    "methods": {
+      "approve(address,uint256)": {
+        "details": "Approves another address to transfer the given token ID The zero address indicates there is no approved address. There can only be one approved address per token at a given time. Can only be called by the token owner or an approved operator.",
+        "params": {
+          "to": "address to be approved for the given token ID",
+          "tokenId": "uint256 ID of the token to be approved"
+        }
+      },
+      "balanceOf(address)": {
+        "details": "Gets the balance of the specified address.",
+        "params": {
+          "owner": "address to query the balance of"
+        },
+        "return": "uint256 representing the amount owned by the passed address"
+      },
+      "constructor": {
+        "details": "Constructor function"
+      },
+      "getApproved(uint256)": {
+        "details": "Gets the approved address for a token ID, or zero if no address set Reverts if the token ID does not exist.",
+        "params": {
+          "tokenId": "uint256 ID of the token to query the approval of"
+        },
+        "return": "address currently approved for the given token ID"
+      },
+      "isApprovedForAll(address,address)": {
+        "details": "Tells whether an operator is approved by a given owner.",
+        "params": {
+          "operator": "operator address which you want to query the approval of",
+          "owner": "owner address which you want to query the approval of"
+        },
+        "return": "bool whether the given operator is approved by the given owner"
+      },
+      "name()": {
+        "details": "Gets the token name.",
+        "return": "string representing the token name"
+      },
+      "ownerOf(uint256)": {
+        "details": "Gets the owner of the specified token ID.",
+        "params": {
+          "tokenId": "uint256 ID of the token to query the owner of"
+        },
+        "return": "address currently marked as the owner of the given token ID"
+      },
+      "safeTransferFrom(address,address,uint256)": {
+        "details": "Safely transfers the ownership of a given token ID to another address If the target address is a contract, it must implement `onERC721Received`, which is called upon a safe transfer, and return the magic value `bytes4(keccak256(\"onERC721Received(address,address,uint256,bytes)\"))`; otherwise, the transfer is reverted. Requires the msg.sender to be the owner, approved, or operator",
+        "params": {
+          "from": "current owner of the token",
+          "to": "address to receive the ownership of the given token ID",
+          "tokenId": "uint256 ID of the token to be transferred"
+        }
+      },
+      "safeTransferFrom(address,address,uint256,bytes)": {
+        "details": "Safely transfers the ownership of a given token ID to another address If the target address is a contract, it must implement `onERC721Received`, which is called upon a safe transfer, and return the magic value `bytes4(keccak256(\"onERC721Received(address,address,uint256,bytes)\"))`; otherwise, the transfer is reverted. Requires the msg.sender to be the owner, approved, or operator",
+        "params": {
+          "_data": "bytes data to send along with a safe transfer check",
+          "from": "current owner of the token",
+          "to": "address to receive the ownership of the given token ID",
+          "tokenId": "uint256 ID of the token to be transferred"
+        }
+      },
+      "setApprovalForAll(address,bool)": {
+        "details": "Sets or unsets the approval of a given operator An operator is allowed to transfer all tokens of the sender on their behalf.",
+        "params": {
+          "approved": "representing the status of the approval to be set",
+          "to": "operator address to set the approval"
+        }
+      },
+      "supportsInterface(bytes4)": {
+        "details": "See `IERC165.supportsInterface`.     * Time complexity O(1), guaranteed to always use less than 30 000 gas."
+      },
+      "symbol()": {
+        "details": "Gets the token symbol.",
+        "return": "string representing the token symbol"
+      },
+      "tokenURI(uint256)": {
+        "details": "Returns an URI for a given token ID. Throws if the token ID does not exist. May return an empty string.",
+        "params": {
+          "tokenId": "uint256 ID of the token to query"
+        }
+      },
+      "transferFrom(address,address,uint256)": {
+        "details": "Transfers the ownership of a given token ID to another address. Usage of this method is discouraged, use `safeTransferFrom` whenever possible. Requires the msg.sender to be the owner, approved, or operator.",
+        "params": {
+          "from": "current owner of the token",
+          "to": "address to receive the ownership of the given token ID",
+          "tokenId": "uint256 ID of the token to be transferred"
+        }
+      }
+    }
+  },
+  "userdoc": {
+    "methods": {}
+  }
+}
\ No newline at end of file
diff --git a/src/abis/IERC165.json b/src/abis/IERC165.json
new file mode 100644
index 0000000..69611d8
--- /dev/null
+++ b/src/abis/IERC165.json
@@ -0,0 +1,37472 @@
+{
+  "contractName": "IERC165",
+  "abi": [
+    {
+      "constant": true,
+      "inputs": [
+        {
+          "name": "interfaceId",
+          "type": "bytes4"
+        }
+      ],
+      "name": "supportsInterface",
+      "outputs": [
+        {
+          "name": "",
+          "type": "bool"
+        }
+      ],
+      "payable": false,
+      "stateMutability": "view",
+      "type": "function"
+    }
+  ],
+  "bytecode": "0x",
+  "deployedBytecode": "0x",
+  "sourceMap": "",
+  "deployedSourceMap": "",
+  "source": "\n// File: @openzeppelin/contracts/introspection/IERC165.sol\n\npragma solidity ^0.5.0;\n\n/**\n * @dev Interface of the ERC165 standard, as defined in the\n * [EIP](https://eips.ethereum.org/EIPS/eip-165).\n *\n * Implementers can declare support of contract interfaces, which can then be\n * queried by others (`ERC165Checker`).\n *\n * For an implementation, see `ERC165`.\n */\ninterface IERC165 {\n    /**\n     * @dev Returns true if this contract implements the interface defined by\n     * `interfaceId`. See the corresponding\n     * [EIP section](https://eips.ethereum.org/EIPS/eip-165#how-interfaces-are-identified)\n     * to learn more about how these ids are created.\n     *\n     * This function call must use less than 30 000 gas.\n     */\n    function supportsInterface(bytes4 interfaceId) external view returns (bool);\n}\n\n// File: @openzeppelin/contracts/token/ERC721/IERC721.sol\n\npragma solidity ^0.5.0;\n\n\n/**\n * @dev Required interface of an ERC721 compliant contract.\n */\ncontract IERC721 is IERC165 {\n    event Transfer(address indexed from, address indexed to, uint256 indexed tokenId);\n    event Approval(address indexed owner, address indexed approved, uint256 indexed tokenId);\n    event ApprovalForAll(address indexed owner, address indexed operator, bool approved);\n\n    /**\n     * @dev Returns the number of NFTs in `owner`'s account.\n     */\n    function balanceOf(address owner) public view returns (uint256 balance);\n\n    /**\n     * @dev Returns the owner of the NFT specified by `tokenId`.\n     */\n    function ownerOf(uint256 tokenId) public view returns (address owner);\n\n    /**\n     * @dev Transfers a specific NFT (`tokenId`) from one account (`from`) to\n     * another (`to`).\n     *\n     * \n     *\n     * Requirements:\n     * - `from`, `to` cannot be zero.\n     * - `tokenId` must be owned by `from`.\n     * - If the caller is not `from`, it must be have been allowed to move this\n     * NFT by either `approve` or `setApproveForAll`.\n     */\n    function safeTransferFrom(address from, address to, uint256 tokenId) public;\n    /**\n     * @dev Transfers a specific NFT (`tokenId`) from one account (`from`) to\n     * another (`to`).\n     *\n     * Requirements:\n     * - If the caller is not `from`, it must be approved to move this NFT by\n     * either `approve` or `setApproveForAll`.\n     */\n    function transferFrom(address from, address to, uint256 tokenId) public;\n    function approve(address to, uint256 tokenId) public;\n    function getApproved(uint256 tokenId) public view returns (address operator);\n\n    function setApprovalForAll(address operator, bool _approved) public;\n    function isApprovedForAll(address owner, address operator) public view returns (bool);\n\n\n    function safeTransferFrom(address from, address to, uint256 tokenId, bytes memory data) public;\n}\n\n// File: @openzeppelin/contracts/token/ERC721/IERC721Receiver.sol\n\npragma solidity ^0.5.0;\n\n/**\n * @title ERC721 token receiver interface\n * @dev Interface for any contract that wants to support safeTransfers\n * from ERC721 asset contracts.\n */\ncontract IERC721Receiver {\n    /**\n     * @notice Handle the receipt of an NFT\n     * @dev The ERC721 smart contract calls this function on the recipient\n     * after a `safeTransfer`. This function MUST return the function selector,\n     * otherwise the caller will revert the transaction. The selector to be\n     * returned can be obtained as `this.onERC721Received.selector`. This\n     * function MAY throw to revert and reject the transfer.\n     * Note: the ERC721 contract address is always the message sender.\n     * @param operator The address which called `safeTransferFrom` function\n     * @param from The address which previously owned the token\n     * @param tokenId The NFT identifier which is being transferred\n     * @param data Additional data with no specified format\n     * @return bytes4 `bytes4(keccak256(\"onERC721Received(address,address,uint256,bytes)\"))`\n     */\n    function onERC721Received(address operator, address from, uint256 tokenId, bytes memory data)\n    public returns (bytes4);\n}\n\n// File: @openzeppelin/contracts/math/SafeMath.sol\n\npragma solidity ^0.5.0;\n\n/**\n * @dev Wrappers over Solidity's arithmetic operations with added overflow\n * checks.\n *\n * Arithmetic operations in Solidity wrap on overflow. This can easily result\n * in bugs, because programmers usually assume that an overflow raises an\n * error, which is the standard behavior in high level programming languages.\n * `SafeMath` restores this intuition by reverting the transaction when an\n * operation overflows.\n *\n * Using this library instead of the unchecked operations eliminates an entire\n * class of bugs, so it's recommended to use it always.\n */\nlibrary SafeMath {\n    /**\n     * @dev Returns the addition of two unsigned integers, reverting on\n     * overflow.\n     *\n     * Counterpart to Solidity's `+` operator.\n     *\n     * Requirements:\n     * - Addition cannot overflow.\n     */\n    function add(uint256 a, uint256 b) internal pure returns (uint256) {\n        uint256 c = a + b;\n        require(c >= a, \"SafeMath: addition overflow\");\n\n        return c;\n    }\n\n    /**\n     * @dev Returns the subtraction of two unsigned integers, reverting on\n     * overflow (when the result is negative).\n     *\n     * Counterpart to Solidity's `-` operator.\n     *\n     * Requirements:\n     * - Subtraction cannot overflow.\n     */\n    function sub(uint256 a, uint256 b) internal pure returns (uint256) {\n        require(b <= a, \"SafeMath: subtraction overflow\");\n        uint256 c = a - b;\n\n        return c;\n    }\n\n    /**\n     * @dev Returns the multiplication of two unsigned integers, reverting on\n     * overflow.\n     *\n     * Counterpart to Solidity's `*` operator.\n     *\n     * Requirements:\n     * - Multiplication cannot overflow.\n     */\n    function mul(uint256 a, uint256 b) internal pure returns (uint256) {\n        // Gas optimization: this is cheaper than requiring 'a' not being zero, but the\n        // benefit is lost if 'b' is also tested.\n        // See: https://github.com/OpenZeppelin/openzeppelin-contracts/pull/522\n        if (a == 0) {\n            return 0;\n        }\n\n        uint256 c = a * b;\n        require(c / a == b, \"SafeMath: multiplication overflow\");\n\n        return c;\n    }\n\n    /**\n     * @dev Returns the integer division of two unsigned integers. Reverts on\n     * division by zero. The result is rounded towards zero.\n     *\n     * Counterpart to Solidity's `/` operator. Note: this function uses a\n     * `revert` opcode (which leaves remaining gas untouched) while Solidity\n     * uses an invalid opcode to revert (consuming all remaining gas).\n     *\n     * Requirements:\n     * - The divisor cannot be zero.\n     */\n    function div(uint256 a, uint256 b) internal pure returns (uint256) {\n        // Solidity only automatically asserts when dividing by 0\n        require(b > 0, \"SafeMath: division by zero\");\n        uint256 c = a / b;\n        // assert(a == b * c + a % b); // There is no case in which this doesn't hold\n\n        return c;\n    }\n\n    /**\n     * @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo),\n     * Reverts when dividing by zero.\n     *\n     * Counterpart to Solidity's `%` operator. This function uses a `revert`\n     * opcode (which leaves remaining gas untouched) while Solidity uses an\n     * invalid opcode to revert (consuming all remaining gas).\n     *\n     * Requirements:\n     * - The divisor cannot be zero.\n     */\n    function mod(uint256 a, uint256 b) internal pure returns (uint256) {\n        require(b != 0, \"SafeMath: modulo by zero\");\n        return a % b;\n    }\n}\n\n// File: @openzeppelin/contracts/utils/Address.sol\n\npragma solidity ^0.5.0;\n\n/**\n * @dev Collection of functions related to the address type,\n */\nlibrary Address {\n    /**\n     * @dev Returns true if `account` is a contract.\n     *\n     * This test is non-exhaustive, and there may be false-negatives: during the\n     * execution of a contract's constructor, its address will be reported as\n     * not containing a contract.\n     *\n     * > It is unsafe to assume that an address for which this function returns\n     * false is an externally-owned account (EOA) and not a contract.\n     */\n    function isContract(address account) internal view returns (bool) {\n        // This method relies in extcodesize, which returns 0 for contracts in\n        // construction, since the code is only stored at the end of the\n        // constructor execution.\n\n        uint256 size;\n        // solhint-disable-next-line no-inline-assembly\n        assembly { size := extcodesize(account) }\n        return size > 0;\n    }\n}\n\n// File: @openzeppelin/contracts/drafts/Counters.sol\n\npragma solidity ^0.5.0;\n\n\n/**\n * @title Counters\n * @author Matt Condon (@shrugs)\n * @dev Provides counters that can only be incremented or decremented by one. This can be used e.g. to track the number\n * of elements in a mapping, issuing ERC721 ids, or counting request ids.\n *\n * Include with `using Counters for Counters.Counter;`\n * Since it is not possible to overflow a 256 bit integer with increments of one, `increment` can skip the SafeMath\n * overflow check, thereby saving gas. This does assume however correct usage, in that the underlying `_value` is never\n * directly accessed.\n */\nlibrary Counters {\n    using SafeMath for uint256;\n\n    struct Counter {\n        // This variable should never be directly accessed by users of the library: interactions must be restricted to\n        // the library's function. As of Solidity v0.5.2, this cannot be enforced, though there is a proposal to add\n        // this feature: see https://github.com/ethereum/solidity/issues/4637\n        uint256 _value; // default: 0\n    }\n\n    function current(Counter storage counter) internal view returns (uint256) {\n        return counter._value;\n    }\n\n    function increment(Counter storage counter) internal {\n        counter._value += 1;\n    }\n\n    function decrement(Counter storage counter) internal {\n        counter._value = counter._value.sub(1);\n    }\n}\n\n// File: @openzeppelin/contracts/introspection/ERC165.sol\n\npragma solidity ^0.5.0;\n\n\n/**\n * @dev Implementation of the `IERC165` interface.\n *\n * Contracts may inherit from this and call `_registerInterface` to declare\n * their support of an interface.\n */\ncontract ERC165 is IERC165 {\n    /*\n     * bytes4(keccak256('supportsInterface(bytes4)')) == 0x01ffc9a7\n     */\n    bytes4 private constant _INTERFACE_ID_ERC165 = 0x01ffc9a7;\n\n    /**\n     * @dev Mapping of interface ids to whether or not it's supported.\n     */\n    mapping(bytes4 => bool) private _supportedInterfaces;\n\n    constructor () internal {\n        // Derived contracts need only register support for their own interfaces,\n        // we register support for ERC165 itself here\n        _registerInterface(_INTERFACE_ID_ERC165);\n    }\n\n    /**\n     * @dev See `IERC165.supportsInterface`.\n     *\n     * Time complexity O(1), guaranteed to always use less than 30 000 gas.\n     */\n    function supportsInterface(bytes4 interfaceId) external view returns (bool) {\n        return _supportedInterfaces[interfaceId];\n    }\n\n    /**\n     * @dev Registers the contract as an implementer of the interface defined by\n     * `interfaceId`. Support of the actual ERC165 interface is automatic and\n     * registering its interface id is not required.\n     *\n     * See `IERC165.supportsInterface`.\n     *\n     * Requirements:\n     *\n     * - `interfaceId` cannot be the ERC165 invalid interface (`0xffffffff`).\n     */\n    function _registerInterface(bytes4 interfaceId) internal {\n        require(interfaceId != 0xffffffff, \"ERC165: invalid interface id\");\n        _supportedInterfaces[interfaceId] = true;\n    }\n}\n\n// File: @openzeppelin/contracts/token/ERC721/ERC721.sol\n\npragma solidity ^0.5.0;\n\n\n\n\n\n\n\n/**\n * @title ERC721 Non-Fungible Token Standard basic implementation\n * @dev see https://eips.ethereum.org/EIPS/eip-721\n */\ncontract ERC721 is ERC165, IERC721 {\n    using SafeMath for uint256;\n    using Address for address;\n    using Counters for Counters.Counter;\n\n    // Equals to `bytes4(keccak256(\"onERC721Received(address,address,uint256,bytes)\"))`\n    // which can be also obtained as `IERC721Receiver(0).onERC721Received.selector`\n    bytes4 private constant _ERC721_RECEIVED = 0x150b7a02;\n\n    // Mapping from token ID to owner\n    mapping (uint256 => address) private _tokenOwner;\n\n    // Mapping from token ID to approved address\n    mapping (uint256 => address) private _tokenApprovals;\n\n    // Mapping from owner to number of owned token\n    mapping (address => Counters.Counter) private _ownedTokensCount;\n\n    // Mapping from owner to operator approvals\n    mapping (address => mapping (address => bool)) private _operatorApprovals;\n\n    /*\n     *     bytes4(keccak256('balanceOf(address)')) == 0x70a08231\n     *     bytes4(keccak256('ownerOf(uint256)')) == 0x6352211e\n     *     bytes4(keccak256('approve(address,uint256)')) == 0x095ea7b3\n     *     bytes4(keccak256('getApproved(uint256)')) == 0x081812fc\n     *     bytes4(keccak256('setApprovalForAll(address,bool)')) == 0xa22cb465\n     *     bytes4(keccak256('isApprovedForAll(address,address)')) == 0xe985e9c\n     *     bytes4(keccak256('transferFrom(address,address,uint256)')) == 0x23b872dd\n     *     bytes4(keccak256('safeTransferFrom(address,address,uint256)')) == 0x42842e0e\n     *     bytes4(keccak256('safeTransferFrom(address,address,uint256,bytes)')) == 0xb88d4fde\n     *\n     *     => 0x70a08231 ^ 0x6352211e ^ 0x095ea7b3 ^ 0x081812fc ^\n     *        0xa22cb465 ^ 0xe985e9c ^ 0x23b872dd ^ 0x42842e0e ^ 0xb88d4fde == 0x80ac58cd\n     */\n    bytes4 private constant _INTERFACE_ID_ERC721 = 0x80ac58cd;\n\n    constructor () public {\n        // register the supported interfaces to conform to ERC721 via ERC165\n        _registerInterface(_INTERFACE_ID_ERC721);\n    }\n\n    /**\n     * @dev Gets the balance of the specified address.\n     * @param owner address to query the balance of\n     * @return uint256 representing the amount owned by the passed address\n     */\n    function balanceOf(address owner) public view returns (uint256) {\n        require(owner != address(0), \"ERC721: balance query for the zero address\");\n\n        return _ownedTokensCount[owner].current();\n    }\n\n    /**\n     * @dev Gets the owner of the specified token ID.\n     * @param tokenId uint256 ID of the token to query the owner of\n     * @return address currently marked as the owner of the given token ID\n     */\n    function ownerOf(uint256 tokenId) public view returns (address) {\n        address owner = _tokenOwner[tokenId];\n        require(owner != address(0), \"ERC721: owner query for nonexistent token\");\n\n        return owner;\n    }\n\n    /**\n     * @dev Approves another address to transfer the given token ID\n     * The zero address indicates there is no approved address.\n     * There can only be one approved address per token at a given time.\n     * Can only be called by the token owner or an approved operator.\n     * @param to address to be approved for the given token ID\n     * @param tokenId uint256 ID of the token to be approved\n     */\n    function approve(address to, uint256 tokenId) public {\n        address owner = ownerOf(tokenId);\n        require(to != owner, \"ERC721: approval to current owner\");\n\n        require(msg.sender == owner || isApprovedForAll(owner, msg.sender),\n            \"ERC721: approve caller is not owner nor approved for all\"\n        );\n\n        _tokenApprovals[tokenId] = to;\n        emit Approval(owner, to, tokenId);\n    }\n\n    /**\n     * @dev Gets the approved address for a token ID, or zero if no address set\n     * Reverts if the token ID does not exist.\n     * @param tokenId uint256 ID of the token to query the approval of\n     * @return address currently approved for the given token ID\n     */\n    function getApproved(uint256 tokenId) public view returns (address) {\n        require(_exists(tokenId), \"ERC721: approved query for nonexistent token\");\n\n        return _tokenApprovals[tokenId];\n    }\n\n    /**\n     * @dev Sets or unsets the approval of a given operator\n     * An operator is allowed to transfer all tokens of the sender on their behalf.\n     * @param to operator address to set the approval\n     * @param approved representing the status of the approval to be set\n     */\n    function setApprovalForAll(address to, bool approved) public {\n        require(to != msg.sender, \"ERC721: approve to caller\");\n\n        _operatorApprovals[msg.sender][to] = approved;\n        emit ApprovalForAll(msg.sender, to, approved);\n    }\n\n    /**\n     * @dev Tells whether an operator is approved by a given owner.\n     * @param owner owner address which you want to query the approval of\n     * @param operator operator address which you want to query the approval of\n     * @return bool whether the given operator is approved by the given owner\n     */\n    function isApprovedForAll(address owner, address operator) public view returns (bool) {\n        return _operatorApprovals[owner][operator];\n    }\n\n    /**\n     * @dev Transfers the ownership of a given token ID to another address.\n     * Usage of this method is discouraged, use `safeTransferFrom` whenever possible.\n     * Requires the msg.sender to be the owner, approved, or operator.\n     * @param from current owner of the token\n     * @param to address to receive the ownership of the given token ID\n     * @param tokenId uint256 ID of the token to be transferred\n     */\n    function transferFrom(address from, address to, uint256 tokenId) public {\n        //solhint-disable-next-line max-line-length\n        require(_isApprovedOrOwner(msg.sender, tokenId), \"ERC721: transfer caller is not owner nor approved\");\n\n        _transferFrom(from, to, tokenId);\n    }\n\n    /**\n     * @dev Safely transfers the ownership of a given token ID to another address\n     * If the target address is a contract, it must implement `onERC721Received`,\n     * which is called upon a safe transfer, and return the magic value\n     * `bytes4(keccak256(\"onERC721Received(address,address,uint256,bytes)\"))`; otherwise,\n     * the transfer is reverted.\n     * Requires the msg.sender to be the owner, approved, or operator\n     * @param from current owner of the token\n     * @param to address to receive the ownership of the given token ID\n     * @param tokenId uint256 ID of the token to be transferred\n     */\n    function safeTransferFrom(address from, address to, uint256 tokenId) public {\n        safeTransferFrom(from, to, tokenId, \"\");\n    }\n\n    /**\n     * @dev Safely transfers the ownership of a given token ID to another address\n     * If the target address is a contract, it must implement `onERC721Received`,\n     * which is called upon a safe transfer, and return the magic value\n     * `bytes4(keccak256(\"onERC721Received(address,address,uint256,bytes)\"))`; otherwise,\n     * the transfer is reverted.\n     * Requires the msg.sender to be the owner, approved, or operator\n     * @param from current owner of the token\n     * @param to address to receive the ownership of the given token ID\n     * @param tokenId uint256 ID of the token to be transferred\n     * @param _data bytes data to send along with a safe transfer check\n     */\n    function safeTransferFrom(address from, address to, uint256 tokenId, bytes memory _data) public {\n        transferFrom(from, to, tokenId);\n        require(_checkOnERC721Received(from, to, tokenId, _data), \"ERC721: transfer to non ERC721Receiver implementer\");\n    }\n\n    /**\n     * @dev Returns whether the specified token exists.\n     * @param tokenId uint256 ID of the token to query the existence of\n     * @return bool whether the token exists\n     */\n    function _exists(uint256 tokenId) internal view returns (bool) {\n        address owner = _tokenOwner[tokenId];\n        return owner != address(0);\n    }\n\n    /**\n     * @dev Returns whether the given spender can transfer a given token ID.\n     * @param spender address of the spender to query\n     * @param tokenId uint256 ID of the token to be transferred\n     * @return bool whether the msg.sender is approved for the given token ID,\n     * is an operator of the owner, or is the owner of the token\n     */\n    function _isApprovedOrOwner(address spender, uint256 tokenId) internal view returns (bool) {\n        require(_exists(tokenId), \"ERC721: operator query for nonexistent token\");\n        address owner = ownerOf(tokenId);\n        return (spender == owner || getApproved(tokenId) == spender || isApprovedForAll(owner, spender));\n    }\n\n    /**\n     * @dev Internal function to mint a new token.\n     * Reverts if the given token ID already exists.\n     * @param to The address that will own the minted token\n     * @param tokenId uint256 ID of the token to be minted\n     */\n    function _mint(address to, uint256 tokenId) internal {\n        require(to != address(0), \"ERC721: mint to the zero address\");\n        require(!_exists(tokenId), \"ERC721: token already minted\");\n\n        _tokenOwner[tokenId] = to;\n        _ownedTokensCount[to].increment();\n\n        emit Transfer(address(0), to, tokenId);\n    }\n\n    /**\n     * @dev Internal function to burn a specific token.\n     * Reverts if the token does not exist.\n     * Deprecated, use _burn(uint256) instead.\n     * @param owner owner of the token to burn\n     * @param tokenId uint256 ID of the token being burned\n     */\n    function _burn(address owner, uint256 tokenId) internal {\n        require(ownerOf(tokenId) == owner, \"ERC721: burn of token that is not own\");\n\n        _clearApproval(tokenId);\n\n        _ownedTokensCount[owner].decrement();\n        _tokenOwner[tokenId] = address(0);\n\n        emit Transfer(owner, address(0), tokenId);\n    }\n\n    /**\n     * @dev Internal function to burn a specific token.\n     * Reverts if the token does not exist.\n     * @param tokenId uint256 ID of the token being burned\n     */\n    function _burn(uint256 tokenId) internal {\n        _burn(ownerOf(tokenId), tokenId);\n    }\n\n    /**\n     * @dev Internal function to transfer ownership of a given token ID to another address.\n     * As opposed to transferFrom, this imposes no restrictions on msg.sender.\n     * @param from current owner of the token\n     * @param to address to receive the ownership of the given token ID\n     * @param tokenId uint256 ID of the token to be transferred\n     */\n    function _transferFrom(address from, address to, uint256 tokenId) internal {\n        require(ownerOf(tokenId) == from, \"ERC721: transfer of token that is not own\");\n        require(to != address(0), \"ERC721: transfer to the zero address\");\n\n        _clearApproval(tokenId);\n\n        _ownedTokensCount[from].decrement();\n        _ownedTokensCount[to].increment();\n\n        _tokenOwner[tokenId] = to;\n\n        emit Transfer(from, to, tokenId);\n    }\n\n    /**\n     * @dev Internal function to invoke `onERC721Received` on a target address.\n     * The call is not executed if the target address is not a contract.\n     *\n     * This function is deprecated.\n     * @param from address representing the previous owner of the given token ID\n     * @param to target address that will receive the tokens\n     * @param tokenId uint256 ID of the token to be transferred\n     * @param _data bytes optional data to send along with the call\n     * @return bool whether the call correctly returned the expected magic value\n     */\n    function _checkOnERC721Received(address from, address to, uint256 tokenId, bytes memory _data)\n        internal returns (bool)\n    {\n        if (!to.isContract()) {\n            return true;\n        }\n\n        bytes4 retval = IERC721Receiver(to).onERC721Received(msg.sender, from, tokenId, _data);\n        return (retval == _ERC721_RECEIVED);\n    }\n\n    /**\n     * @dev Private function to clear current approval of a given token ID.\n     * @param tokenId uint256 ID of the token to be transferred\n     */\n    function _clearApproval(uint256 tokenId) private {\n        if (_tokenApprovals[tokenId] != address(0)) {\n            _tokenApprovals[tokenId] = address(0);\n        }\n    }\n}\n\n// File: @openzeppelin/contracts/token/ERC721/IERC721Enumerable.sol\n\npragma solidity ^0.5.0;\n\n\n/**\n * @title ERC-721 Non-Fungible Token Standard, optional enumeration extension\n * @dev See https://eips.ethereum.org/EIPS/eip-721\n */\ncontract IERC721Enumerable is IERC721 {\n    function totalSupply() public view returns (uint256);\n    function tokenOfOwnerByIndex(address owner, uint256 index) public view returns (uint256 tokenId);\n\n    function tokenByIndex(uint256 index) public view returns (uint256);\n}\n\n// File: @openzeppelin/contracts/token/ERC721/ERC721Enumerable.sol\n\npragma solidity ^0.5.0;\n\n\n\n\n/**\n * @title ERC-721 Non-Fungible Token with optional enumeration extension logic\n * @dev See https://eips.ethereum.org/EIPS/eip-721\n */\ncontract ERC721Enumerable is ERC165, ERC721, IERC721Enumerable {\n    // Mapping from owner to list of owned token IDs\n    mapping(address => uint256[]) private _ownedTokens;\n\n    // Mapping from token ID to index of the owner tokens list\n    mapping(uint256 => uint256) private _ownedTokensIndex;\n\n    // Array with all token ids, used for enumeration\n    uint256[] private _allTokens;\n\n    // Mapping from token id to position in the allTokens array\n    mapping(uint256 => uint256) private _allTokensIndex;\n\n    /*\n     *     bytes4(keccak256('totalSupply()')) == 0x18160ddd\n     *     bytes4(keccak256('tokenOfOwnerByIndex(address,uint256)')) == 0x2f745c59\n     *     bytes4(keccak256('tokenByIndex(uint256)')) == 0x4f6ccce7\n     *\n     *     => 0x18160ddd ^ 0x2f745c59 ^ 0x4f6ccce7 == 0x780e9d63\n     */\n    bytes4 private constant _INTERFACE_ID_ERC721_ENUMERABLE = 0x780e9d63;\n\n    /**\n     * @dev Constructor function.\n     */\n    constructor () public {\n        // register the supported interface to conform to ERC721Enumerable via ERC165\n        _registerInterface(_INTERFACE_ID_ERC721_ENUMERABLE);\n    }\n\n    /**\n     * @dev Gets the token ID at a given index of the tokens list of the requested owner.\n     * @param owner address owning the tokens list to be accessed\n     * @param index uint256 representing the index to be accessed of the requested tokens list\n     * @return uint256 token ID at the given index of the tokens list owned by the requested address\n     */\n    function tokenOfOwnerByIndex(address owner, uint256 index) public view returns (uint256) {\n        require(index < balanceOf(owner), \"ERC721Enumerable: owner index out of bounds\");\n        return _ownedTokens[owner][index];\n    }\n\n    /**\n     * @dev Gets the total amount of tokens stored by the contract.\n     * @return uint256 representing the total amount of tokens\n     */\n    function totalSupply() public view returns (uint256) {\n        return _allTokens.length;\n    }\n\n    /**\n     * @dev Gets the token ID at a given index of all the tokens in this contract\n     * Reverts if the index is greater or equal to the total number of tokens.\n     * @param index uint256 representing the index to be accessed of the tokens list\n     * @return uint256 token ID at the given index of the tokens list\n     */\n    function tokenByIndex(uint256 index) public view returns (uint256) {\n        require(index < totalSupply(), \"ERC721Enumerable: global index out of bounds\");\n        return _allTokens[index];\n    }\n\n    /**\n     * @dev Internal function to transfer ownership of a given token ID to another address.\n     * As opposed to transferFrom, this imposes no restrictions on msg.sender.\n     * @param from current owner of the token\n     * @param to address to receive the ownership of the given token ID\n     * @param tokenId uint256 ID of the token to be transferred\n     */\n    function _transferFrom(address from, address to, uint256 tokenId) internal {\n        super._transferFrom(from, to, tokenId);\n\n        _removeTokenFromOwnerEnumeration(from, tokenId);\n\n        _addTokenToOwnerEnumeration(to, tokenId);\n    }\n\n    /**\n     * @dev Internal function to mint a new token.\n     * Reverts if the given token ID already exists.\n     * @param to address the beneficiary that will own the minted token\n     * @param tokenId uint256 ID of the token to be minted\n     */\n    function _mint(address to, uint256 tokenId) internal {\n        super._mint(to, tokenId);\n\n        _addTokenToOwnerEnumeration(to, tokenId);\n\n        _addTokenToAllTokensEnumeration(tokenId);\n    }\n\n    /**\n     * @dev Internal function to burn a specific token.\n     * Reverts if the token does not exist.\n     * Deprecated, use _burn(uint256) instead.\n     * @param owner owner of the token to burn\n     * @param tokenId uint256 ID of the token being burned\n     */\n    function _burn(address owner, uint256 tokenId) internal {\n        super._burn(owner, tokenId);\n\n        _removeTokenFromOwnerEnumeration(owner, tokenId);\n        // Since tokenId will be deleted, we can clear its slot in _ownedTokensIndex to trigger a gas refund\n        _ownedTokensIndex[tokenId] = 0;\n\n        _removeTokenFromAllTokensEnumeration(tokenId);\n    }\n\n    /**\n     * @dev Gets the list of token IDs of the requested owner.\n     * @param owner address owning the tokens\n     * @return uint256[] List of token IDs owned by the requested address\n     */\n    function _tokensOfOwner(address owner) internal view returns (uint256[] storage) {\n        return _ownedTokens[owner];\n    }\n\n    /**\n     * @dev Private function to add a token to this extension's ownership-tracking data structures.\n     * @param to address representing the new owner of the given token ID\n     * @param tokenId uint256 ID of the token to be added to the tokens list of the given address\n     */\n    function _addTokenToOwnerEnumeration(address to, uint256 tokenId) private {\n        _ownedTokensIndex[tokenId] = _ownedTokens[to].length;\n        _ownedTokens[to].push(tokenId);\n    }\n\n    /**\n     * @dev Private function to add a token to this extension's token tracking data structures.\n     * @param tokenId uint256 ID of the token to be added to the tokens list\n     */\n    function _addTokenToAllTokensEnumeration(uint256 tokenId) private {\n        _allTokensIndex[tokenId] = _allTokens.length;\n        _allTokens.push(tokenId);\n    }\n\n    /**\n     * @dev Private function to remove a token from this extension's ownership-tracking data structures. Note that\n     * while the token is not assigned a new owner, the _ownedTokensIndex mapping is _not_ updated: this allows for\n     * gas optimizations e.g. when performing a transfer operation (avoiding double writes).\n     * This has O(1) time complexity, but alters the order of the _ownedTokens array.\n     * @param from address representing the previous owner of the given token ID\n     * @param tokenId uint256 ID of the token to be removed from the tokens list of the given address\n     */\n    function _removeTokenFromOwnerEnumeration(address from, uint256 tokenId) private {\n        // To prevent a gap in from's tokens array, we store the last token in the index of the token to delete, and\n        // then delete the last slot (swap and pop).\n\n        uint256 lastTokenIndex = _ownedTokens[from].length.sub(1);\n        uint256 tokenIndex = _ownedTokensIndex[tokenId];\n\n        // When the token to delete is the last token, the swap operation is unnecessary\n        if (tokenIndex != lastTokenIndex) {\n            uint256 lastTokenId = _ownedTokens[from][lastTokenIndex];\n\n            _ownedTokens[from][tokenIndex] = lastTokenId; // Move the last token to the slot of the to-delete token\n            _ownedTokensIndex[lastTokenId] = tokenIndex; // Update the moved token's index\n        }\n\n        // This also deletes the contents at the last position of the array\n        _ownedTokens[from].length--;\n\n        // Note that _ownedTokensIndex[tokenId] hasn't been cleared: it still points to the old slot (now occupied by\n        // lastTokenId, or just over the end of the array if the token was the last one).\n    }\n\n    /**\n     * @dev Private function to remove a token from this extension's token tracking data structures.\n     * This has O(1) time complexity, but alters the order of the _allTokens array.\n     * @param tokenId uint256 ID of the token to be removed from the tokens list\n     */\n    function _removeTokenFromAllTokensEnumeration(uint256 tokenId) private {\n        // To prevent a gap in the tokens array, we store the last token in the index of the token to delete, and\n        // then delete the last slot (swap and pop).\n\n        uint256 lastTokenIndex = _allTokens.length.sub(1);\n        uint256 tokenIndex = _allTokensIndex[tokenId];\n\n        // When the token to delete is the last token, the swap operation is unnecessary. However, since this occurs so\n        // rarely (when the last minted token is burnt) that we still do the swap here to avoid the gas cost of adding\n        // an 'if' statement (like in _removeTokenFromOwnerEnumeration)\n        uint256 lastTokenId = _allTokens[lastTokenIndex];\n\n        _allTokens[tokenIndex] = lastTokenId; // Move the last token to the slot of the to-delete token\n        _allTokensIndex[lastTokenId] = tokenIndex; // Update the moved token's index\n\n        // This also deletes the contents at the last position of the array\n        _allTokens.length--;\n        _allTokensIndex[tokenId] = 0;\n    }\n}\n\n// File: @openzeppelin/contracts/token/ERC721/IERC721Metadata.sol\n\npragma solidity ^0.5.0;\n\n\n/**\n * @title ERC-721 Non-Fungible Token Standard, optional metadata extension\n * @dev See https://eips.ethereum.org/EIPS/eip-721\n */\ncontract IERC721Metadata is IERC721 {\n    function name() external view returns (string memory);\n    function symbol() external view returns (string memory);\n    function tokenURI(uint256 tokenId) external view returns (string memory);\n}\n\n// File: @openzeppelin/contracts/token/ERC721/ERC721Metadata.sol\n\npragma solidity ^0.5.0;\n\n\n\n\ncontract ERC721Metadata is ERC165, ERC721, IERC721Metadata {\n    // Token name\n    string private _name;\n\n    // Token symbol\n    string private _symbol;\n\n    // Optional mapping for token URIs\n    mapping(uint256 => string) private _tokenURIs;\n\n    /*\n     *     bytes4(keccak256('name()')) == 0x06fdde03\n     *     bytes4(keccak256('symbol()')) == 0x95d89b41\n     *     bytes4(keccak256('tokenURI(uint256)')) == 0xc87b56dd\n     *\n     *     => 0x06fdde03 ^ 0x95d89b41 ^ 0xc87b56dd == 0x5b5e139f\n     */\n    bytes4 private constant _INTERFACE_ID_ERC721_METADATA = 0x5b5e139f;\n\n    /**\n     * @dev Constructor function\n     */\n    constructor (string memory name, string memory symbol) public {\n        _name = name;\n        _symbol = symbol;\n\n        // register the supported interfaces to conform to ERC721 via ERC165\n        _registerInterface(_INTERFACE_ID_ERC721_METADATA);\n    }\n\n    /**\n     * @dev Gets the token name.\n     * @return string representing the token name\n     */\n    function name() external view returns (string memory) {\n        return _name;\n    }\n\n    /**\n     * @dev Gets the token symbol.\n     * @return string representing the token symbol\n     */\n    function symbol() external view returns (string memory) {\n        return _symbol;\n    }\n\n    /**\n     * @dev Returns an URI for a given token ID.\n     * Throws if the token ID does not exist. May return an empty string.\n     * @param tokenId uint256 ID of the token to query\n     */\n    function tokenURI(uint256 tokenId) external view returns (string memory) {\n        require(_exists(tokenId), \"ERC721Metadata: URI query for nonexistent token\");\n        return _tokenURIs[tokenId];\n    }\n\n    /**\n     * @dev Internal function to set the token URI for a given token.\n     * Reverts if the token ID does not exist.\n     * @param tokenId uint256 ID of the token to set its URI\n     * @param uri string URI to assign\n     */\n    function _setTokenURI(uint256 tokenId, string memory uri) internal {\n        require(_exists(tokenId), \"ERC721Metadata: URI set of nonexistent token\");\n        _tokenURIs[tokenId] = uri;\n    }\n\n    /**\n     * @dev Internal function to burn a specific token.\n     * Reverts if the token does not exist.\n     * Deprecated, use _burn(uint256) instead.\n     * @param owner owner of the token to burn\n     * @param tokenId uint256 ID of the token being burned by the msg.sender\n     */\n    function _burn(address owner, uint256 tokenId) internal {\n        super._burn(owner, tokenId);\n\n        // Clear metadata (if any)\n        if (bytes(_tokenURIs[tokenId]).length != 0) {\n            delete _tokenURIs[tokenId];\n        }\n    }\n}\n\n// File: @openzeppelin/contracts/token/ERC721/ERC721Full.sol\n\npragma solidity ^0.5.0;\n\n\n\n\n/**\n * @title Full ERC721 Token\n * This implementation includes all the required and some optional functionality of the ERC721 standard\n * Moreover, it includes approve all functionality using operator terminology\n * @dev see https://eips.ethereum.org/EIPS/eip-721\n */\ncontract ERC721Full is ERC721, ERC721Enumerable, ERC721Metadata {\n    constructor (string memory name, string memory symbol) public ERC721Metadata(name, symbol) {\n        // solhint-disable-previous-line no-empty-blocks\n    }\n}\n",
+  "sourcePath": "/Users/gregory/code/nft/src/contracts/ERC721Full.sol",
+  "ast": {
+    "absolutePath": "/Users/gregory/code/nft/src/contracts/ERC721Full.sol",
+    "exportedSymbols": {
+      "Address": [
+        289
+      ],
+      "Counters": [
+        336
+      ],
+      "ERC165": [
+        386
+      ],
+      "ERC721": [
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+      "ERC721Full": [
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+      "ERC721Metadata": [
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+      ],
+      "IERC165": [
+        23
+      ],
+      "IERC721": [
+        124
+      ],
+      "IERC721Enumerable": [
+        969
+      ],
+      "IERC721Metadata": [
+        1323
+      ],
+      "IERC721Receiver": [
+        139
+      ],
+      "SafeMath": [
+        271
+      ]
+    },
+    "id": 1469,
+    "nodeType": "SourceUnit",
+    "nodes": [
+      {
+        "id": 15,
+        "literals": [
+          "solidity",
+          "^",
+          "0.5",
+          ".0"
+        ],
+        "nodeType": "PragmaDirective",
+        "src": "61:23:1"
+      },
+      {
+        "baseContracts": [],
+        "contractDependencies": [],
+        "contractKind": "interface",
+        "documentation": "@dev Interface of the ERC165 standard, as defined in the\n[EIP](https://eips.ethereum.org/EIPS/eip-165).\n * Implementers can declare support of contract interfaces, which can then be\nqueried by others (`ERC165Checker`).\n * For an implementation, see `ERC165`.",
+        "fullyImplemented": false,
+        "id": 23,
+        "linearizedBaseContracts": [
+          23
+        ],
+        "name": "IERC165",
+        "nodeType": "ContractDefinition",
+        "nodes": [
+          {
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+            "documentation": "@dev Returns true if this contract implements the interface defined by\n`interfaceId`. See the corresponding\n[EIP section](https://eips.ethereum.org/EIPS/eip-165#how-interfaces-are-identified)\nto learn more about how these ids are created.\n     * This function call must use less than 30 000 gas.",
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+        "literals": [
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+                    ],
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+                          "name": "IERC721Receiver",
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+                          "src": "23593:15:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_type$_t_contract$_IERC721Receiver_$139_$",
+                            "typeString": "type(contract IERC721Receiver)"
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+                              "src": "23994:15:1",
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+                              "lValueRequested": false,
+                              "nodeType": "ElementaryTypeNameExpression",
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+                              "typeDescriptions": {
+                                "typeIdentifier": "t_type$_t_address_$",
+                                "typeString": "type(address)"
+                              },
+                              "typeName": "address"
+                            },
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+                            "isConstant": false,
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+                            "isPure": true,
+                            "kind": "typeConversion",
+                            "lValueRequested": false,
+                            "names": [],
+                            "nodeType": "FunctionCall",
+                            "src": "24021:10:1",
+                            "typeDescriptions": {
+                              "typeIdentifier": "t_address_payable",
+                              "typeString": "address payable"
+                            }
+                          },
+                          "src": "23994:37:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_address",
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+                        "nodeType": "ExpressionStatement",
+                        "src": "23994:37:1"
+                      }
+                    ]
+                  }
+                }
+              ]
+            },
+            "documentation": "@dev Private function to clear current approval of a given token ID.\n@param tokenId uint256 ID of the token to be transferred",
+            "id": 943,
+            "implemented": true,
+            "kind": "function",
+            "modifiers": [],
+            "name": "_clearApproval",
+            "nodeType": "FunctionDefinition",
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+                  "visibility": "internal"
+                }
+              ],
+              "src": "23900:17:1"
+            },
+            "returnParameters": {
+              "id": 924,
+              "nodeType": "ParameterList",
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+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      }
+                    ],
+                    "expression": {
+                      "argumentTypes": [
+                        {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      ],
+                      "id": 1134,
+                      "name": "_removeTokenFromAllTokensEnumeration",
+                      "nodeType": "Identifier",
+                      "overloadedDeclarations": [],
+                      "referencedDeclaration": 1301,
+                      "src": "28944:36:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_function_internal_nonpayable$_t_uint256_$returns$__$",
+                        "typeString": "function (uint256)"
+                      }
+                    },
+                    "id": 1136,
+                    "isConstant": false,
+                    "isLValue": false,
+                    "isPure": false,
+                    "kind": "functionCall",
+                    "lValueRequested": false,
+                    "names": [],
+                    "nodeType": "FunctionCall",
+                    "src": "28944:45:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_tuple$__$",
+                      "typeString": "tuple()"
+                    }
+                  },
+                  "id": 1137,
+                  "nodeType": "ExpressionStatement",
+                  "src": "28944:45:1"
+                }
+              ]
+            },
+            "documentation": "@dev Internal function to burn a specific token.\nReverts if the token does not exist.\nDeprecated, use _burn(uint256) instead.\n@param owner owner of the token to burn\n@param tokenId uint256 ID of the token being burned",
+            "id": 1139,
+            "implemented": true,
+            "kind": "function",
+            "modifiers": [],
+            "name": "_burn",
+            "nodeType": "FunctionDefinition",
+            "parameters": {
+              "id": 1114,
+              "nodeType": "ParameterList",
+              "parameters": [
+                {
+                  "constant": false,
+                  "id": 1111,
+                  "name": "owner",
+                  "nodeType": "VariableDeclaration",
+                  "scope": 1139,
+                  "src": "28647:13:1",
+                  "stateVariable": false,
+                  "storageLocation": "default",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_address",
+                    "typeString": "address"
+                  },
+                  "typeName": {
+                    "id": 1110,
+                    "name": "address",
+                    "nodeType": "ElementaryTypeName",
+                    "src": "28647:7:1",
+                    "stateMutability": "nonpayable",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_address",
+                      "typeString": "address"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                },
+                {
+                  "constant": false,
+                  "id": 1113,
+                  "name": "tokenId",
+                  "nodeType": "VariableDeclaration",
+                  "scope": 1139,
+                  "src": "28662:15:1",
+                  "stateVariable": false,
+                  "storageLocation": "default",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_uint256",
+                    "typeString": "uint256"
+                  },
+                  "typeName": {
+                    "id": 1112,
+                    "name": "uint256",
+                    "nodeType": "ElementaryTypeName",
+                    "src": "28662:7:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_uint256",
+                      "typeString": "uint256"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                }
+              ],
+              "src": "28646:32:1"
+            },
+            "returnParameters": {
+              "id": 1115,
+              "nodeType": "ParameterList",
+              "parameters": [],
+              "src": "28688:0:1"
+            },
+            "scope": 1302,
+            "src": "28632:364:1",
+            "stateMutability": "nonpayable",
+            "superFunction": 811,
+            "visibility": "internal"
+          },
+          {
+            "body": {
+              "id": 1151,
+              "nodeType": "Block",
+              "src": "29282:43:1",
+              "statements": [
+                {
+                  "expression": {
+                    "argumentTypes": null,
+                    "baseExpression": {
+                      "argumentTypes": null,
+                      "id": 1147,
+                      "name": "_ownedTokens",
+                      "nodeType": "Identifier",
+                      "overloadedDeclarations": [],
+                      "referencedDeclaration": 981,
+                      "src": "29299:12:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_mapping$_t_address_$_t_array$_t_uint256_$dyn_storage_$",
+                        "typeString": "mapping(address => uint256[] storage ref)"
+                      }
+                    },
+                    "id": 1149,
+                    "indexExpression": {
+                      "argumentTypes": null,
+                      "id": 1148,
+                      "name": "owner",
+                      "nodeType": "Identifier",
+                      "overloadedDeclarations": [],
+                      "referencedDeclaration": 1141,
+                      "src": "29312:5:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_address",
+                        "typeString": "address"
+                      }
+                    },
+                    "isConstant": false,
+                    "isLValue": true,
+                    "isPure": false,
+                    "lValueRequested": false,
+                    "nodeType": "IndexAccess",
+                    "src": "29299:19:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_array$_t_uint256_$dyn_storage",
+                      "typeString": "uint256[] storage ref"
+                    }
+                  },
+                  "functionReturnParameters": 1146,
+                  "id": 1150,
+                  "nodeType": "Return",
+                  "src": "29292:26:1"
+                }
+              ]
+            },
+            "documentation": "@dev Gets the list of token IDs of the requested owner.\n@param owner address owning the tokens\n@return uint256[] List of token IDs owned by the requested address",
+            "id": 1152,
+            "implemented": true,
+            "kind": "function",
+            "modifiers": [],
+            "name": "_tokensOfOwner",
+            "nodeType": "FunctionDefinition",
+            "parameters": {
+              "id": 1142,
+              "nodeType": "ParameterList",
+              "parameters": [
+                {
+                  "constant": false,
+                  "id": 1141,
+                  "name": "owner",
+                  "nodeType": "VariableDeclaration",
+                  "scope": 1152,
+                  "src": "29225:13:1",
+                  "stateVariable": false,
+                  "storageLocation": "default",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_address",
+                    "typeString": "address"
+                  },
+                  "typeName": {
+                    "id": 1140,
+                    "name": "address",
+                    "nodeType": "ElementaryTypeName",
+                    "src": "29225:7:1",
+                    "stateMutability": "nonpayable",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_address",
+                      "typeString": "address"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                }
+              ],
+              "src": "29224:15:1"
+            },
+            "returnParameters": {
+              "id": 1146,
+              "nodeType": "ParameterList",
+              "parameters": [
+                {
+                  "constant": false,
+                  "id": 1145,
+                  "name": "",
+                  "nodeType": "VariableDeclaration",
+                  "scope": 1152,
+                  "src": "29263:17:1",
+                  "stateVariable": false,
+                  "storageLocation": "storage",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_array$_t_uint256_$dyn_storage_ptr",
+                    "typeString": "uint256[]"
+                  },
+                  "typeName": {
+                    "baseType": {
+                      "id": 1143,
+                      "name": "uint256",
+                      "nodeType": "ElementaryTypeName",
+                      "src": "29263:7:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_uint256",
+                        "typeString": "uint256"
+                      }
+                    },
+                    "id": 1144,
+                    "length": null,
+                    "nodeType": "ArrayTypeName",
+                    "src": "29263:9:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_array$_t_uint256_$dyn_storage_ptr",
+                      "typeString": "uint256[]"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                }
+              ],
+              "src": "29262:19:1"
+            },
+            "scope": 1302,
+            "src": "29201:124:1",
+            "stateMutability": "view",
+            "superFunction": null,
+            "visibility": "internal"
+          },
+          {
+            "body": {
+              "id": 1175,
+              "nodeType": "Block",
+              "src": "29693:109:1",
+              "statements": [
+                {
+                  "expression": {
+                    "argumentTypes": null,
+                    "id": 1166,
+                    "isConstant": false,
+                    "isLValue": false,
+                    "isPure": false,
+                    "lValueRequested": false,
+                    "leftHandSide": {
+                      "argumentTypes": null,
+                      "baseExpression": {
+                        "argumentTypes": null,
+                        "id": 1159,
+                        "name": "_ownedTokensIndex",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 985,
+                        "src": "29703:17:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_mapping$_t_uint256_$_t_uint256_$",
+                          "typeString": "mapping(uint256 => uint256)"
+                        }
+                      },
+                      "id": 1161,
+                      "indexExpression": {
+                        "argumentTypes": null,
+                        "id": 1160,
+                        "name": "tokenId",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 1156,
+                        "src": "29721:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      },
+                      "isConstant": false,
+                      "isLValue": true,
+                      "isPure": false,
+                      "lValueRequested": true,
+                      "nodeType": "IndexAccess",
+                      "src": "29703:26:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_uint256",
+                        "typeString": "uint256"
+                      }
+                    },
+                    "nodeType": "Assignment",
+                    "operator": "=",
+                    "rightHandSide": {
+                      "argumentTypes": null,
+                      "expression": {
+                        "argumentTypes": null,
+                        "baseExpression": {
+                          "argumentTypes": null,
+                          "id": 1162,
+                          "name": "_ownedTokens",
+                          "nodeType": "Identifier",
+                          "overloadedDeclarations": [],
+                          "referencedDeclaration": 981,
+                          "src": "29732:12:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_mapping$_t_address_$_t_array$_t_uint256_$dyn_storage_$",
+                            "typeString": "mapping(address => uint256[] storage ref)"
+                          }
+                        },
+                        "id": 1164,
+                        "indexExpression": {
+                          "argumentTypes": null,
+                          "id": 1163,
+                          "name": "to",
+                          "nodeType": "Identifier",
+                          "overloadedDeclarations": [],
+                          "referencedDeclaration": 1154,
+                          "src": "29745:2:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_address",
+                            "typeString": "address"
+                          }
+                        },
+                        "isConstant": false,
+                        "isLValue": true,
+                        "isPure": false,
+                        "lValueRequested": false,
+                        "nodeType": "IndexAccess",
+                        "src": "29732:16:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_array$_t_uint256_$dyn_storage",
+                          "typeString": "uint256[] storage ref"
+                        }
+                      },
+                      "id": 1165,
+                      "isConstant": false,
+                      "isLValue": true,
+                      "isPure": false,
+                      "lValueRequested": false,
+                      "memberName": "length",
+                      "nodeType": "MemberAccess",
+                      "referencedDeclaration": null,
+                      "src": "29732:23:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_uint256",
+                        "typeString": "uint256"
+                      }
+                    },
+                    "src": "29703:52:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_uint256",
+                      "typeString": "uint256"
+                    }
+                  },
+                  "id": 1167,
+                  "nodeType": "ExpressionStatement",
+                  "src": "29703:52:1"
+                },
+                {
+                  "expression": {
+                    "argumentTypes": null,
+                    "arguments": [
+                      {
+                        "argumentTypes": null,
+                        "id": 1172,
+                        "name": "tokenId",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 1156,
+                        "src": "29787:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      }
+                    ],
+                    "expression": {
+                      "argumentTypes": [
+                        {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      ],
+                      "expression": {
+                        "argumentTypes": null,
+                        "baseExpression": {
+                          "argumentTypes": null,
+                          "id": 1168,
+                          "name": "_ownedTokens",
+                          "nodeType": "Identifier",
+                          "overloadedDeclarations": [],
+                          "referencedDeclaration": 981,
+                          "src": "29765:12:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_mapping$_t_address_$_t_array$_t_uint256_$dyn_storage_$",
+                            "typeString": "mapping(address => uint256[] storage ref)"
+                          }
+                        },
+                        "id": 1170,
+                        "indexExpression": {
+                          "argumentTypes": null,
+                          "id": 1169,
+                          "name": "to",
+                          "nodeType": "Identifier",
+                          "overloadedDeclarations": [],
+                          "referencedDeclaration": 1154,
+                          "src": "29778:2:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_address",
+                            "typeString": "address"
+                          }
+                        },
+                        "isConstant": false,
+                        "isLValue": true,
+                        "isPure": false,
+                        "lValueRequested": false,
+                        "nodeType": "IndexAccess",
+                        "src": "29765:16:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_array$_t_uint256_$dyn_storage",
+                          "typeString": "uint256[] storage ref"
+                        }
+                      },
+                      "id": 1171,
+                      "isConstant": false,
+                      "isLValue": false,
+                      "isPure": false,
+                      "lValueRequested": false,
+                      "memberName": "push",
+                      "nodeType": "MemberAccess",
+                      "referencedDeclaration": null,
+                      "src": "29765:21:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_function_arraypush_nonpayable$_t_uint256_$returns$_t_uint256_$",
+                        "typeString": "function (uint256) returns (uint256)"
+                      }
+                    },
+                    "id": 1173,
+                    "isConstant": false,
+                    "isLValue": false,
+                    "isPure": false,
+                    "kind": "functionCall",
+                    "lValueRequested": false,
+                    "names": [],
+                    "nodeType": "FunctionCall",
+                    "src": "29765:30:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_uint256",
+                      "typeString": "uint256"
+                    }
+                  },
+                  "id": 1174,
+                  "nodeType": "ExpressionStatement",
+                  "src": "29765:30:1"
+                }
+              ]
+            },
+            "documentation": "@dev Private function to add a token to this extension's ownership-tracking data structures.\n@param to address representing the new owner of the given token ID\n@param tokenId uint256 ID of the token to be added to the tokens list of the given address",
+            "id": 1176,
+            "implemented": true,
+            "kind": "function",
+            "modifiers": [],
+            "name": "_addTokenToOwnerEnumeration",
+            "nodeType": "FunctionDefinition",
+            "parameters": {
+              "id": 1157,
+              "nodeType": "ParameterList",
+              "parameters": [
+                {
+                  "constant": false,
+                  "id": 1154,
+                  "name": "to",
+                  "nodeType": "VariableDeclaration",
+                  "scope": 1176,
+                  "src": "29656:10:1",
+                  "stateVariable": false,
+                  "storageLocation": "default",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_address",
+                    "typeString": "address"
+                  },
+                  "typeName": {
+                    "id": 1153,
+                    "name": "address",
+                    "nodeType": "ElementaryTypeName",
+                    "src": "29656:7:1",
+                    "stateMutability": "nonpayable",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_address",
+                      "typeString": "address"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                },
+                {
+                  "constant": false,
+                  "id": 1156,
+                  "name": "tokenId",
+                  "nodeType": "VariableDeclaration",
+                  "scope": 1176,
+                  "src": "29668:15:1",
+                  "stateVariable": false,
+                  "storageLocation": "default",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_uint256",
+                    "typeString": "uint256"
+                  },
+                  "typeName": {
+                    "id": 1155,
+                    "name": "uint256",
+                    "nodeType": "ElementaryTypeName",
+                    "src": "29668:7:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_uint256",
+                      "typeString": "uint256"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                }
+              ],
+              "src": "29655:29:1"
+            },
+            "returnParameters": {
+              "id": 1158,
+              "nodeType": "ParameterList",
+              "parameters": [],
+              "src": "29693:0:1"
+            },
+            "scope": 1302,
+            "src": "29619:183:1",
+            "stateMutability": "nonpayable",
+            "superFunction": null,
+            "visibility": "private"
+          },
+          {
+            "body": {
+              "id": 1194,
+              "nodeType": "Block",
+              "src": "30063:95:1",
+              "statements": [
+                {
+                  "expression": {
+                    "argumentTypes": null,
+                    "id": 1186,
+                    "isConstant": false,
+                    "isLValue": false,
+                    "isPure": false,
+                    "lValueRequested": false,
+                    "leftHandSide": {
+                      "argumentTypes": null,
+                      "baseExpression": {
+                        "argumentTypes": null,
+                        "id": 1181,
+                        "name": "_allTokensIndex",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 992,
+                        "src": "30073:15:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_mapping$_t_uint256_$_t_uint256_$",
+                          "typeString": "mapping(uint256 => uint256)"
+                        }
+                      },
+                      "id": 1183,
+                      "indexExpression": {
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+                        "id": 1182,
+                        "name": "tokenId",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 1178,
+                        "src": "30089:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      },
+                      "isConstant": false,
+                      "isLValue": true,
+                      "isPure": false,
+                      "lValueRequested": true,
+                      "nodeType": "IndexAccess",
+                      "src": "30073:24:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_uint256",
+                        "typeString": "uint256"
+                      }
+                    },
+                    "nodeType": "Assignment",
+                    "operator": "=",
+                    "rightHandSide": {
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+                      "expression": {
+                        "argumentTypes": null,
+                        "id": 1184,
+                        "name": "_allTokens",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 988,
+                        "src": "30100:10:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_array$_t_uint256_$dyn_storage",
+                          "typeString": "uint256[] storage ref"
+                        }
+                      },
+                      "id": 1185,
+                      "isConstant": false,
+                      "isLValue": true,
+                      "isPure": false,
+                      "lValueRequested": false,
+                      "memberName": "length",
+                      "nodeType": "MemberAccess",
+                      "referencedDeclaration": null,
+                      "src": "30100:17:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_uint256",
+                        "typeString": "uint256"
+                      }
+                    },
+                    "src": "30073:44:1",
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+                      "typeIdentifier": "t_uint256",
+                      "typeString": "uint256"
+                    }
+                  },
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+                  "nodeType": "ExpressionStatement",
+                  "src": "30073:44:1"
+                },
+                {
+                  "expression": {
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+                    "arguments": [
+                      {
+                        "argumentTypes": null,
+                        "id": 1191,
+                        "name": "tokenId",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 1178,
+                        "src": "30143:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      }
+                    ],
+                    "expression": {
+                      "argumentTypes": [
+                        {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      ],
+                      "expression": {
+                        "argumentTypes": null,
+                        "id": 1188,
+                        "name": "_allTokens",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 988,
+                        "src": "30127:10:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_array$_t_uint256_$dyn_storage",
+                          "typeString": "uint256[] storage ref"
+                        }
+                      },
+                      "id": 1190,
+                      "isConstant": false,
+                      "isLValue": false,
+                      "isPure": false,
+                      "lValueRequested": false,
+                      "memberName": "push",
+                      "nodeType": "MemberAccess",
+                      "referencedDeclaration": null,
+                      "src": "30127:15:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_function_arraypush_nonpayable$_t_uint256_$returns$_t_uint256_$",
+                        "typeString": "function (uint256) returns (uint256)"
+                      }
+                    },
+                    "id": 1192,
+                    "isConstant": false,
+                    "isLValue": false,
+                    "isPure": false,
+                    "kind": "functionCall",
+                    "lValueRequested": false,
+                    "names": [],
+                    "nodeType": "FunctionCall",
+                    "src": "30127:24:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_uint256",
+                      "typeString": "uint256"
+                    }
+                  },
+                  "id": 1193,
+                  "nodeType": "ExpressionStatement",
+                  "src": "30127:24:1"
+                }
+              ]
+            },
+            "documentation": "@dev Private function to add a token to this extension's token tracking data structures.\n@param tokenId uint256 ID of the token to be added to the tokens list",
+            "id": 1195,
+            "implemented": true,
+            "kind": "function",
+            "modifiers": [],
+            "name": "_addTokenToAllTokensEnumeration",
+            "nodeType": "FunctionDefinition",
+            "parameters": {
+              "id": 1179,
+              "nodeType": "ParameterList",
+              "parameters": [
+                {
+                  "constant": false,
+                  "id": 1178,
+                  "name": "tokenId",
+                  "nodeType": "VariableDeclaration",
+                  "scope": 1195,
+                  "src": "30038:15:1",
+                  "stateVariable": false,
+                  "storageLocation": "default",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_uint256",
+                    "typeString": "uint256"
+                  },
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+                        "typeDescriptions": {
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+                        },
+                        "value": "1"
+                      }
+                    ],
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+                            "src": "31060:12:1",
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+                              "typeIdentifier": "t_mapping$_t_address_$_t_array$_t_uint256_$dyn_storage_$",
+                              "typeString": "mapping(address => uint256[] storage ref)"
+                            }
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+                            "src": "31073:4:1",
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+                              "typeIdentifier": "t_address",
+                              "typeString": "address"
+                            }
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+                      "src": "31060:29:1",
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+                        "typeString": "function (uint256,uint256) pure returns (uint256)"
+                      }
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+                    "src": "31060:32:1",
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+                      "typeIdentifier": "t_uint256",
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+                    }
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+                },
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+                  ],
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+                        "typeIdentifier": "t_uint256",
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+                      },
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+                        "name": "uint256",
+                        "nodeType": "ElementaryTypeName",
+                        "src": "31102:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
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+                        "typeIdentifier": "t_mapping$_t_uint256_$_t_uint256_$",
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+                      }
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+                        "typeString": "uint256"
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+                    "typeDescriptions": {
+                      "typeIdentifier": "t_uint256",
+                      "typeString": "uint256"
+                    }
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+                },
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+                      "src": "31253:10:1",
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+                        "typeIdentifier": "t_uint256",
+                        "typeString": "uint256"
+                      }
+                    },
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+                      "name": "lastTokenIndex",
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+                      "src": "31267:14:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_uint256",
+                        "typeString": "uint256"
+                      }
+                    },
+                    "src": "31253:28:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_bool",
+                      "typeString": "bool"
+                    }
+                  },
+                  "falseBody": null,
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+                    "statements": [
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+                        "assignments": [
+                          1222
+                        ],
+                        "declarations": [
+                          {
+                            "constant": false,
+                            "id": 1222,
+                            "name": "lastTokenId",
+                            "nodeType": "VariableDeclaration",
+                            "scope": 1243,
+                            "src": "31297:19:1",
+                            "stateVariable": false,
+                            "storageLocation": "default",
+                            "typeDescriptions": {
+                              "typeIdentifier": "t_uint256",
+                              "typeString": "uint256"
+                            },
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+                              "name": "uint256",
+                              "nodeType": "ElementaryTypeName",
+                              "src": "31297:7:1",
+                              "typeDescriptions": {
+                                "typeIdentifier": "t_uint256",
+                                "typeString": "uint256"
+                              }
+                            },
+                            "value": null,
+                            "visibility": "internal"
+                          }
+                        ],
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+                          "baseExpression": {
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+                              "id": 1223,
+                              "name": "_ownedTokens",
+                              "nodeType": "Identifier",
+                              "overloadedDeclarations": [],
+                              "referencedDeclaration": 981,
+                              "src": "31319:12:1",
+                              "typeDescriptions": {
+                                "typeIdentifier": "t_mapping$_t_address_$_t_array$_t_uint256_$dyn_storage_$",
+                                "typeString": "mapping(address => uint256[] storage ref)"
+                              }
+                            },
+                            "id": 1225,
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+                              "name": "from",
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+                              "referencedDeclaration": 1197,
+                              "src": "31332:4:1",
+                              "typeDescriptions": {
+                                "typeIdentifier": "t_address",
+                                "typeString": "address"
+                              }
+                            },
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+                            "nodeType": "IndexAccess",
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+                              "typeIdentifier": "t_array$_t_uint256_$dyn_storage",
+                              "typeString": "uint256[] storage ref"
+                            }
+                          },
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+                            "name": "lastTokenIndex",
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+                            "src": "31338:14:1",
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+                              "typeIdentifier": "t_uint256",
+                              "typeString": "uint256"
+                            }
+                          },
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+                            "typeIdentifier": "t_uint256",
+                            "typeString": "uint256"
+                          }
+                        },
+                        "nodeType": "VariableDeclarationStatement",
+                        "src": "31297:56:1"
+                      },
+                      {
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+                              "baseExpression": {
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+                                "name": "_ownedTokens",
+                                "nodeType": "Identifier",
+                                "overloadedDeclarations": [],
+                                "referencedDeclaration": 981,
+                                "src": "31368:12:1",
+                                "typeDescriptions": {
+                                  "typeIdentifier": "t_mapping$_t_address_$_t_array$_t_uint256_$dyn_storage_$",
+                                  "typeString": "mapping(address => uint256[] storage ref)"
+                                }
+                              },
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+                                "argumentTypes": null,
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+                                "name": "from",
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+                                "referencedDeclaration": 1197,
+                                "src": "31381:4:1",
+                                "typeDescriptions": {
+                                  "typeIdentifier": "t_address",
+                                  "typeString": "address"
+                                }
+                              },
+                              "isConstant": false,
+                              "isLValue": true,
+                              "isPure": false,
+                              "lValueRequested": false,
+                              "nodeType": "IndexAccess",
+                              "src": "31368:18:1",
+                              "typeDescriptions": {
+                                "typeIdentifier": "t_array$_t_uint256_$dyn_storage",
+                                "typeString": "uint256[] storage ref"
+                              }
+                            },
+                            "id": 1233,
+                            "indexExpression": {
+                              "argumentTypes": null,
+                              "id": 1231,
+                              "name": "tokenIndex",
+                              "nodeType": "Identifier",
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+                              "referencedDeclaration": 1213,
+                              "src": "31387:10:1",
+                              "typeDescriptions": {
+                                "typeIdentifier": "t_uint256",
+                                "typeString": "uint256"
+                              }
+                            },
+                            "isConstant": false,
+                            "isLValue": true,
+                            "isPure": false,
+                            "lValueRequested": true,
+                            "nodeType": "IndexAccess",
+                            "src": "31368:30:1",
+                            "typeDescriptions": {
+                              "typeIdentifier": "t_uint256",
+                              "typeString": "uint256"
+                            }
+                          },
+                          "nodeType": "Assignment",
+                          "operator": "=",
+                          "rightHandSide": {
+                            "argumentTypes": null,
+                            "id": 1234,
+                            "name": "lastTokenId",
+                            "nodeType": "Identifier",
+                            "overloadedDeclarations": [],
+                            "referencedDeclaration": 1222,
+                            "src": "31401:11:1",
+                            "typeDescriptions": {
+                              "typeIdentifier": "t_uint256",
+                              "typeString": "uint256"
+                            }
+                          },
+                          "src": "31368:44:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_uint256",
+                            "typeString": "uint256"
+                          }
+                        },
+                        "id": 1236,
+                        "nodeType": "ExpressionStatement",
+                        "src": "31368:44:1"
+                      },
+                      {
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+                          "id": 1241,
+                          "isConstant": false,
+                          "isLValue": false,
+                          "isPure": false,
+                          "lValueRequested": false,
+                          "leftHandSide": {
+                            "argumentTypes": null,
+                            "baseExpression": {
+                              "argumentTypes": null,
+                              "id": 1237,
+                              "name": "_ownedTokensIndex",
+                              "nodeType": "Identifier",
+                              "overloadedDeclarations": [],
+                              "referencedDeclaration": 985,
+                              "src": "31484:17:1",
+                              "typeDescriptions": {
+                                "typeIdentifier": "t_mapping$_t_uint256_$_t_uint256_$",
+                                "typeString": "mapping(uint256 => uint256)"
+                              }
+                            },
+                            "id": 1239,
+                            "indexExpression": {
+                              "argumentTypes": null,
+                              "id": 1238,
+                              "name": "lastTokenId",
+                              "nodeType": "Identifier",
+                              "overloadedDeclarations": [],
+                              "referencedDeclaration": 1222,
+                              "src": "31502:11:1",
+                              "typeDescriptions": {
+                                "typeIdentifier": "t_uint256",
+                                "typeString": "uint256"
+                              }
+                            },
+                            "isConstant": false,
+                            "isLValue": true,
+                            "isPure": false,
+                            "lValueRequested": true,
+                            "nodeType": "IndexAccess",
+                            "src": "31484:30:1",
+                            "typeDescriptions": {
+                              "typeIdentifier": "t_uint256",
+                              "typeString": "uint256"
+                            }
+                          },
+                          "nodeType": "Assignment",
+                          "operator": "=",
+                          "rightHandSide": {
+                            "argumentTypes": null,
+                            "id": 1240,
+                            "name": "tokenIndex",
+                            "nodeType": "Identifier",
+                            "overloadedDeclarations": [],
+                            "referencedDeclaration": 1213,
+                            "src": "31517:10:1",
+                            "typeDescriptions": {
+                              "typeIdentifier": "t_uint256",
+                              "typeString": "uint256"
+                            }
+                          },
+                          "src": "31484:43:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_uint256",
+                            "typeString": "uint256"
+                          }
+                        },
+                        "id": 1242,
+                        "nodeType": "ExpressionStatement",
+                        "src": "31484:43:1"
+                      }
+                    ]
+                  }
+                },
+                {
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+                    "id": 1249,
+                    "isConstant": false,
+                    "isLValue": false,
+                    "isPure": false,
+                    "lValueRequested": false,
+                    "nodeType": "UnaryOperation",
+                    "operator": "--",
+                    "prefix": false,
+                    "src": "31658:27:1",
+                    "subExpression": {
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+                      "expression": {
+                        "argumentTypes": null,
+                        "baseExpression": {
+                          "argumentTypes": null,
+                          "id": 1245,
+                          "name": "_ownedTokens",
+                          "nodeType": "Identifier",
+                          "overloadedDeclarations": [],
+                          "referencedDeclaration": 981,
+                          "src": "31658:12:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_mapping$_t_address_$_t_array$_t_uint256_$dyn_storage_$",
+                            "typeString": "mapping(address => uint256[] storage ref)"
+                          }
+                        },
+                        "id": 1247,
+                        "indexExpression": {
+                          "argumentTypes": null,
+                          "id": 1246,
+                          "name": "from",
+                          "nodeType": "Identifier",
+                          "overloadedDeclarations": [],
+                          "referencedDeclaration": 1197,
+                          "src": "31671:4:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_address",
+                            "typeString": "address"
+                          }
+                        },
+                        "isConstant": false,
+                        "isLValue": true,
+                        "isPure": false,
+                        "lValueRequested": false,
+                        "nodeType": "IndexAccess",
+                        "src": "31658:18:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_array$_t_uint256_$dyn_storage",
+                          "typeString": "uint256[] storage ref"
+                        }
+                      },
+                      "id": 1248,
+                      "isConstant": false,
+                      "isLValue": true,
+                      "isPure": false,
+                      "lValueRequested": true,
+                      "memberName": "length",
+                      "nodeType": "MemberAccess",
+                      "referencedDeclaration": null,
+                      "src": "31658:25:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_uint256",
+                        "typeString": "uint256"
+                      }
+                    },
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_uint256",
+                      "typeString": "uint256"
+                    }
+                  },
+                  "id": 1250,
+                  "nodeType": "ExpressionStatement",
+                  "src": "31658:27:1"
+                }
+              ]
+            },
+            "documentation": "@dev Private function to remove a token from this extension's ownership-tracking data structures. Note that\nwhile the token is not assigned a new owner, the _ownedTokensIndex mapping is _not_ updated: this allows for\ngas optimizations e.g. when performing a transfer operation (avoiding double writes).\nThis has O(1) time complexity, but alters the order of the _ownedTokens array.\n@param from address representing the previous owner of the given token ID\n@param tokenId uint256 ID of the token to be removed from the tokens list of the given address",
+            "id": 1252,
+            "implemented": true,
+            "kind": "function",
+            "modifiers": [],
+            "name": "_removeTokenFromOwnerEnumeration",
+            "nodeType": "FunctionDefinition",
+            "parameters": {
+              "id": 1200,
+              "nodeType": "ParameterList",
+              "parameters": [
+                {
+                  "constant": false,
+                  "id": 1197,
+                  "name": "from",
+                  "nodeType": "VariableDeclaration",
+                  "scope": 1252,
+                  "src": "30815:12:1",
+                  "stateVariable": false,
+                  "storageLocation": "default",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_address",
+                    "typeString": "address"
+                  },
+                  "typeName": {
+                    "id": 1196,
+                    "name": "address",
+                    "nodeType": "ElementaryTypeName",
+                    "src": "30815:7:1",
+                    "stateMutability": "nonpayable",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_address",
+                      "typeString": "address"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                },
+                {
+                  "constant": false,
+                  "id": 1199,
+                  "name": "tokenId",
+                  "nodeType": "VariableDeclaration",
+                  "scope": 1252,
+                  "src": "30829:15:1",
+                  "stateVariable": false,
+                  "storageLocation": "default",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_uint256",
+                    "typeString": "uint256"
+                  },
+                  "typeName": {
+                    "id": 1198,
+                    "name": "uint256",
+                    "nodeType": "ElementaryTypeName",
+                    "src": "30829:7:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_uint256",
+                      "typeString": "uint256"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
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+                        "src": "36290:5:1",
+                        "typeDescriptions": {
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+                          "typeString": "address"
+                        }
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+                        "name": "tokenId",
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+                        "src": "36297:7:1",
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+                        "src": "36278:5:1",
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+                          "isConstant": false,
+                          "isLValue": false,
+                          "isPure": false,
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+                          "nodeType": "UnaryOperation",
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+                          "prefix": true,
+                          "src": "36409:26:1",
+                          "subExpression": {
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+                            "baseExpression": {
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+                              "name": "_tokenURIs",
+                              "nodeType": "Identifier",
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+                              "referencedDeclaration": 1338,
+                              "src": "36416:10:1",
+                              "typeDescriptions": {
+                                "typeIdentifier": "t_mapping$_t_uint256_$_t_string_storage_$",
+                                "typeString": "mapping(uint256 => string storage ref)"
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+                              "src": "36427:7:1",
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+                            "typeString": "tuple()"
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+                    ]
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+              ]
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+                            "src": "21080:1:1",
+                            "subdenomination": null,
+                            "typeDescriptions": {
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+                              "typeString": "int_const 0"
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+                          }
+                        ],
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+                          "argumentTypes": [
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+                              "typeString": "int_const 0"
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+                          "isLValue": false,
+                          "isPure": true,
+                          "lValueRequested": false,
+                          "nodeType": "ElementaryTypeNameExpression",
+                          "src": "21072:7:1",
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+                            "typeString": "type(address)"
+                          },
+                          "typeName": "address"
+                        },
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+                        "isLValue": false,
+                        "isPure": true,
+                        "kind": "typeConversion",
+                        "lValueRequested": false,
+                        "names": [],
+                        "nodeType": "FunctionCall",
+                        "src": "21072:10:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_address_payable",
+                          "typeString": "address payable"
+                        }
+                      },
+                      {
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+                        "id": 763,
+                        "name": "to",
+                        "nodeType": "Identifier",
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+                        "src": "21084:2:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        }
+                      },
+                      {
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+                        "id": 764,
+                        "name": "tokenId",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 727,
+                        "src": "21088:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      }
+                    ],
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+                      "argumentTypes": [
+                        {
+                          "typeIdentifier": "t_address_payable",
+                          "typeString": "address payable"
+                        },
+                        {
+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        },
+                        {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      ],
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+                      "name": "Transfer",
+                      "nodeType": "Identifier",
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+                      "src": "21063:8:1",
+                      "typeDescriptions": {
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+                  "nodeType": "EmitStatement",
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+                }
+              ]
+            },
+            "documentation": "@dev Internal function to mint a new token.\nReverts if the given token ID already exists.\n@param to The address that will own the minted token\n@param tokenId uint256 ID of the token to be minted",
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+            "implemented": true,
+            "kind": "function",
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+            "name": "_mint",
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+                  "scope": 768,
+                  "src": "20791:10:1",
+                  "stateVariable": false,
+                  "storageLocation": "default",
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+                    "typeIdentifier": "t_address",
+                    "typeString": "address"
+                  },
+                  "typeName": {
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+                    "name": "address",
+                    "nodeType": "ElementaryTypeName",
+                    "src": "20791:7:1",
+                    "stateMutability": "nonpayable",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_address",
+                      "typeString": "address"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                },
+                {
+                  "constant": false,
+                  "id": 727,
+                  "name": "tokenId",
+                  "nodeType": "VariableDeclaration",
+                  "scope": 768,
+                  "src": "20803:15:1",
+                  "stateVariable": false,
+                  "storageLocation": "default",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_uint256",
+                    "typeString": "uint256"
+                  },
+                  "typeName": {
+                    "id": 726,
+                    "name": "uint256",
+                    "nodeType": "ElementaryTypeName",
+                    "src": "20803:7:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_uint256",
+                      "typeString": "uint256"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                }
+              ],
+              "src": "20790:29:1"
+            },
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+              "id": 729,
+              "nodeType": "ParameterList",
+              "parameters": [],
+              "src": "20829:0:1"
+            },
+            "scope": 944,
+            "src": "20776:327:1",
+            "stateMutability": "nonpayable",
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+            "visibility": "internal"
+          },
+          {
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+              "nodeType": "Block",
+              "src": "21434:268:1",
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+                      {
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+                        "commonType": {
+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
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+                        "isConstant": false,
+                        "isLValue": false,
+                        "isPure": false,
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+                          "argumentTypes": null,
+                          "arguments": [
+                            {
+                              "argumentTypes": null,
+                              "id": 777,
+                              "name": "tokenId",
+                              "nodeType": "Identifier",
+                              "overloadedDeclarations": [],
+                              "referencedDeclaration": 772,
+                              "src": "21460:7:1",
+                              "typeDescriptions": {
+                                "typeIdentifier": "t_uint256",
+                                "typeString": "uint256"
+                              }
+                            }
+                          ],
+                          "expression": {
+                            "argumentTypes": [
+                              {
+                                "typeIdentifier": "t_uint256",
+                                "typeString": "uint256"
+                              }
+                            ],
+                            "id": 776,
+                            "name": "ownerOf",
+                            "nodeType": "Identifier",
+                            "overloadedDeclarations": [
+                              480
+                            ],
+                            "referencedDeclaration": 480,
+                            "src": "21452:7:1",
+                            "typeDescriptions": {
+                              "typeIdentifier": "t_function_internal_view$_t_uint256_$returns$_t_address_$",
+                              "typeString": "function (uint256) view returns (address)"
+                            }
+                          },
+                          "id": 778,
+                          "isConstant": false,
+                          "isLValue": false,
+                          "isPure": false,
+                          "kind": "functionCall",
+                          "lValueRequested": false,
+                          "names": [],
+                          "nodeType": "FunctionCall",
+                          "src": "21452:16:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_address",
+                            "typeString": "address"
+                          }
+                        },
+                        "nodeType": "BinaryOperation",
+                        "operator": "==",
+                        "rightExpression": {
+                          "argumentTypes": null,
+                          "id": 779,
+                          "name": "owner",
+                          "nodeType": "Identifier",
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+                          "src": "21472:5:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_address",
+                            "typeString": "address"
+                          }
+                        },
+                        "src": "21452:25:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_bool",
+                          "typeString": "bool"
+                        }
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+                        "kind": "string",
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+                        "nodeType": "Literal",
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+                        "typeDescriptions": {
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+                          "typeString": "literal_string \"ERC721: burn of token that is not own\""
+                        },
+                        "value": "ERC721: burn of token that is not own"
+                      }
+                    ],
+                    "expression": {
+                      "argumentTypes": [
+                        {
+                          "typeIdentifier": "t_bool",
+                          "typeString": "bool"
+                        },
+                        {
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+                          "typeString": "literal_string \"ERC721: burn of token that is not own\""
+                        }
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+                      "name": "require",
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+                      ],
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+                      "src": "21444:7:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_function_require_pure$_t_bool_$_t_string_memory_ptr_$returns$__$",
+                        "typeString": "function (bool,string memory) pure"
+                      }
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+                        "id": 785,
+                        "name": "tokenId",
+                        "nodeType": "Identifier",
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+                        "referencedDeclaration": 772,
+                        "src": "21545:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      }
+                    ],
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+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
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+                      "src": "21530:14:1",
+                      "typeDescriptions": {
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+                        "typeString": "function (uint256)"
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+                        "baseExpression": {
+                          "argumentTypes": null,
+                          "id": 788,
+                          "name": "_ownedTokensCount",
+                          "nodeType": "Identifier",
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+                          "referencedDeclaration": 415,
+                          "src": "21564:17:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_mapping$_t_address_$_t_struct$_Counter_$296_storage_$",
+                            "typeString": "mapping(address => struct Counters.Counter storage ref)"
+                          }
+                        },
+                        "id": 790,
+                        "indexExpression": {
+                          "argumentTypes": null,
+                          "id": 789,
+                          "name": "owner",
+                          "nodeType": "Identifier",
+                          "overloadedDeclarations": [],
+                          "referencedDeclaration": 770,
+                          "src": "21582:5:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_address",
+                            "typeString": "address"
+                          }
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+                        "isLValue": true,
+                        "isPure": false,
+                        "lValueRequested": false,
+                        "nodeType": "IndexAccess",
+                        "src": "21564:24:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_struct$_Counter_$296_storage",
+                          "typeString": "struct Counters.Counter storage ref"
+                        }
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+                      "isConstant": false,
+                      "isLValue": true,
+                      "isPure": false,
+                      "lValueRequested": false,
+                      "memberName": "decrement",
+                      "nodeType": "MemberAccess",
+                      "referencedDeclaration": 335,
+                      "src": "21564:34:1",
+                      "typeDescriptions": {
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+                        "typeString": "function (struct Counters.Counter storage pointer)"
+                      }
+                    },
+                    "id": 792,
+                    "isConstant": false,
+                    "isLValue": false,
+                    "isPure": false,
+                    "kind": "functionCall",
+                    "lValueRequested": false,
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+                    "nodeType": "FunctionCall",
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+                    "typeDescriptions": {
+                      "typeIdentifier": "t_tuple$__$",
+                      "typeString": "tuple()"
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+                  "nodeType": "ExpressionStatement",
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+                    "isConstant": false,
+                    "isLValue": false,
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+                      "baseExpression": {
+                        "argumentTypes": null,
+                        "id": 794,
+                        "name": "_tokenOwner",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 407,
+                        "src": "21610:11:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_mapping$_t_uint256_$_t_address_$",
+                          "typeString": "mapping(uint256 => address)"
+                        }
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+                        "argumentTypes": null,
+                        "id": 795,
+                        "name": "tokenId",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 772,
+                        "src": "21622:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
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+                      "nodeType": "IndexAccess",
+                      "src": "21610:20:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_address",
+                        "typeString": "address"
+                      }
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+                    "rightHandSide": {
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+                      "arguments": [
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+                          "argumentTypes": null,
+                          "hexValue": "30",
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+                          "nodeType": "Literal",
+                          "src": "21641:1:1",
+                          "subdenomination": null,
+                          "typeDescriptions": {
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+                            "typeString": "int_const 0"
+                          },
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+                        }
+                      ],
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+                            "typeString": "int_const 0"
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+                        "isPure": true,
+                        "lValueRequested": false,
+                        "nodeType": "ElementaryTypeNameExpression",
+                        "src": "21633:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_type$_t_address_$",
+                          "typeString": "type(address)"
+                        },
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+                      "nodeType": "FunctionCall",
+                      "src": "21633:10:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_address_payable",
+                        "typeString": "address payable"
+                      }
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+                      "typeIdentifier": "t_address",
+                      "typeString": "address"
+                    }
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+                  "src": "21610:33:1"
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+                    "arguments": [
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+                        "id": 803,
+                        "name": "owner",
+                        "nodeType": "Identifier",
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+                        "referencedDeclaration": 770,
+                        "src": "21668:5:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        }
+                      },
+                      {
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+                        "arguments": [
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+                            "argumentTypes": null,
+                            "hexValue": "30",
+                            "id": 805,
+                            "isConstant": false,
+                            "isLValue": false,
+                            "isPure": true,
+                            "kind": "number",
+                            "lValueRequested": false,
+                            "nodeType": "Literal",
+                            "src": "21683:1:1",
+                            "subdenomination": null,
+                            "typeDescriptions": {
+                              "typeIdentifier": "t_rational_0_by_1",
+                              "typeString": "int_const 0"
+                            },
+                            "value": "0"
+                          }
+                        ],
+                        "expression": {
+                          "argumentTypes": [
+                            {
+                              "typeIdentifier": "t_rational_0_by_1",
+                              "typeString": "int_const 0"
+                            }
+                          ],
+                          "id": 804,
+                          "isConstant": false,
+                          "isLValue": false,
+                          "isPure": true,
+                          "lValueRequested": false,
+                          "nodeType": "ElementaryTypeNameExpression",
+                          "src": "21675:7:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_type$_t_address_$",
+                            "typeString": "type(address)"
+                          },
+                          "typeName": "address"
+                        },
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+                        "isConstant": false,
+                        "isLValue": false,
+                        "isPure": true,
+                        "kind": "typeConversion",
+                        "lValueRequested": false,
+                        "names": [],
+                        "nodeType": "FunctionCall",
+                        "src": "21675:10:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_address_payable",
+                          "typeString": "address payable"
+                        }
+                      },
+                      {
+                        "argumentTypes": null,
+                        "id": 807,
+                        "name": "tokenId",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 772,
+                        "src": "21687:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      }
+                    ],
+                    "expression": {
+                      "argumentTypes": [
+                        {
+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        },
+                        {
+                          "typeIdentifier": "t_address_payable",
+                          "typeString": "address payable"
+                        },
+                        {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      ],
+                      "id": 802,
+                      "name": "Transfer",
+                      "nodeType": "Identifier",
+                      "overloadedDeclarations": [],
+                      "referencedDeclaration": 34,
+                      "src": "21659:8:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_function_event_nonpayable$_t_address_$_t_address_$_t_uint256_$returns$__$",
+                        "typeString": "function (address,address,uint256)"
+                      }
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+                    "isLValue": false,
+                    "isPure": false,
+                    "kind": "functionCall",
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+                    "nodeType": "FunctionCall",
+                    "src": "21659:36:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_tuple$__$",
+                      "typeString": "tuple()"
+                    }
+                  },
+                  "id": 809,
+                  "nodeType": "EmitStatement",
+                  "src": "21654:41:1"
+                }
+              ]
+            },
+            "documentation": "@dev Internal function to burn a specific token.\nReverts if the token does not exist.\nDeprecated, use _burn(uint256) instead.\n@param owner owner of the token to burn\n@param tokenId uint256 ID of the token being burned",
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+            "implemented": true,
+            "kind": "function",
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+            "name": "_burn",
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+                        "typeString": "address"
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+                        "src": "22770:4:1",
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+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        }
+                      },
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+                        "name": "to",
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+                        "src": "22776:2:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        }
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+                        "src": "22780:7:1",
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+                          "typeString": "uint256"
+                        }
+                      }
+                    ],
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+                      "argumentTypes": [
+                        {
+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        },
+                        {
+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        },
+                        {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      ],
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+                      "name": "Transfer",
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+                      "src": "22761:8:1",
+                      "typeDescriptions": {
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+                      }
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+                  "nodeType": "EmitStatement",
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+                }
+              ]
+            },
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+            "name": "_transferFrom",
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+                    "typeString": "address"
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+                    "name": "address",
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+                    "src": "22371:7:1",
+                    "stateMutability": "nonpayable",
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+                      "typeIdentifier": "t_address",
+                      "typeString": "address"
+                    }
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+                  "visibility": "internal"
+                },
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+                  "id": 828,
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+                  "storageLocation": "default",
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+                    "typeString": "address"
+                  },
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+                    "name": "address",
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+                    "src": "22385:7:1",
+                    "stateMutability": "nonpayable",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_address",
+                      "typeString": "address"
+                    }
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+                    "typeString": "uint256"
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+                    "name": "uint256",
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+                      "typeString": "uint256"
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+            "visibility": "internal"
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+              "nodeType": "Block",
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+                          "name": "to",
+                          "nodeType": "Identifier",
+                          "overloadedDeclarations": [],
+                          "referencedDeclaration": 884,
+                          "src": "23514:2:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_address",
+                            "typeString": "address"
+                          }
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+                        "src": "23514:13:1",
+                        "typeDescriptions": {
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+                          "typeString": "function (address) view returns (bool)"
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+                          "typeDescriptions": {
+                            "typeIdentifier": "t_bool",
+                            "typeString": "bool"
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+                      "storageLocation": "default",
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+                        "name": "bytes4",
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+                          "typeIdentifier": "t_bytes4",
+                          "typeString": "bytes4"
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+                        "expression": {
+                          "argumentTypes": null,
+                          "id": 907,
+                          "name": "msg",
+                          "nodeType": "Identifier",
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+                          "referencedDeclaration": 1540,
+                          "src": "23630:3:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_magic_message",
+                            "typeString": "msg"
+                          }
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+                        "isConstant": false,
+                        "isLValue": false,
+                        "isPure": false,
+                        "lValueRequested": false,
+                        "memberName": "sender",
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+                        "src": "23630:10:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_address_payable",
+                          "typeString": "address payable"
+                        }
+                      },
+                      {
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+                        "id": 909,
+                        "name": "from",
+                        "nodeType": "Identifier",
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+                        "src": "23642:4:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        }
+                      },
+                      {
+                        "argumentTypes": null,
+                        "id": 910,
+                        "name": "tokenId",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
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+                        "src": "23648:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      },
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+                        "id": 911,
+                        "name": "_data",
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+                        "src": "23657:5:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_bytes_memory_ptr",
+                          "typeString": "bytes memory"
+                        }
+                      }
+                    ],
+                    "expression": {
+                      "argumentTypes": [
+                        {
+                          "typeIdentifier": "t_address_payable",
+                          "typeString": "address payable"
+                        },
+                        {
+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        },
+                        {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        },
+                        {
+                          "typeIdentifier": "t_bytes_memory_ptr",
+                          "typeString": "bytes memory"
+                        }
+                      ],
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+                        "arguments": [
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+                            "argumentTypes": null,
+                            "id": 904,
+                            "name": "to",
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+                            "src": "23609:2:1",
+                            "typeDescriptions": {
+                              "typeIdentifier": "t_address",
+                              "typeString": "address"
+                            }
+                          }
+                        ],
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+                            {
+                              "typeIdentifier": "t_address",
+                              "typeString": "address"
+                            }
+                          ],
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+                          "name": "IERC721Receiver",
+                          "nodeType": "Identifier",
+                          "overloadedDeclarations": [],
+                          "referencedDeclaration": 139,
+                          "src": "23593:15:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_type$_t_contract$_IERC721Receiver_$139_$",
+                            "typeString": "type(contract IERC721Receiver)"
+                          }
+                        },
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+                        "isLValue": false,
+                        "isPure": false,
+                        "kind": "typeConversion",
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+                        "nodeType": "FunctionCall",
+                        "src": "23593:19:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_contract$_IERC721Receiver_$139",
+                          "typeString": "contract IERC721Receiver"
+                        }
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+                      "src": "23593:36:1",
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+                        "typeString": "function (address,address,uint256,bytes memory) external returns (bytes4)"
+                      }
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+                      "typeString": "bytes4"
+                    }
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+                  "src": "23577:86:1"
+                },
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+                    "components": [
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+                        "argumentTypes": null,
+                        "commonType": {
+                          "typeIdentifier": "t_bytes4",
+                          "typeString": "bytes4"
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+                        "lValueRequested": false,
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+                          "name": "retval",
+                          "nodeType": "Identifier",
+                          "overloadedDeclarations": [],
+                          "referencedDeclaration": 902,
+                          "src": "23681:6:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_bytes4",
+                            "typeString": "bytes4"
+                          }
+                        },
+                        "nodeType": "BinaryOperation",
+                        "operator": "==",
+                        "rightExpression": {
+                          "argumentTypes": null,
+                          "id": 915,
+                          "name": "_ERC721_RECEIVED",
+                          "nodeType": "Identifier",
+                          "overloadedDeclarations": [],
+                          "referencedDeclaration": 403,
+                          "src": "23691:16:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_bytes4",
+                            "typeString": "bytes4"
+                          }
+                        },
+                        "src": "23681:26:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_bool",
+                          "typeString": "bool"
+                        }
+                      }
+                    ],
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+                    "isConstant": false,
+                    "isInlineArray": false,
+                    "isLValue": false,
+                    "isPure": false,
+                    "lValueRequested": false,
+                    "nodeType": "TupleExpression",
+                    "src": "23680:28:1",
+                    "typeDescriptions": {
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+                    }
+                  },
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+                  "id": 918,
+                  "nodeType": "Return",
+                  "src": "23673:35:1"
+                }
+              ]
+            },
+            "documentation": "@dev Internal function to invoke `onERC721Received` on a target address.\nThe call is not executed if the target address is not a contract.\n     * This function is deprecated.\n@param from address representing the previous owner of the given token ID\n@param to target address that will receive the tokens\n@param tokenId uint256 ID of the token to be transferred\n@param _data bytes optional data to send along with the call\n@return bool whether the call correctly returned the expected magic value",
+            "id": 920,
+            "implemented": true,
+            "kind": "function",
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+            "name": "_checkOnERC721Received",
+            "nodeType": "FunctionDefinition",
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+                  "name": "from",
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+                  "scope": 920,
+                  "src": "23400:12:1",
+                  "stateVariable": false,
+                  "storageLocation": "default",
+                  "typeDescriptions": {
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+                    "typeString": "address"
+                  },
+                  "typeName": {
+                    "id": 881,
+                    "name": "address",
+                    "nodeType": "ElementaryTypeName",
+                    "src": "23400:7:1",
+                    "stateMutability": "nonpayable",
+                    "typeDescriptions": {
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+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                },
+                {
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+                  "id": 884,
+                  "name": "to",
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+                  "scope": 920,
+                  "src": "23414:10:1",
+                  "stateVariable": false,
+                  "storageLocation": "default",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_address",
+                    "typeString": "address"
+                  },
+                  "typeName": {
+                    "id": 883,
+                    "name": "address",
+                    "nodeType": "ElementaryTypeName",
+                    "src": "23414:7:1",
+                    "stateMutability": "nonpayable",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_address",
+                      "typeString": "address"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                },
+                {
+                  "constant": false,
+                  "id": 886,
+                  "name": "tokenId",
+                  "nodeType": "VariableDeclaration",
+                  "scope": 920,
+                  "src": "23426:15:1",
+                  "stateVariable": false,
+                  "storageLocation": "default",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_uint256",
+                    "typeString": "uint256"
+                  },
+                  "typeName": {
+                    "id": 885,
+                    "name": "uint256",
+                    "nodeType": "ElementaryTypeName",
+                    "src": "23426:7:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_uint256",
+                      "typeString": "uint256"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                },
+                {
+                  "constant": false,
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+                      "id": 1052,
+                      "name": "_allTokens",
+                      "nodeType": "Identifier",
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+                      "src": "27266:10:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_array$_t_uint256_$dyn_storage",
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+                      }
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+                          "typeString": "address"
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+                        "src": "27776:2:1",
+                        "typeDescriptions": {
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+                        "name": "tokenId",
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+                        "src": "27780:7:1",
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+                          "typeString": "uint256"
+                        }
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+                          "typeString": "address"
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+                          "typeString": "address"
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+                          "typeString": "address"
+                        },
+                        {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
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+                      "typeString": "address"
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+                          "typeString": "uint256"
+                        }
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+                      "name": "_addTokenToAllTokensEnumeration",
+                      "nodeType": "Identifier",
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+                      "referencedDeclaration": 1195,
+                      "src": "28310:31:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_function_internal_nonpayable$_t_uint256_$returns$__$",
+                        "typeString": "function (uint256)"
+                      }
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+                    "isPure": false,
+                    "kind": "functionCall",
+                    "lValueRequested": false,
+                    "names": [],
+                    "nodeType": "FunctionCall",
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+                    }
+                  },
+                  "id": 1107,
+                  "nodeType": "ExpressionStatement",
+                  "src": "28310:40:1"
+                }
+              ]
+            },
+            "documentation": "@dev Internal function to mint a new token.\nReverts if the given token ID already exists.\n@param to address the beneficiary that will own the minted token\n@param tokenId uint256 ID of the token to be minted",
+            "id": 1109,
+            "implemented": true,
+            "kind": "function",
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+            "name": "_mint",
+            "nodeType": "FunctionDefinition",
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+              "nodeType": "ParameterList",
+              "parameters": [
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+                  "id": 1087,
+                  "name": "to",
+                  "nodeType": "VariableDeclaration",
+                  "scope": 1109,
+                  "src": "28176:10:1",
+                  "stateVariable": false,
+                  "storageLocation": "default",
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+                    "typeIdentifier": "t_address",
+                    "typeString": "address"
+                  },
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+                    "name": "address",
+                    "nodeType": "ElementaryTypeName",
+                    "src": "28176:7:1",
+                    "stateMutability": "nonpayable",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_address",
+                      "typeString": "address"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                },
+                {
+                  "constant": false,
+                  "id": 1089,
+                  "name": "tokenId",
+                  "nodeType": "VariableDeclaration",
+                  "scope": 1109,
+                  "src": "28188:15:1",
+                  "stateVariable": false,
+                  "storageLocation": "default",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_uint256",
+                    "typeString": "uint256"
+                  },
+                  "typeName": {
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+                    "name": "uint256",
+                    "nodeType": "ElementaryTypeName",
+                    "src": "28188:7:1",
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+                      "typeIdentifier": "t_uint256",
+                      "typeString": "uint256"
+                    }
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+                  "value": null,
+                  "visibility": "internal"
+                }
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+            },
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+              "nodeType": "ParameterList",
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+            "src": "28161:196:1",
+            "stateMutability": "nonpayable",
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+            "visibility": "internal"
+          },
+          {
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+              "id": 1138,
+              "nodeType": "Block",
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+                    "arguments": [
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+                        "id": 1119,
+                        "name": "owner",
+                        "nodeType": "Identifier",
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+                        "src": "28710:5:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        }
+                      },
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+                        "id": 1120,
+                        "name": "tokenId",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 1113,
+                        "src": "28717:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      }
+                    ],
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+                      "argumentTypes": [
+                        {
+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        },
+                        {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      ],
+                      "expression": {
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+                        "id": 1116,
+                        "name": "super",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 1572,
+                        "src": "28698:5:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_super$_ERC721Enumerable_$1302",
+                          "typeString": "contract super ERC721Enumerable"
+                        }
+                      },
+                      "id": 1118,
+                      "isConstant": false,
+                      "isLValue": false,
+                      "isPure": false,
+                      "lValueRequested": false,
+                      "memberName": "_burn",
+                      "nodeType": "MemberAccess",
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+                      "src": "28698:11:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_function_internal_nonpayable$_t_address_$_t_uint256_$returns$__$",
+                        "typeString": "function (address,uint256)"
+                      }
+                    },
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+                    "isConstant": false,
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+                    "kind": "functionCall",
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+                    "nodeType": "FunctionCall",
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+                      "typeString": "tuple()"
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+                },
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+                        "id": 1124,
+                        "name": "owner",
+                        "nodeType": "Identifier",
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+                        "referencedDeclaration": 1111,
+                        "src": "28769:5:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        }
+                      },
+                      {
+                        "argumentTypes": null,
+                        "id": 1125,
+                        "name": "tokenId",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 1113,
+                        "src": "28776:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      }
+                    ],
+                    "expression": {
+                      "argumentTypes": [
+                        {
+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        },
+                        {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      ],
+                      "id": 1123,
+                      "name": "_removeTokenFromOwnerEnumeration",
+                      "nodeType": "Identifier",
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+                      "referencedDeclaration": 1252,
+                      "src": "28736:32:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_function_internal_nonpayable$_t_address_$_t_uint256_$returns$__$",
+                        "typeString": "function (address,uint256)"
+                      }
+                    },
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+                    "isConstant": false,
+                    "isLValue": false,
+                    "isPure": false,
+                    "kind": "functionCall",
+                    "lValueRequested": false,
+                    "names": [],
+                    "nodeType": "FunctionCall",
+                    "src": "28736:48:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_tuple$__$",
+                      "typeString": "tuple()"
+                    }
+                  },
+                  "id": 1127,
+                  "nodeType": "ExpressionStatement",
+                  "src": "28736:48:1"
+                },
+                {
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+                    "isLValue": false,
+                    "isPure": false,
+                    "lValueRequested": false,
+                    "leftHandSide": {
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+                      "baseExpression": {
+                        "argumentTypes": null,
+                        "id": 1128,
+                        "name": "_ownedTokensIndex",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 985,
+                        "src": "28903:17:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_mapping$_t_uint256_$_t_uint256_$",
+                          "typeString": "mapping(uint256 => uint256)"
+                        }
+                      },
+                      "id": 1130,
+                      "indexExpression": {
+                        "argumentTypes": null,
+                        "id": 1129,
+                        "name": "tokenId",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 1113,
+                        "src": "28921:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      },
+                      "isConstant": false,
+                      "isLValue": true,
+                      "isPure": false,
+                      "lValueRequested": true,
+                      "nodeType": "IndexAccess",
+                      "src": "28903:26:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_uint256",
+                        "typeString": "uint256"
+                      }
+                    },
+                    "nodeType": "Assignment",
+                    "operator": "=",
+                    "rightHandSide": {
+                      "argumentTypes": null,
+                      "hexValue": "30",
+                      "id": 1131,
+                      "isConstant": false,
+                      "isLValue": false,
+                      "isPure": true,
+                      "kind": "number",
+                      "lValueRequested": false,
+                      "nodeType": "Literal",
+                      "src": "28932:1:1",
+                      "subdenomination": null,
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_rational_0_by_1",
+                        "typeString": "int_const 0"
+                      },
+                      "value": "0"
+                    },
+                    "src": "28903:30:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_uint256",
+                      "typeString": "uint256"
+                    }
+                  },
+                  "id": 1133,
+                  "nodeType": "ExpressionStatement",
+                  "src": "28903:30:1"
+                },
+                {
+                  "expression": {
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+                    "arguments": [
+                      {
+                        "argumentTypes": null,
+                        "id": 1135,
+                        "name": "tokenId",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 1113,
+                        "src": "28981:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      }
+                    ],
+                    "expression": {
+                      "argumentTypes": [
+                        {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      ],
+                      "id": 1134,
+                      "name": "_removeTokenFromAllTokensEnumeration",
+                      "nodeType": "Identifier",
+                      "overloadedDeclarations": [],
+                      "referencedDeclaration": 1301,
+                      "src": "28944:36:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_function_internal_nonpayable$_t_uint256_$returns$__$",
+                        "typeString": "function (uint256)"
+                      }
+                    },
+                    "id": 1136,
+                    "isConstant": false,
+                    "isLValue": false,
+                    "isPure": false,
+                    "kind": "functionCall",
+                    "lValueRequested": false,
+                    "names": [],
+                    "nodeType": "FunctionCall",
+                    "src": "28944:45:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_tuple$__$",
+                      "typeString": "tuple()"
+                    }
+                  },
+                  "id": 1137,
+                  "nodeType": "ExpressionStatement",
+                  "src": "28944:45:1"
+                }
+              ]
+            },
+            "documentation": "@dev Internal function to burn a specific token.\nReverts if the token does not exist.\nDeprecated, use _burn(uint256) instead.\n@param owner owner of the token to burn\n@param tokenId uint256 ID of the token being burned",
+            "id": 1139,
+            "implemented": true,
+            "kind": "function",
+            "modifiers": [],
+            "name": "_burn",
+            "nodeType": "FunctionDefinition",
+            "parameters": {
+              "id": 1114,
+              "nodeType": "ParameterList",
+              "parameters": [
+                {
+                  "constant": false,
+                  "id": 1111,
+                  "name": "owner",
+                  "nodeType": "VariableDeclaration",
+                  "scope": 1139,
+                  "src": "28647:13:1",
+                  "stateVariable": false,
+                  "storageLocation": "default",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_address",
+                    "typeString": "address"
+                  },
+                  "typeName": {
+                    "id": 1110,
+                    "name": "address",
+                    "nodeType": "ElementaryTypeName",
+                    "src": "28647:7:1",
+                    "stateMutability": "nonpayable",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_address",
+                      "typeString": "address"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                },
+                {
+                  "constant": false,
+                  "id": 1113,
+                  "name": "tokenId",
+                  "nodeType": "VariableDeclaration",
+                  "scope": 1139,
+                  "src": "28662:15:1",
+                  "stateVariable": false,
+                  "storageLocation": "default",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_uint256",
+                    "typeString": "uint256"
+                  },
+                  "typeName": {
+                    "id": 1112,
+                    "name": "uint256",
+                    "nodeType": "ElementaryTypeName",
+                    "src": "28662:7:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_uint256",
+                      "typeString": "uint256"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                }
+              ],
+              "src": "28646:32:1"
+            },
+            "returnParameters": {
+              "id": 1115,
+              "nodeType": "ParameterList",
+              "parameters": [],
+              "src": "28688:0:1"
+            },
+            "scope": 1302,
+            "src": "28632:364:1",
+            "stateMutability": "nonpayable",
+            "superFunction": 811,
+            "visibility": "internal"
+          },
+          {
+            "body": {
+              "id": 1151,
+              "nodeType": "Block",
+              "src": "29282:43:1",
+              "statements": [
+                {
+                  "expression": {
+                    "argumentTypes": null,
+                    "baseExpression": {
+                      "argumentTypes": null,
+                      "id": 1147,
+                      "name": "_ownedTokens",
+                      "nodeType": "Identifier",
+                      "overloadedDeclarations": [],
+                      "referencedDeclaration": 981,
+                      "src": "29299:12:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_mapping$_t_address_$_t_array$_t_uint256_$dyn_storage_$",
+                        "typeString": "mapping(address => uint256[] storage ref)"
+                      }
+                    },
+                    "id": 1149,
+                    "indexExpression": {
+                      "argumentTypes": null,
+                      "id": 1148,
+                      "name": "owner",
+                      "nodeType": "Identifier",
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+                      "referencedDeclaration": 1141,
+                      "src": "29312:5:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_address",
+                        "typeString": "address"
+                      }
+                    },
+                    "isConstant": false,
+                    "isLValue": true,
+                    "isPure": false,
+                    "lValueRequested": false,
+                    "nodeType": "IndexAccess",
+                    "src": "29299:19:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_array$_t_uint256_$dyn_storage",
+                      "typeString": "uint256[] storage ref"
+                    }
+                  },
+                  "functionReturnParameters": 1146,
+                  "id": 1150,
+                  "nodeType": "Return",
+                  "src": "29292:26:1"
+                }
+              ]
+            },
+            "documentation": "@dev Gets the list of token IDs of the requested owner.\n@param owner address owning the tokens\n@return uint256[] List of token IDs owned by the requested address",
+            "id": 1152,
+            "implemented": true,
+            "kind": "function",
+            "modifiers": [],
+            "name": "_tokensOfOwner",
+            "nodeType": "FunctionDefinition",
+            "parameters": {
+              "id": 1142,
+              "nodeType": "ParameterList",
+              "parameters": [
+                {
+                  "constant": false,
+                  "id": 1141,
+                  "name": "owner",
+                  "nodeType": "VariableDeclaration",
+                  "scope": 1152,
+                  "src": "29225:13:1",
+                  "stateVariable": false,
+                  "storageLocation": "default",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_address",
+                    "typeString": "address"
+                  },
+                  "typeName": {
+                    "id": 1140,
+                    "name": "address",
+                    "nodeType": "ElementaryTypeName",
+                    "src": "29225:7:1",
+                    "stateMutability": "nonpayable",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_address",
+                      "typeString": "address"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                }
+              ],
+              "src": "29224:15:1"
+            },
+            "returnParameters": {
+              "id": 1146,
+              "nodeType": "ParameterList",
+              "parameters": [
+                {
+                  "constant": false,
+                  "id": 1145,
+                  "name": "",
+                  "nodeType": "VariableDeclaration",
+                  "scope": 1152,
+                  "src": "29263:17:1",
+                  "stateVariable": false,
+                  "storageLocation": "storage",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_array$_t_uint256_$dyn_storage_ptr",
+                    "typeString": "uint256[]"
+                  },
+                  "typeName": {
+                    "baseType": {
+                      "id": 1143,
+                      "name": "uint256",
+                      "nodeType": "ElementaryTypeName",
+                      "src": "29263:7:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_uint256",
+                        "typeString": "uint256"
+                      }
+                    },
+                    "id": 1144,
+                    "length": null,
+                    "nodeType": "ArrayTypeName",
+                    "src": "29263:9:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_array$_t_uint256_$dyn_storage_ptr",
+                      "typeString": "uint256[]"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                }
+              ],
+              "src": "29262:19:1"
+            },
+            "scope": 1302,
+            "src": "29201:124:1",
+            "stateMutability": "view",
+            "superFunction": null,
+            "visibility": "internal"
+          },
+          {
+            "body": {
+              "id": 1175,
+              "nodeType": "Block",
+              "src": "29693:109:1",
+              "statements": [
+                {
+                  "expression": {
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+                    "id": 1166,
+                    "isConstant": false,
+                    "isLValue": false,
+                    "isPure": false,
+                    "lValueRequested": false,
+                    "leftHandSide": {
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+                      "baseExpression": {
+                        "argumentTypes": null,
+                        "id": 1159,
+                        "name": "_ownedTokensIndex",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 985,
+                        "src": "29703:17:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_mapping$_t_uint256_$_t_uint256_$",
+                          "typeString": "mapping(uint256 => uint256)"
+                        }
+                      },
+                      "id": 1161,
+                      "indexExpression": {
+                        "argumentTypes": null,
+                        "id": 1160,
+                        "name": "tokenId",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 1156,
+                        "src": "29721:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      },
+                      "isConstant": false,
+                      "isLValue": true,
+                      "isPure": false,
+                      "lValueRequested": true,
+                      "nodeType": "IndexAccess",
+                      "src": "29703:26:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_uint256",
+                        "typeString": "uint256"
+                      }
+                    },
+                    "nodeType": "Assignment",
+                    "operator": "=",
+                    "rightHandSide": {
+                      "argumentTypes": null,
+                      "expression": {
+                        "argumentTypes": null,
+                        "baseExpression": {
+                          "argumentTypes": null,
+                          "id": 1162,
+                          "name": "_ownedTokens",
+                          "nodeType": "Identifier",
+                          "overloadedDeclarations": [],
+                          "referencedDeclaration": 981,
+                          "src": "29732:12:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_mapping$_t_address_$_t_array$_t_uint256_$dyn_storage_$",
+                            "typeString": "mapping(address => uint256[] storage ref)"
+                          }
+                        },
+                        "id": 1164,
+                        "indexExpression": {
+                          "argumentTypes": null,
+                          "id": 1163,
+                          "name": "to",
+                          "nodeType": "Identifier",
+                          "overloadedDeclarations": [],
+                          "referencedDeclaration": 1154,
+                          "src": "29745:2:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_address",
+                            "typeString": "address"
+                          }
+                        },
+                        "isConstant": false,
+                        "isLValue": true,
+                        "isPure": false,
+                        "lValueRequested": false,
+                        "nodeType": "IndexAccess",
+                        "src": "29732:16:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_array$_t_uint256_$dyn_storage",
+                          "typeString": "uint256[] storage ref"
+                        }
+                      },
+                      "id": 1165,
+                      "isConstant": false,
+                      "isLValue": true,
+                      "isPure": false,
+                      "lValueRequested": false,
+                      "memberName": "length",
+                      "nodeType": "MemberAccess",
+                      "referencedDeclaration": null,
+                      "src": "29732:23:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_uint256",
+                        "typeString": "uint256"
+                      }
+                    },
+                    "src": "29703:52:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_uint256",
+                      "typeString": "uint256"
+                    }
+                  },
+                  "id": 1167,
+                  "nodeType": "ExpressionStatement",
+                  "src": "29703:52:1"
+                },
+                {
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+                    "arguments": [
+                      {
+                        "argumentTypes": null,
+                        "id": 1172,
+                        "name": "tokenId",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 1156,
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+                          "src": "29765:12:1",
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+                      "src": "29765:21:1",
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+                              "typeString": "uint256"
+                            }
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+                          "isPure": false,
+                          "lValueRequested": false,
+                          "nodeType": "IndexAccess",
+                          "src": "31319:34:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_uint256",
+                            "typeString": "uint256"
+                          }
+                        },
+                        "nodeType": "VariableDeclarationStatement",
+                        "src": "31297:56:1"
+                      },
+                      {
+                        "expression": {
+                          "argumentTypes": null,
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+                          "lValueRequested": false,
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+                            "baseExpression": {
+                              "argumentTypes": null,
+                              "baseExpression": {
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+                                "id": 1229,
+                                "name": "_ownedTokens",
+                                "nodeType": "Identifier",
+                                "overloadedDeclarations": [],
+                                "referencedDeclaration": 981,
+                                "src": "31368:12:1",
+                                "typeDescriptions": {
+                                  "typeIdentifier": "t_mapping$_t_address_$_t_array$_t_uint256_$dyn_storage_$",
+                                  "typeString": "mapping(address => uint256[] storage ref)"
+                                }
+                              },
+                              "id": 1232,
+                              "indexExpression": {
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+                                "name": "from",
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+                                "overloadedDeclarations": [],
+                                "referencedDeclaration": 1197,
+                                "src": "31381:4:1",
+                                "typeDescriptions": {
+                                  "typeIdentifier": "t_address",
+                                  "typeString": "address"
+                                }
+                              },
+                              "isConstant": false,
+                              "isLValue": true,
+                              "isPure": false,
+                              "lValueRequested": false,
+                              "nodeType": "IndexAccess",
+                              "src": "31368:18:1",
+                              "typeDescriptions": {
+                                "typeIdentifier": "t_array$_t_uint256_$dyn_storage",
+                                "typeString": "uint256[] storage ref"
+                              }
+                            },
+                            "id": 1233,
+                            "indexExpression": {
+                              "argumentTypes": null,
+                              "id": 1231,
+                              "name": "tokenIndex",
+                              "nodeType": "Identifier",
+                              "overloadedDeclarations": [],
+                              "referencedDeclaration": 1213,
+                              "src": "31387:10:1",
+                              "typeDescriptions": {
+                                "typeIdentifier": "t_uint256",
+                                "typeString": "uint256"
+                              }
+                            },
+                            "isConstant": false,
+                            "isLValue": true,
+                            "isPure": false,
+                            "lValueRequested": true,
+                            "nodeType": "IndexAccess",
+                            "src": "31368:30:1",
+                            "typeDescriptions": {
+                              "typeIdentifier": "t_uint256",
+                              "typeString": "uint256"
+                            }
+                          },
+                          "nodeType": "Assignment",
+                          "operator": "=",
+                          "rightHandSide": {
+                            "argumentTypes": null,
+                            "id": 1234,
+                            "name": "lastTokenId",
+                            "nodeType": "Identifier",
+                            "overloadedDeclarations": [],
+                            "referencedDeclaration": 1222,
+                            "src": "31401:11:1",
+                            "typeDescriptions": {
+                              "typeIdentifier": "t_uint256",
+                              "typeString": "uint256"
+                            }
+                          },
+                          "src": "31368:44:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_uint256",
+                            "typeString": "uint256"
+                          }
+                        },
+                        "id": 1236,
+                        "nodeType": "ExpressionStatement",
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+                      },
+                      {
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+                          "id": 1241,
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+                          "leftHandSide": {
+                            "argumentTypes": null,
+                            "baseExpression": {
+                              "argumentTypes": null,
+                              "id": 1237,
+                              "name": "_ownedTokensIndex",
+                              "nodeType": "Identifier",
+                              "overloadedDeclarations": [],
+                              "referencedDeclaration": 985,
+                              "src": "31484:17:1",
+                              "typeDescriptions": {
+                                "typeIdentifier": "t_mapping$_t_uint256_$_t_uint256_$",
+                                "typeString": "mapping(uint256 => uint256)"
+                              }
+                            },
+                            "id": 1239,
+                            "indexExpression": {
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+                              "id": 1238,
+                              "name": "lastTokenId",
+                              "nodeType": "Identifier",
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+                              "referencedDeclaration": 1222,
+                              "src": "31502:11:1",
+                              "typeDescriptions": {
+                                "typeIdentifier": "t_uint256",
+                                "typeString": "uint256"
+                              }
+                            },
+                            "isConstant": false,
+                            "isLValue": true,
+                            "isPure": false,
+                            "lValueRequested": true,
+                            "nodeType": "IndexAccess",
+                            "src": "31484:30:1",
+                            "typeDescriptions": {
+                              "typeIdentifier": "t_uint256",
+                              "typeString": "uint256"
+                            }
+                          },
+                          "nodeType": "Assignment",
+                          "operator": "=",
+                          "rightHandSide": {
+                            "argumentTypes": null,
+                            "id": 1240,
+                            "name": "tokenIndex",
+                            "nodeType": "Identifier",
+                            "overloadedDeclarations": [],
+                            "referencedDeclaration": 1213,
+                            "src": "31517:10:1",
+                            "typeDescriptions": {
+                              "typeIdentifier": "t_uint256",
+                              "typeString": "uint256"
+                            }
+                          },
+                          "src": "31484:43:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_uint256",
+                            "typeString": "uint256"
+                          }
+                        },
+                        "id": 1242,
+                        "nodeType": "ExpressionStatement",
+                        "src": "31484:43:1"
+                      }
+                    ]
+                  }
+                },
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+                    "id": 1249,
+                    "isConstant": false,
+                    "isLValue": false,
+                    "isPure": false,
+                    "lValueRequested": false,
+                    "nodeType": "UnaryOperation",
+                    "operator": "--",
+                    "prefix": false,
+                    "src": "31658:27:1",
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+                      "expression": {
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+                        "baseExpression": {
+                          "argumentTypes": null,
+                          "id": 1245,
+                          "name": "_ownedTokens",
+                          "nodeType": "Identifier",
+                          "overloadedDeclarations": [],
+                          "referencedDeclaration": 981,
+                          "src": "31658:12:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_mapping$_t_address_$_t_array$_t_uint256_$dyn_storage_$",
+                            "typeString": "mapping(address => uint256[] storage ref)"
+                          }
+                        },
+                        "id": 1247,
+                        "indexExpression": {
+                          "argumentTypes": null,
+                          "id": 1246,
+                          "name": "from",
+                          "nodeType": "Identifier",
+                          "overloadedDeclarations": [],
+                          "referencedDeclaration": 1197,
+                          "src": "31671:4:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_address",
+                            "typeString": "address"
+                          }
+                        },
+                        "isConstant": false,
+                        "isLValue": true,
+                        "isPure": false,
+                        "lValueRequested": false,
+                        "nodeType": "IndexAccess",
+                        "src": "31658:18:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_array$_t_uint256_$dyn_storage",
+                          "typeString": "uint256[] storage ref"
+                        }
+                      },
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+                      "isConstant": false,
+                      "isLValue": true,
+                      "isPure": false,
+                      "lValueRequested": true,
+                      "memberName": "length",
+                      "nodeType": "MemberAccess",
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+                      "src": "31658:25:1",
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+                        "typeIdentifier": "t_uint256",
+                        "typeString": "uint256"
+                      }
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+                      "typeString": "uint256"
+                    }
+                  },
+                  "id": 1250,
+                  "nodeType": "ExpressionStatement",
+                  "src": "31658:27:1"
+                }
+              ]
+            },
+            "documentation": "@dev Private function to remove a token from this extension's ownership-tracking data structures. Note that\nwhile the token is not assigned a new owner, the _ownedTokensIndex mapping is _not_ updated: this allows for\ngas optimizations e.g. when performing a transfer operation (avoiding double writes).\nThis has O(1) time complexity, but alters the order of the _ownedTokens array.\n@param from address representing the previous owner of the given token ID\n@param tokenId uint256 ID of the token to be removed from the tokens list of the given address",
+            "id": 1252,
+            "implemented": true,
+            "kind": "function",
+            "modifiers": [],
+            "name": "_removeTokenFromOwnerEnumeration",
+            "nodeType": "FunctionDefinition",
+            "parameters": {
+              "id": 1200,
+              "nodeType": "ParameterList",
+              "parameters": [
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+                  "id": 1197,
+                  "name": "from",
+                  "nodeType": "VariableDeclaration",
+                  "scope": 1252,
+                  "src": "30815:12:1",
+                  "stateVariable": false,
+                  "storageLocation": "default",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_address",
+                    "typeString": "address"
+                  },
+                  "typeName": {
+                    "id": 1196,
+                    "name": "address",
+                    "nodeType": "ElementaryTypeName",
+                    "src": "30815:7:1",
+                    "stateMutability": "nonpayable",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_address",
+                      "typeString": "address"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                },
+                {
+                  "constant": false,
+                  "id": 1199,
+                  "name": "tokenId",
+                  "nodeType": "VariableDeclaration",
+                  "scope": 1252,
+                  "src": "30829:15:1",
+                  "stateVariable": false,
+                  "storageLocation": "default",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_uint256",
+                    "typeString": "uint256"
+                  },
+                  "typeName": {
+                    "id": 1198,
+                    "name": "uint256",
+                    "nodeType": "ElementaryTypeName",
+                    "src": "30829:7:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_uint256",
+                      "typeString": "uint256"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                }
+              ],
+              "src": "30814:31:1"
+            },
+            "returnParameters": {
+              "id": 1201,
+              "nodeType": "ParameterList",
+              "parameters": [],
+              "src": "30854:0:1"
+            },
+            "scope": 1302,
+            "src": "30773:1128:1",
+            "stateMutability": "nonpayable",
+            "superFunction": null,
+            "visibility": "private"
+          },
+          {
+            "body": {
+              "id": 1300,
+              "nodeType": "Block",
+              "src": "32260:993:1",
+              "statements": [
+                {
+                  "assignments": [
+                    1258
+                  ],
+                  "declarations": [
+                    {
+                      "constant": false,
+                      "id": 1258,
+                      "name": "lastTokenIndex",
+                      "nodeType": "VariableDeclaration",
+                      "scope": 1300,
+                      "src": "32438:22:1",
+                      "stateVariable": false,
+                      "storageLocation": "default",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_uint256",
+                        "typeString": "uint256"
+                      },
+                      "typeName": {
+                        "id": 1257,
+                        "name": "uint256",
+                        "nodeType": "ElementaryTypeName",
+                        "src": "32438:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      },
+                      "value": null,
+                      "visibility": "internal"
+                    }
+                  ],
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+                  "initialValue": {
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+                    "arguments": [
+                      {
+                        "argumentTypes": null,
+                        "hexValue": "31",
+                        "id": 1262,
+                        "isConstant": false,
+                        "isLValue": false,
+                        "isPure": true,
+                        "kind": "number",
+                        "lValueRequested": false,
+                        "nodeType": "Literal",
+                        "src": "32485:1:1",
+                        "subdenomination": null,
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_rational_1_by_1",
+                          "typeString": "int_const 1"
+                        },
+                        "value": "1"
+                      }
+                    ],
+                    "expression": {
+                      "argumentTypes": [
+                        {
+                          "typeIdentifier": "t_rational_1_by_1",
+                          "typeString": "int_const 1"
+                        }
+                      ],
+                      "expression": {
+                        "argumentTypes": null,
+                        "expression": {
+                          "argumentTypes": null,
+                          "id": 1259,
+                          "name": "_allTokens",
+                          "nodeType": "Identifier",
+                          "overloadedDeclarations": [],
+                          "referencedDeclaration": 988,
+                          "src": "32463:10:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_array$_t_uint256_$dyn_storage",
+                            "typeString": "uint256[] storage ref"
+                          }
+                        },
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+                        "isConstant": false,
+                        "isLValue": true,
+                        "isPure": false,
+                        "lValueRequested": false,
+                        "memberName": "length",
+                        "nodeType": "MemberAccess",
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+                        "src": "32463:17:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
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+                      "isPure": false,
+                      "lValueRequested": false,
+                      "memberName": "sub",
+                      "nodeType": "MemberAccess",
+                      "referencedDeclaration": 190,
+                      "src": "32463:21:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_function_internal_pure$_t_uint256_$_t_uint256_$returns$_t_uint256_$bound_to$_t_uint256_$",
+                        "typeString": "function (uint256,uint256) pure returns (uint256)"
+                      }
+                    },
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+                    "isConstant": false,
+                    "isLValue": false,
+                    "isPure": false,
+                    "kind": "functionCall",
+                    "lValueRequested": false,
+                    "names": [],
+                    "nodeType": "FunctionCall",
+                    "src": "32463:24:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_uint256",
+                      "typeString": "uint256"
+                    }
+                  },
+                  "nodeType": "VariableDeclarationStatement",
+                  "src": "32438:49:1"
+                },
+                {
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+                      "name": "tokenIndex",
+                      "nodeType": "VariableDeclaration",
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+                      "src": "32497:18:1",
+                      "stateVariable": false,
+                      "storageLocation": "default",
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+                        "typeIdentifier": "t_uint256",
+                        "typeString": "uint256"
+                      },
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+                        "id": 1265,
+                        "name": "uint256",
+                        "nodeType": "ElementaryTypeName",
+                        "src": "32497:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      },
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+                      "visibility": "internal"
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+                  "initialValue": {
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+                      "id": 1267,
+                      "name": "_allTokensIndex",
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+                      "src": "32518:15:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_mapping$_t_uint256_$_t_uint256_$",
+                        "typeString": "mapping(uint256 => uint256)"
+                      }
+                    },
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+                    "indexExpression": {
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+                      "id": 1268,
+                      "name": "tokenId",
+                      "nodeType": "Identifier",
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+                      "src": "32534:7:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_uint256",
+                        "typeString": "uint256"
+                      }
+                    },
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+                    "isPure": false,
+                    "lValueRequested": false,
+                    "nodeType": "IndexAccess",
+                    "src": "32518:24:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_uint256",
+                      "typeString": "uint256"
+                    }
+                  },
+                  "nodeType": "VariableDeclarationStatement",
+                  "src": "32497:45:1"
+                },
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+                  ],
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+                      "constant": false,
+                      "id": 1272,
+                      "name": "lastTokenId",
+                      "nodeType": "VariableDeclaration",
+                      "scope": 1300,
+                      "src": "32864:19:1",
+                      "stateVariable": false,
+                      "storageLocation": "default",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_uint256",
+                        "typeString": "uint256"
+                      },
+                      "typeName": {
+                        "id": 1271,
+                        "name": "uint256",
+                        "nodeType": "ElementaryTypeName",
+                        "src": "32864:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
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+                      "src": "32886:10:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_array$_t_uint256_$dyn_storage",
+                        "typeString": "uint256[] storage ref"
+                      }
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+                      "id": 1274,
+                      "name": "lastTokenIndex",
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+                      "src": "32897:14:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_uint256",
+                        "typeString": "uint256"
+                      }
+                    },
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+                    "isPure": false,
+                    "lValueRequested": false,
+                    "nodeType": "IndexAccess",
+                    "src": "32886:26:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_uint256",
+                      "typeString": "uint256"
+                    }
+                  },
+                  "nodeType": "VariableDeclarationStatement",
+                  "src": "32864:48:1"
+                },
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+                        "name": "_allTokens",
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+                        "src": "32923:10:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_array$_t_uint256_$dyn_storage",
+                          "typeString": "uint256[] storage ref"
+                        }
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+                        "name": "tokenIndex",
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+                        "src": "32934:10:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
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+                        "typeIdentifier": "t_uint256",
+                        "typeString": "uint256"
+                      }
+                    },
+                    "nodeType": "Assignment",
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+                      "name": "lastTokenId",
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+                      "referencedDeclaration": 1272,
+                      "src": "32948:11:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_uint256",
+                        "typeString": "uint256"
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+                        "referencedDeclaration": 992,
+                        "src": "33027:15:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_mapping$_t_uint256_$_t_uint256_$",
+                          "typeString": "mapping(uint256 => uint256)"
+                        }
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+                        "name": "lastTokenId",
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+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
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+                    "typeString": "uint256"
+                  },
+                  "typeName": {
+                    "id": 1397,
+                    "name": "uint256",
+                    "nodeType": "ElementaryTypeName",
+                    "src": "35749:7:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_uint256",
+                      "typeString": "uint256"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                },
+                {
+                  "constant": false,
+                  "id": 1400,
+                  "name": "uri",
+                  "nodeType": "VariableDeclaration",
+                  "scope": 1417,
+                  "src": "35766:17:1",
+                  "stateVariable": false,
+                  "storageLocation": "memory",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_string_memory_ptr",
+                    "typeString": "string"
+                  },
+                  "typeName": {
+                    "id": 1399,
+                    "name": "string",
+                    "nodeType": "ElementaryTypeName",
+                    "src": "35766:6:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_string_storage_ptr",
+                      "typeString": "string"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                }
+              ],
+              "src": "35748:36:1"
+            },
+            "returnParameters": {
+              "id": 1402,
+              "nodeType": "ParameterList",
+              "parameters": [],
+              "src": "35794:0:1"
+            },
+            "scope": 1448,
+            "src": "35727:192:1",
+            "stateMutability": "nonpayable",
+            "superFunction": null,
+            "visibility": "internal"
+          },
+          {
+            "body": {
+              "id": 1446,
+              "nodeType": "Block",
+              "src": "36268:184:1",
+              "statements": [
+                {
+                  "expression": {
+                    "argumentTypes": null,
+                    "arguments": [
+                      {
+                        "argumentTypes": null,
+                        "id": 1427,
+                        "name": "owner",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 1419,
+                        "src": "36290:5:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        }
+                      },
+                      {
+                        "argumentTypes": null,
+                        "id": 1428,
+                        "name": "tokenId",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 1421,
+                        "src": "36297:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      }
+                    ],
+                    "expression": {
+                      "argumentTypes": [
+                        {
+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        },
+                        {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      ],
+                      "expression": {
+                        "argumentTypes": null,
+                        "id": 1424,
+                        "name": "super",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 1576,
+                        "src": "36278:5:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_super$_ERC721Metadata_$1448",
+                          "typeString": "contract super ERC721Metadata"
+                        }
+                      },
+                      "id": 1426,
+                      "isConstant": false,
+                      "isLValue": false,
+                      "isPure": false,
+                      "lValueRequested": false,
+                      "memberName": "_burn",
+                      "nodeType": "MemberAccess",
+                      "referencedDeclaration": 811,
+                      "src": "36278:11:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_function_internal_nonpayable$_t_address_$_t_uint256_$returns$__$",
+                        "typeString": "function (address,uint256)"
+                      }
+                    },
+                    "id": 1429,
+                    "isConstant": false,
+                    "isLValue": false,
+                    "isPure": false,
+                    "kind": "functionCall",
+                    "lValueRequested": false,
+                    "names": [],
+                    "nodeType": "FunctionCall",
+                    "src": "36278:27:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_tuple$__$",
+                      "typeString": "tuple()"
+                    }
+                  },
+                  "id": 1430,
+                  "nodeType": "ExpressionStatement",
+                  "src": "36278:27:1"
+                },
+                {
+                  "condition": {
+                    "argumentTypes": null,
+                    "commonType": {
+                      "typeIdentifier": "t_uint256",
+                      "typeString": "uint256"
+                    },
+                    "id": 1438,
+                    "isConstant": false,
+                    "isLValue": false,
+                    "isPure": false,
+                    "lValueRequested": false,
+                    "leftExpression": {
+                      "argumentTypes": null,
+                      "expression": {
+                        "argumentTypes": null,
+                        "arguments": [
+                          {
+                            "argumentTypes": null,
+                            "baseExpression": {
+                              "argumentTypes": null,
+                              "id": 1432,
+                              "name": "_tokenURIs",
+                              "nodeType": "Identifier",
+                              "overloadedDeclarations": [],
+                              "referencedDeclaration": 1338,
+                              "src": "36361:10:1",
+                              "typeDescriptions": {
+                                "typeIdentifier": "t_mapping$_t_uint256_$_t_string_storage_$",
+                                "typeString": "mapping(uint256 => string storage ref)"
+                              }
+                            },
+                            "id": 1434,
+                            "indexExpression": {
+                              "argumentTypes": null,
+                              "id": 1433,
+                              "name": "tokenId",
+                              "nodeType": "Identifier",
+                              "overloadedDeclarations": [],
+                              "referencedDeclaration": 1421,
+                              "src": "36372:7:1",
+                              "typeDescriptions": {
+                                "typeIdentifier": "t_uint256",
+                                "typeString": "uint256"
+                              }
+                            },
+                            "isConstant": false,
+                            "isLValue": true,
+                            "isPure": false,
+                            "lValueRequested": false,
+                            "nodeType": "IndexAccess",
+                            "src": "36361:19:1",
+                            "typeDescriptions": {
+                              "typeIdentifier": "t_string_storage",
+                              "typeString": "string storage ref"
+                            }
+                          }
+                        ],
+                        "expression": {
+                          "argumentTypes": [
+                            {
+                              "typeIdentifier": "t_string_storage",
+                              "typeString": "string storage ref"
+                            }
+                          ],
+                          "id": 1431,
+                          "isConstant": false,
+                          "isLValue": false,
+                          "isPure": true,
+                          "lValueRequested": false,
+                          "nodeType": "ElementaryTypeNameExpression",
+                          "src": "36355:5:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_type$_t_bytes_storage_ptr_$",
+                            "typeString": "type(bytes storage pointer)"
+                          },
+                          "typeName": "bytes"
+                        },
+                        "id": 1435,
+                        "isConstant": false,
+                        "isLValue": false,
+                        "isPure": false,
+                        "kind": "typeConversion",
+                        "lValueRequested": false,
+                        "names": [],
+                        "nodeType": "FunctionCall",
+                        "src": "36355:26:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_bytes_storage_ptr",
+                          "typeString": "bytes storage pointer"
+                        }
+                      },
+                      "id": 1436,
+                      "isConstant": false,
+                      "isLValue": true,
+                      "isPure": false,
+                      "lValueRequested": false,
+                      "memberName": "length",
+                      "nodeType": "MemberAccess",
+                      "referencedDeclaration": null,
+                      "src": "36355:33:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_uint256",
+                        "typeString": "uint256"
+                      }
+                    },
+                    "nodeType": "BinaryOperation",
+                    "operator": "!=",
+                    "rightExpression": {
+                      "argumentTypes": null,
+                      "hexValue": "30",
+                      "id": 1437,
+                      "isConstant": false,
+                      "isLValue": false,
+                      "isPure": true,
+                      "kind": "number",
+                      "lValueRequested": false,
+                      "nodeType": "Literal",
+                      "src": "36392:1:1",
+                      "subdenomination": null,
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_rational_0_by_1",
+                        "typeString": "int_const 0"
+                      },
+                      "value": "0"
+                    },
+                    "src": "36355:38:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_bool",
+                      "typeString": "bool"
+                    }
+                  },
+                  "falseBody": null,
+                  "id": 1445,
+                  "nodeType": "IfStatement",
+                  "src": "36351:95:1",
+                  "trueBody": {
+                    "id": 1444,
+                    "nodeType": "Block",
+                    "src": "36395:51:1",
+                    "statements": [
+                      {
+                        "expression": {
+                          "argumentTypes": null,
+                          "id": 1442,
+                          "isConstant": false,
+                          "isLValue": false,
+                          "isPure": false,
+                          "lValueRequested": false,
+                          "nodeType": "UnaryOperation",
+                          "operator": "delete",
+                          "prefix": true,
+                          "src": "36409:26:1",
+                          "subExpression": {
+                            "argumentTypes": null,
+                            "baseExpression": {
+                              "argumentTypes": null,
+                              "id": 1439,
+                              "name": "_tokenURIs",
+                              "nodeType": "Identifier",
+                              "overloadedDeclarations": [],
+                              "referencedDeclaration": 1338,
+                              "src": "36416:10:1",
+                              "typeDescriptions": {
+                                "typeIdentifier": "t_mapping$_t_uint256_$_t_string_storage_$",
+                                "typeString": "mapping(uint256 => string storage ref)"
+                              }
+                            },
+                            "id": 1441,
+                            "indexExpression": {
+                              "argumentTypes": null,
+                              "id": 1440,
+                              "name": "tokenId",
+                              "nodeType": "Identifier",
+                              "overloadedDeclarations": [],
+                              "referencedDeclaration": 1421,
+                              "src": "36427:7:1",
+                              "typeDescriptions": {
+                                "typeIdentifier": "t_uint256",
+                                "typeString": "uint256"
+                              }
+                            },
+                            "isConstant": false,
+                            "isLValue": true,
+                            "isPure": false,
+                            "lValueRequested": true,
+                            "nodeType": "IndexAccess",
+                            "src": "36416:19:1",
+                            "typeDescriptions": {
+                              "typeIdentifier": "t_string_storage",
+                              "typeString": "string storage ref"
+                            }
+                          },
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_tuple$__$",
+                            "typeString": "tuple()"
+                          }
+                        },
+                        "id": 1443,
+                        "nodeType": "ExpressionStatement",
+                        "src": "36409:26:1"
+                      }
+                    ]
+                  }
+                }
+              ]
+            },
+            "documentation": "@dev Internal function to burn a specific token.\nReverts if the token does not exist.\nDeprecated, use _burn(uint256) instead.\n@param owner owner of the token to burn\n@param tokenId uint256 ID of the token being burned by the msg.sender",
+            "id": 1447,
+            "implemented": true,
+            "kind": "function",
+            "modifiers": [],
+            "name": "_burn",
+            "nodeType": "FunctionDefinition",
+            "parameters": {
+              "id": 1422,
+              "nodeType": "ParameterList",
+              "parameters": [
+                {
+                  "constant": false,
+                  "id": 1419,
+                  "name": "owner",
+                  "nodeType": "VariableDeclaration",
+                  "scope": 1447,
+                  "src": "36227:13:1",
+                  "stateVariable": false,
+                  "storageLocation": "default",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_address",
+                    "typeString": "address"
+                  },
+                  "typeName": {
+                    "id": 1418,
+                    "name": "address",
+                    "nodeType": "ElementaryTypeName",
+                    "src": "36227:7:1",
+                    "stateMutability": "nonpayable",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_address",
+                      "typeString": "address"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                },
+                {
+                  "constant": false,
+                  "id": 1421,
+                  "name": "tokenId",
+                  "nodeType": "VariableDeclaration",
+                  "scope": 1447,
+                  "src": "36242:15:1",
+                  "stateVariable": false,
+                  "storageLocation": "default",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_uint256",
+                    "typeString": "uint256"
+                  },
+                  "typeName": {
+                    "id": 1420,
+                    "name": "uint256",
+                    "nodeType": "ElementaryTypeName",
+                    "src": "36242:7:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_uint256",
+                      "typeString": "uint256"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                }
+              ],
+              "src": "36226:32:1"
+            },
+            "returnParameters": {
+              "id": 1423,
+              "nodeType": "ParameterList",
+              "parameters": [],
+              "src": "36268:0:1"
+            },
+            "scope": 1448,
+            "src": "36212:240:1",
+            "stateMutability": "nonpayable",
+            "superFunction": 811,
+            "visibility": "internal"
+          }
+        ],
+        "scope": 1469,
+        "src": "33817:2637:1"
+      },
+      {
+        "id": 1449,
+        "literals": [
+          "solidity",
+          "^",
+          "0.5",
+          ".0"
+        ],
+        "nodeType": "PragmaDirective",
+        "src": "36518:23:1"
+      },
+      {
+        "baseContracts": [
+          {
+            "arguments": null,
+            "baseName": {
+              "contractScope": null,
+              "id": 1450,
+              "name": "ERC721",
+              "nodeType": "UserDefinedTypeName",
+              "referencedDeclaration": 944,
+              "src": "36838:6:1",
+              "typeDescriptions": {
+                "typeIdentifier": "t_contract$_ERC721_$944",
+                "typeString": "contract ERC721"
+              }
+            },
+            "id": 1451,
+            "nodeType": "InheritanceSpecifier",
+            "src": "36838:6:1"
+          },
+          {
+            "arguments": null,
+            "baseName": {
+              "contractScope": null,
+              "id": 1452,
+              "name": "ERC721Enumerable",
+              "nodeType": "UserDefinedTypeName",
+              "referencedDeclaration": 1302,
+              "src": "36846:16:1",
+              "typeDescriptions": {
+                "typeIdentifier": "t_contract$_ERC721Enumerable_$1302",
+                "typeString": "contract ERC721Enumerable"
+              }
+            },
+            "id": 1453,
+            "nodeType": "InheritanceSpecifier",
+            "src": "36846:16:1"
+          },
+          {
+            "arguments": null,
+            "baseName": {
+              "contractScope": null,
+              "id": 1454,
+              "name": "ERC721Metadata",
+              "nodeType": "UserDefinedTypeName",
+              "referencedDeclaration": 1448,
+              "src": "36864:14:1",
+              "typeDescriptions": {
+                "typeIdentifier": "t_contract$_ERC721Metadata_$1448",
+                "typeString": "contract ERC721Metadata"
+              }
+            },
+            "id": 1455,
+            "nodeType": "InheritanceSpecifier",
+            "src": "36864:14:1"
+          }
+        ],
+        "contractDependencies": [
+          944,
+          969,
+          23,
+          124,
+          386,
+          1302,
+          1323,
+          1448
+        ],
+        "contractKind": "contract",
+        "documentation": "@title Full ERC721 Token\nThis implementation includes all the required and some optional functionality of the ERC721 standard\nMoreover, it includes approve all functionality using operator terminology\n@dev see https://eips.ethereum.org/EIPS/eip-721",
+        "fullyImplemented": true,
+        "id": 1468,
+        "linearizedBaseContracts": [
+          1468,
+          1448,
+          1323,
+          1302,
+          969,
+          944,
+          124,
+          386,
+          23
+        ],
+        "name": "ERC721Full",
+        "nodeType": "ContractDefinition",
+        "nodes": [
+          {
+            "body": {
+              "id": 1466,
+              "nodeType": "Block",
+              "src": "36976:64:1",
+              "statements": []
+            },
+            "documentation": null,
+            "id": 1467,
+            "implemented": true,
+            "kind": "constructor",
+            "modifiers": [
+              {
+                "arguments": [
+                  {
+                    "argumentTypes": null,
+                    "id": 1462,
+                    "name": "name",
+                    "nodeType": "Identifier",
+                    "overloadedDeclarations": [],
+                    "referencedDeclaration": 1457,
+                    "src": "36962:4:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_string_memory_ptr",
+                      "typeString": "string memory"
+                    }
+                  },
+                  {
+                    "argumentTypes": null,
+                    "id": 1463,
+                    "name": "symbol",
+                    "nodeType": "Identifier",
+                    "overloadedDeclarations": [],
+                    "referencedDeclaration": 1459,
+                    "src": "36968:6:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_string_memory_ptr",
+                      "typeString": "string memory"
+                    }
+                  }
+                ],
+                "id": 1464,
+                "modifierName": {
+                  "argumentTypes": null,
+                  "id": 1461,
+                  "name": "ERC721Metadata",
+                  "nodeType": "Identifier",
+                  "overloadedDeclarations": [],
+                  "referencedDeclaration": 1448,
+                  "src": "36947:14:1",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_type$_t_contract$_ERC721Metadata_$1448_$",
+                    "typeString": "type(contract ERC721Metadata)"
+                  }
+                },
+                "nodeType": "ModifierInvocation",
+                "src": "36947:28:1"
+              }
+            ],
+            "name": "",
+            "nodeType": "FunctionDefinition",
+            "parameters": {
+              "id": 1460,
+              "nodeType": "ParameterList",
+              "parameters": [
+                {
+                  "constant": false,
+                  "id": 1457,
+                  "name": "name",
+                  "nodeType": "VariableDeclaration",
+                  "scope": 1467,
+                  "src": "36898:18:1",
+                  "stateVariable": false,
+                  "storageLocation": "memory",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_string_memory_ptr",
+                    "typeString": "string"
+                  },
+                  "typeName": {
+                    "id": 1456,
+                    "name": "string",
+                    "nodeType": "ElementaryTypeName",
+                    "src": "36898:6:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_string_storage_ptr",
+                      "typeString": "string"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                },
+                {
+                  "constant": false,
+                  "id": 1459,
+                  "name": "symbol",
+                  "nodeType": "VariableDeclaration",
+                  "scope": 1467,
+                  "src": "36918:20:1",
+                  "stateVariable": false,
+                  "storageLocation": "memory",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_string_memory_ptr",
+                    "typeString": "string"
+                  },
+                  "typeName": {
+                    "id": 1458,
+                    "name": "string",
+                    "nodeType": "ElementaryTypeName",
+                    "src": "36918:6:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_string_storage_ptr",
+                      "typeString": "string"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                }
+              ],
+              "src": "36897:42:1"
+            },
+            "returnParameters": {
+              "id": 1465,
+              "nodeType": "ParameterList",
+              "parameters": [],
+              "src": "36976:0:1"
+            },
+            "scope": 1468,
+            "src": "36885:155:1",
+            "stateMutability": "nonpayable",
+            "superFunction": null,
+            "visibility": "public"
+          }
+        ],
+        "scope": 1469,
+        "src": "36815:227:1"
+      }
+    ],
+    "src": "61:36982:1"
+  },
+  "compiler": {
+    "name": "solc",
+    "version": "0.5.0+commit.1d4f565a.Emscripten.clang"
+  },
+  "networks": {},
+  "schemaVersion": "3.0.2",
+  "updatedAt": "2019-09-05T15:01:08.708Z",
+  "devdoc": {
+    "details": "Interface of the ERC165 standard, as defined in the [EIP](https://eips.ethereum.org/EIPS/eip-165). * Implementers can declare support of contract interfaces, which can then be queried by others (`ERC165Checker`). * For an implementation, see `ERC165`.",
+    "methods": {
+      "supportsInterface(bytes4)": {
+        "details": "Returns true if this contract implements the interface defined by `interfaceId`. See the corresponding [EIP section](https://eips.ethereum.org/EIPS/eip-165#how-interfaces-are-identified) to learn more about how these ids are created.     * This function call must use less than 30 000 gas."
+      }
+    }
+  },
+  "userdoc": {
+    "methods": {}
+  }
+}
\ No newline at end of file
diff --git a/src/abis/IERC721.json b/src/abis/IERC721.json
new file mode 100644
index 0000000..8c8d68b
--- /dev/null
+++ b/src/abis/IERC721.json
@@ -0,0 +1,37736 @@
+{
+  "contractName": "IERC721",
+  "abi": [
+    {
+      "constant": true,
+      "inputs": [
+        {
+          "name": "interfaceId",
+          "type": "bytes4"
+        }
+      ],
+      "name": "supportsInterface",
+      "outputs": [
+        {
+          "name": "",
+          "type": "bool"
+        }
+      ],
+      "payable": false,
+      "stateMutability": "view",
+      "type": "function"
+    },
+    {
+      "anonymous": false,
+      "inputs": [
+        {
+          "indexed": true,
+          "name": "from",
+          "type": "address"
+        },
+        {
+          "indexed": true,
+          "name": "to",
+          "type": "address"
+        },
+        {
+          "indexed": true,
+          "name": "tokenId",
+          "type": "uint256"
+        }
+      ],
+      "name": "Transfer",
+      "type": "event"
+    },
+    {
+      "anonymous": false,
+      "inputs": [
+        {
+          "indexed": true,
+          "name": "owner",
+          "type": "address"
+        },
+        {
+          "indexed": true,
+          "name": "approved",
+          "type": "address"
+        },
+        {
+          "indexed": true,
+          "name": "tokenId",
+          "type": "uint256"
+        }
+      ],
+      "name": "Approval",
+      "type": "event"
+    },
+    {
+      "anonymous": false,
+      "inputs": [
+        {
+          "indexed": true,
+          "name": "owner",
+          "type": "address"
+        },
+        {
+          "indexed": true,
+          "name": "operator",
+          "type": "address"
+        },
+        {
+          "indexed": false,
+          "name": "approved",
+          "type": "bool"
+        }
+      ],
+      "name": "ApprovalForAll",
+      "type": "event"
+    },
+    {
+      "constant": true,
+      "inputs": [
+        {
+          "name": "owner",
+          "type": "address"
+        }
+      ],
+      "name": "balanceOf",
+      "outputs": [
+        {
+          "name": "balance",
+          "type": "uint256"
+        }
+      ],
+      "payable": false,
+      "stateMutability": "view",
+      "type": "function"
+    },
+    {
+      "constant": true,
+      "inputs": [
+        {
+          "name": "tokenId",
+          "type": "uint256"
+        }
+      ],
+      "name": "ownerOf",
+      "outputs": [
+        {
+          "name": "owner",
+          "type": "address"
+        }
+      ],
+      "payable": false,
+      "stateMutability": "view",
+      "type": "function"
+    },
+    {
+      "constant": false,
+      "inputs": [
+        {
+          "name": "from",
+          "type": "address"
+        },
+        {
+          "name": "to",
+          "type": "address"
+        },
+        {
+          "name": "tokenId",
+          "type": "uint256"
+        }
+      ],
+      "name": "transferFrom",
+      "outputs": [],
+      "payable": false,
+      "stateMutability": "nonpayable",
+      "type": "function"
+    },
+    {
+      "constant": false,
+      "inputs": [
+        {
+          "name": "to",
+          "type": "address"
+        },
+        {
+          "name": "tokenId",
+          "type": "uint256"
+        }
+      ],
+      "name": "approve",
+      "outputs": [],
+      "payable": false,
+      "stateMutability": "nonpayable",
+      "type": "function"
+    },
+    {
+      "constant": true,
+      "inputs": [
+        {
+          "name": "tokenId",
+          "type": "uint256"
+        }
+      ],
+      "name": "getApproved",
+      "outputs": [
+        {
+          "name": "operator",
+          "type": "address"
+        }
+      ],
+      "payable": false,
+      "stateMutability": "view",
+      "type": "function"
+    },
+    {
+      "constant": false,
+      "inputs": [
+        {
+          "name": "operator",
+          "type": "address"
+        },
+        {
+          "name": "_approved",
+          "type": "bool"
+        }
+      ],
+      "name": "setApprovalForAll",
+      "outputs": [],
+      "payable": false,
+      "stateMutability": "nonpayable",
+      "type": "function"
+    },
+    {
+      "constant": true,
+      "inputs": [
+        {
+          "name": "owner",
+          "type": "address"
+        },
+        {
+          "name": "operator",
+          "type": "address"
+        }
+      ],
+      "name": "isApprovedForAll",
+      "outputs": [
+        {
+          "name": "",
+          "type": "bool"
+        }
+      ],
+      "payable": false,
+      "stateMutability": "view",
+      "type": "function"
+    },
+    {
+      "constant": false,
+      "inputs": [
+        {
+          "name": "from",
+          "type": "address"
+        },
+        {
+          "name": "to",
+          "type": "address"
+        },
+        {
+          "name": "tokenId",
+          "type": "uint256"
+        }
+      ],
+      "name": "safeTransferFrom",
+      "outputs": [],
+      "payable": false,
+      "stateMutability": "nonpayable",
+      "type": "function"
+    },
+    {
+      "constant": false,
+      "inputs": [
+        {
+          "name": "from",
+          "type": "address"
+        },
+        {
+          "name": "to",
+          "type": "address"
+        },
+        {
+          "name": "tokenId",
+          "type": "uint256"
+        },
+        {
+          "name": "data",
+          "type": "bytes"
+        }
+      ],
+      "name": "safeTransferFrom",
+      "outputs": [],
+      "payable": false,
+      "stateMutability": "nonpayable",
+      "type": "function"
+    }
+  ],
+  "bytecode": "0x",
+  "deployedBytecode": "0x",
+  "sourceMap": "",
+  "deployedSourceMap": "",
+  "source": "\n// File: @openzeppelin/contracts/introspection/IERC165.sol\n\npragma solidity ^0.5.0;\n\n/**\n * @dev Interface of the ERC165 standard, as defined in the\n * [EIP](https://eips.ethereum.org/EIPS/eip-165).\n *\n * Implementers can declare support of contract interfaces, which can then be\n * queried by others (`ERC165Checker`).\n *\n * For an implementation, see `ERC165`.\n */\ninterface IERC165 {\n    /**\n     * @dev Returns true if this contract implements the interface defined by\n     * `interfaceId`. See the corresponding\n     * [EIP section](https://eips.ethereum.org/EIPS/eip-165#how-interfaces-are-identified)\n     * to learn more about how these ids are created.\n     *\n     * This function call must use less than 30 000 gas.\n     */\n    function supportsInterface(bytes4 interfaceId) external view returns (bool);\n}\n\n// File: @openzeppelin/contracts/token/ERC721/IERC721.sol\n\npragma solidity ^0.5.0;\n\n\n/**\n * @dev Required interface of an ERC721 compliant contract.\n */\ncontract IERC721 is IERC165 {\n    event Transfer(address indexed from, address indexed to, uint256 indexed tokenId);\n    event Approval(address indexed owner, address indexed approved, uint256 indexed tokenId);\n    event ApprovalForAll(address indexed owner, address indexed operator, bool approved);\n\n    /**\n     * @dev Returns the number of NFTs in `owner`'s account.\n     */\n    function balanceOf(address owner) public view returns (uint256 balance);\n\n    /**\n     * @dev Returns the owner of the NFT specified by `tokenId`.\n     */\n    function ownerOf(uint256 tokenId) public view returns (address owner);\n\n    /**\n     * @dev Transfers a specific NFT (`tokenId`) from one account (`from`) to\n     * another (`to`).\n     *\n     * \n     *\n     * Requirements:\n     * - `from`, `to` cannot be zero.\n     * - `tokenId` must be owned by `from`.\n     * - If the caller is not `from`, it must be have been allowed to move this\n     * NFT by either `approve` or `setApproveForAll`.\n     */\n    function safeTransferFrom(address from, address to, uint256 tokenId) public;\n    /**\n     * @dev Transfers a specific NFT (`tokenId`) from one account (`from`) to\n     * another (`to`).\n     *\n     * Requirements:\n     * - If the caller is not `from`, it must be approved to move this NFT by\n     * either `approve` or `setApproveForAll`.\n     */\n    function transferFrom(address from, address to, uint256 tokenId) public;\n    function approve(address to, uint256 tokenId) public;\n    function getApproved(uint256 tokenId) public view returns (address operator);\n\n    function setApprovalForAll(address operator, bool _approved) public;\n    function isApprovedForAll(address owner, address operator) public view returns (bool);\n\n\n    function safeTransferFrom(address from, address to, uint256 tokenId, bytes memory data) public;\n}\n\n// File: @openzeppelin/contracts/token/ERC721/IERC721Receiver.sol\n\npragma solidity ^0.5.0;\n\n/**\n * @title ERC721 token receiver interface\n * @dev Interface for any contract that wants to support safeTransfers\n * from ERC721 asset contracts.\n */\ncontract IERC721Receiver {\n    /**\n     * @notice Handle the receipt of an NFT\n     * @dev The ERC721 smart contract calls this function on the recipient\n     * after a `safeTransfer`. This function MUST return the function selector,\n     * otherwise the caller will revert the transaction. The selector to be\n     * returned can be obtained as `this.onERC721Received.selector`. This\n     * function MAY throw to revert and reject the transfer.\n     * Note: the ERC721 contract address is always the message sender.\n     * @param operator The address which called `safeTransferFrom` function\n     * @param from The address which previously owned the token\n     * @param tokenId The NFT identifier which is being transferred\n     * @param data Additional data with no specified format\n     * @return bytes4 `bytes4(keccak256(\"onERC721Received(address,address,uint256,bytes)\"))`\n     */\n    function onERC721Received(address operator, address from, uint256 tokenId, bytes memory data)\n    public returns (bytes4);\n}\n\n// File: @openzeppelin/contracts/math/SafeMath.sol\n\npragma solidity ^0.5.0;\n\n/**\n * @dev Wrappers over Solidity's arithmetic operations with added overflow\n * checks.\n *\n * Arithmetic operations in Solidity wrap on overflow. This can easily result\n * in bugs, because programmers usually assume that an overflow raises an\n * error, which is the standard behavior in high level programming languages.\n * `SafeMath` restores this intuition by reverting the transaction when an\n * operation overflows.\n *\n * Using this library instead of the unchecked operations eliminates an entire\n * class of bugs, so it's recommended to use it always.\n */\nlibrary SafeMath {\n    /**\n     * @dev Returns the addition of two unsigned integers, reverting on\n     * overflow.\n     *\n     * Counterpart to Solidity's `+` operator.\n     *\n     * Requirements:\n     * - Addition cannot overflow.\n     */\n    function add(uint256 a, uint256 b) internal pure returns (uint256) {\n        uint256 c = a + b;\n        require(c >= a, \"SafeMath: addition overflow\");\n\n        return c;\n    }\n\n    /**\n     * @dev Returns the subtraction of two unsigned integers, reverting on\n     * overflow (when the result is negative).\n     *\n     * Counterpart to Solidity's `-` operator.\n     *\n     * Requirements:\n     * - Subtraction cannot overflow.\n     */\n    function sub(uint256 a, uint256 b) internal pure returns (uint256) {\n        require(b <= a, \"SafeMath: subtraction overflow\");\n        uint256 c = a - b;\n\n        return c;\n    }\n\n    /**\n     * @dev Returns the multiplication of two unsigned integers, reverting on\n     * overflow.\n     *\n     * Counterpart to Solidity's `*` operator.\n     *\n     * Requirements:\n     * - Multiplication cannot overflow.\n     */\n    function mul(uint256 a, uint256 b) internal pure returns (uint256) {\n        // Gas optimization: this is cheaper than requiring 'a' not being zero, but the\n        // benefit is lost if 'b' is also tested.\n        // See: https://github.com/OpenZeppelin/openzeppelin-contracts/pull/522\n        if (a == 0) {\n            return 0;\n        }\n\n        uint256 c = a * b;\n        require(c / a == b, \"SafeMath: multiplication overflow\");\n\n        return c;\n    }\n\n    /**\n     * @dev Returns the integer division of two unsigned integers. Reverts on\n     * division by zero. The result is rounded towards zero.\n     *\n     * Counterpart to Solidity's `/` operator. Note: this function uses a\n     * `revert` opcode (which leaves remaining gas untouched) while Solidity\n     * uses an invalid opcode to revert (consuming all remaining gas).\n     *\n     * Requirements:\n     * - The divisor cannot be zero.\n     */\n    function div(uint256 a, uint256 b) internal pure returns (uint256) {\n        // Solidity only automatically asserts when dividing by 0\n        require(b > 0, \"SafeMath: division by zero\");\n        uint256 c = a / b;\n        // assert(a == b * c + a % b); // There is no case in which this doesn't hold\n\n        return c;\n    }\n\n    /**\n     * @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo),\n     * Reverts when dividing by zero.\n     *\n     * Counterpart to Solidity's `%` operator. This function uses a `revert`\n     * opcode (which leaves remaining gas untouched) while Solidity uses an\n     * invalid opcode to revert (consuming all remaining gas).\n     *\n     * Requirements:\n     * - The divisor cannot be zero.\n     */\n    function mod(uint256 a, uint256 b) internal pure returns (uint256) {\n        require(b != 0, \"SafeMath: modulo by zero\");\n        return a % b;\n    }\n}\n\n// File: @openzeppelin/contracts/utils/Address.sol\n\npragma solidity ^0.5.0;\n\n/**\n * @dev Collection of functions related to the address type,\n */\nlibrary Address {\n    /**\n     * @dev Returns true if `account` is a contract.\n     *\n     * This test is non-exhaustive, and there may be false-negatives: during the\n     * execution of a contract's constructor, its address will be reported as\n     * not containing a contract.\n     *\n     * > It is unsafe to assume that an address for which this function returns\n     * false is an externally-owned account (EOA) and not a contract.\n     */\n    function isContract(address account) internal view returns (bool) {\n        // This method relies in extcodesize, which returns 0 for contracts in\n        // construction, since the code is only stored at the end of the\n        // constructor execution.\n\n        uint256 size;\n        // solhint-disable-next-line no-inline-assembly\n        assembly { size := extcodesize(account) }\n        return size > 0;\n    }\n}\n\n// File: @openzeppelin/contracts/drafts/Counters.sol\n\npragma solidity ^0.5.0;\n\n\n/**\n * @title Counters\n * @author Matt Condon (@shrugs)\n * @dev Provides counters that can only be incremented or decremented by one. This can be used e.g. to track the number\n * of elements in a mapping, issuing ERC721 ids, or counting request ids.\n *\n * Include with `using Counters for Counters.Counter;`\n * Since it is not possible to overflow a 256 bit integer with increments of one, `increment` can skip the SafeMath\n * overflow check, thereby saving gas. This does assume however correct usage, in that the underlying `_value` is never\n * directly accessed.\n */\nlibrary Counters {\n    using SafeMath for uint256;\n\n    struct Counter {\n        // This variable should never be directly accessed by users of the library: interactions must be restricted to\n        // the library's function. As of Solidity v0.5.2, this cannot be enforced, though there is a proposal to add\n        // this feature: see https://github.com/ethereum/solidity/issues/4637\n        uint256 _value; // default: 0\n    }\n\n    function current(Counter storage counter) internal view returns (uint256) {\n        return counter._value;\n    }\n\n    function increment(Counter storage counter) internal {\n        counter._value += 1;\n    }\n\n    function decrement(Counter storage counter) internal {\n        counter._value = counter._value.sub(1);\n    }\n}\n\n// File: @openzeppelin/contracts/introspection/ERC165.sol\n\npragma solidity ^0.5.0;\n\n\n/**\n * @dev Implementation of the `IERC165` interface.\n *\n * Contracts may inherit from this and call `_registerInterface` to declare\n * their support of an interface.\n */\ncontract ERC165 is IERC165 {\n    /*\n     * bytes4(keccak256('supportsInterface(bytes4)')) == 0x01ffc9a7\n     */\n    bytes4 private constant _INTERFACE_ID_ERC165 = 0x01ffc9a7;\n\n    /**\n     * @dev Mapping of interface ids to whether or not it's supported.\n     */\n    mapping(bytes4 => bool) private _supportedInterfaces;\n\n    constructor () internal {\n        // Derived contracts need only register support for their own interfaces,\n        // we register support for ERC165 itself here\n        _registerInterface(_INTERFACE_ID_ERC165);\n    }\n\n    /**\n     * @dev See `IERC165.supportsInterface`.\n     *\n     * Time complexity O(1), guaranteed to always use less than 30 000 gas.\n     */\n    function supportsInterface(bytes4 interfaceId) external view returns (bool) {\n        return _supportedInterfaces[interfaceId];\n    }\n\n    /**\n     * @dev Registers the contract as an implementer of the interface defined by\n     * `interfaceId`. Support of the actual ERC165 interface is automatic and\n     * registering its interface id is not required.\n     *\n     * See `IERC165.supportsInterface`.\n     *\n     * Requirements:\n     *\n     * - `interfaceId` cannot be the ERC165 invalid interface (`0xffffffff`).\n     */\n    function _registerInterface(bytes4 interfaceId) internal {\n        require(interfaceId != 0xffffffff, \"ERC165: invalid interface id\");\n        _supportedInterfaces[interfaceId] = true;\n    }\n}\n\n// File: @openzeppelin/contracts/token/ERC721/ERC721.sol\n\npragma solidity ^0.5.0;\n\n\n\n\n\n\n\n/**\n * @title ERC721 Non-Fungible Token Standard basic implementation\n * @dev see https://eips.ethereum.org/EIPS/eip-721\n */\ncontract ERC721 is ERC165, IERC721 {\n    using SafeMath for uint256;\n    using Address for address;\n    using Counters for Counters.Counter;\n\n    // Equals to `bytes4(keccak256(\"onERC721Received(address,address,uint256,bytes)\"))`\n    // which can be also obtained as `IERC721Receiver(0).onERC721Received.selector`\n    bytes4 private constant _ERC721_RECEIVED = 0x150b7a02;\n\n    // Mapping from token ID to owner\n    mapping (uint256 => address) private _tokenOwner;\n\n    // Mapping from token ID to approved address\n    mapping (uint256 => address) private _tokenApprovals;\n\n    // Mapping from owner to number of owned token\n    mapping (address => Counters.Counter) private _ownedTokensCount;\n\n    // Mapping from owner to operator approvals\n    mapping (address => mapping (address => bool)) private _operatorApprovals;\n\n    /*\n     *     bytes4(keccak256('balanceOf(address)')) == 0x70a08231\n     *     bytes4(keccak256('ownerOf(uint256)')) == 0x6352211e\n     *     bytes4(keccak256('approve(address,uint256)')) == 0x095ea7b3\n     *     bytes4(keccak256('getApproved(uint256)')) == 0x081812fc\n     *     bytes4(keccak256('setApprovalForAll(address,bool)')) == 0xa22cb465\n     *     bytes4(keccak256('isApprovedForAll(address,address)')) == 0xe985e9c\n     *     bytes4(keccak256('transferFrom(address,address,uint256)')) == 0x23b872dd\n     *     bytes4(keccak256('safeTransferFrom(address,address,uint256)')) == 0x42842e0e\n     *     bytes4(keccak256('safeTransferFrom(address,address,uint256,bytes)')) == 0xb88d4fde\n     *\n     *     => 0x70a08231 ^ 0x6352211e ^ 0x095ea7b3 ^ 0x081812fc ^\n     *        0xa22cb465 ^ 0xe985e9c ^ 0x23b872dd ^ 0x42842e0e ^ 0xb88d4fde == 0x80ac58cd\n     */\n    bytes4 private constant _INTERFACE_ID_ERC721 = 0x80ac58cd;\n\n    constructor () public {\n        // register the supported interfaces to conform to ERC721 via ERC165\n        _registerInterface(_INTERFACE_ID_ERC721);\n    }\n\n    /**\n     * @dev Gets the balance of the specified address.\n     * @param owner address to query the balance of\n     * @return uint256 representing the amount owned by the passed address\n     */\n    function balanceOf(address owner) public view returns (uint256) {\n        require(owner != address(0), \"ERC721: balance query for the zero address\");\n\n        return _ownedTokensCount[owner].current();\n    }\n\n    /**\n     * @dev Gets the owner of the specified token ID.\n     * @param tokenId uint256 ID of the token to query the owner of\n     * @return address currently marked as the owner of the given token ID\n     */\n    function ownerOf(uint256 tokenId) public view returns (address) {\n        address owner = _tokenOwner[tokenId];\n        require(owner != address(0), \"ERC721: owner query for nonexistent token\");\n\n        return owner;\n    }\n\n    /**\n     * @dev Approves another address to transfer the given token ID\n     * The zero address indicates there is no approved address.\n     * There can only be one approved address per token at a given time.\n     * Can only be called by the token owner or an approved operator.\n     * @param to address to be approved for the given token ID\n     * @param tokenId uint256 ID of the token to be approved\n     */\n    function approve(address to, uint256 tokenId) public {\n        address owner = ownerOf(tokenId);\n        require(to != owner, \"ERC721: approval to current owner\");\n\n        require(msg.sender == owner || isApprovedForAll(owner, msg.sender),\n            \"ERC721: approve caller is not owner nor approved for all\"\n        );\n\n        _tokenApprovals[tokenId] = to;\n        emit Approval(owner, to, tokenId);\n    }\n\n    /**\n     * @dev Gets the approved address for a token ID, or zero if no address set\n     * Reverts if the token ID does not exist.\n     * @param tokenId uint256 ID of the token to query the approval of\n     * @return address currently approved for the given token ID\n     */\n    function getApproved(uint256 tokenId) public view returns (address) {\n        require(_exists(tokenId), \"ERC721: approved query for nonexistent token\");\n\n        return _tokenApprovals[tokenId];\n    }\n\n    /**\n     * @dev Sets or unsets the approval of a given operator\n     * An operator is allowed to transfer all tokens of the sender on their behalf.\n     * @param to operator address to set the approval\n     * @param approved representing the status of the approval to be set\n     */\n    function setApprovalForAll(address to, bool approved) public {\n        require(to != msg.sender, \"ERC721: approve to caller\");\n\n        _operatorApprovals[msg.sender][to] = approved;\n        emit ApprovalForAll(msg.sender, to, approved);\n    }\n\n    /**\n     * @dev Tells whether an operator is approved by a given owner.\n     * @param owner owner address which you want to query the approval of\n     * @param operator operator address which you want to query the approval of\n     * @return bool whether the given operator is approved by the given owner\n     */\n    function isApprovedForAll(address owner, address operator) public view returns (bool) {\n        return _operatorApprovals[owner][operator];\n    }\n\n    /**\n     * @dev Transfers the ownership of a given token ID to another address.\n     * Usage of this method is discouraged, use `safeTransferFrom` whenever possible.\n     * Requires the msg.sender to be the owner, approved, or operator.\n     * @param from current owner of the token\n     * @param to address to receive the ownership of the given token ID\n     * @param tokenId uint256 ID of the token to be transferred\n     */\n    function transferFrom(address from, address to, uint256 tokenId) public {\n        //solhint-disable-next-line max-line-length\n        require(_isApprovedOrOwner(msg.sender, tokenId), \"ERC721: transfer caller is not owner nor approved\");\n\n        _transferFrom(from, to, tokenId);\n    }\n\n    /**\n     * @dev Safely transfers the ownership of a given token ID to another address\n     * If the target address is a contract, it must implement `onERC721Received`,\n     * which is called upon a safe transfer, and return the magic value\n     * `bytes4(keccak256(\"onERC721Received(address,address,uint256,bytes)\"))`; otherwise,\n     * the transfer is reverted.\n     * Requires the msg.sender to be the owner, approved, or operator\n     * @param from current owner of the token\n     * @param to address to receive the ownership of the given token ID\n     * @param tokenId uint256 ID of the token to be transferred\n     */\n    function safeTransferFrom(address from, address to, uint256 tokenId) public {\n        safeTransferFrom(from, to, tokenId, \"\");\n    }\n\n    /**\n     * @dev Safely transfers the ownership of a given token ID to another address\n     * If the target address is a contract, it must implement `onERC721Received`,\n     * which is called upon a safe transfer, and return the magic value\n     * `bytes4(keccak256(\"onERC721Received(address,address,uint256,bytes)\"))`; otherwise,\n     * the transfer is reverted.\n     * Requires the msg.sender to be the owner, approved, or operator\n     * @param from current owner of the token\n     * @param to address to receive the ownership of the given token ID\n     * @param tokenId uint256 ID of the token to be transferred\n     * @param _data bytes data to send along with a safe transfer check\n     */\n    function safeTransferFrom(address from, address to, uint256 tokenId, bytes memory _data) public {\n        transferFrom(from, to, tokenId);\n        require(_checkOnERC721Received(from, to, tokenId, _data), \"ERC721: transfer to non ERC721Receiver implementer\");\n    }\n\n    /**\n     * @dev Returns whether the specified token exists.\n     * @param tokenId uint256 ID of the token to query the existence of\n     * @return bool whether the token exists\n     */\n    function _exists(uint256 tokenId) internal view returns (bool) {\n        address owner = _tokenOwner[tokenId];\n        return owner != address(0);\n    }\n\n    /**\n     * @dev Returns whether the given spender can transfer a given token ID.\n     * @param spender address of the spender to query\n     * @param tokenId uint256 ID of the token to be transferred\n     * @return bool whether the msg.sender is approved for the given token ID,\n     * is an operator of the owner, or is the owner of the token\n     */\n    function _isApprovedOrOwner(address spender, uint256 tokenId) internal view returns (bool) {\n        require(_exists(tokenId), \"ERC721: operator query for nonexistent token\");\n        address owner = ownerOf(tokenId);\n        return (spender == owner || getApproved(tokenId) == spender || isApprovedForAll(owner, spender));\n    }\n\n    /**\n     * @dev Internal function to mint a new token.\n     * Reverts if the given token ID already exists.\n     * @param to The address that will own the minted token\n     * @param tokenId uint256 ID of the token to be minted\n     */\n    function _mint(address to, uint256 tokenId) internal {\n        require(to != address(0), \"ERC721: mint to the zero address\");\n        require(!_exists(tokenId), \"ERC721: token already minted\");\n\n        _tokenOwner[tokenId] = to;\n        _ownedTokensCount[to].increment();\n\n        emit Transfer(address(0), to, tokenId);\n    }\n\n    /**\n     * @dev Internal function to burn a specific token.\n     * Reverts if the token does not exist.\n     * Deprecated, use _burn(uint256) instead.\n     * @param owner owner of the token to burn\n     * @param tokenId uint256 ID of the token being burned\n     */\n    function _burn(address owner, uint256 tokenId) internal {\n        require(ownerOf(tokenId) == owner, \"ERC721: burn of token that is not own\");\n\n        _clearApproval(tokenId);\n\n        _ownedTokensCount[owner].decrement();\n        _tokenOwner[tokenId] = address(0);\n\n        emit Transfer(owner, address(0), tokenId);\n    }\n\n    /**\n     * @dev Internal function to burn a specific token.\n     * Reverts if the token does not exist.\n     * @param tokenId uint256 ID of the token being burned\n     */\n    function _burn(uint256 tokenId) internal {\n        _burn(ownerOf(tokenId), tokenId);\n    }\n\n    /**\n     * @dev Internal function to transfer ownership of a given token ID to another address.\n     * As opposed to transferFrom, this imposes no restrictions on msg.sender.\n     * @param from current owner of the token\n     * @param to address to receive the ownership of the given token ID\n     * @param tokenId uint256 ID of the token to be transferred\n     */\n    function _transferFrom(address from, address to, uint256 tokenId) internal {\n        require(ownerOf(tokenId) == from, \"ERC721: transfer of token that is not own\");\n        require(to != address(0), \"ERC721: transfer to the zero address\");\n\n        _clearApproval(tokenId);\n\n        _ownedTokensCount[from].decrement();\n        _ownedTokensCount[to].increment();\n\n        _tokenOwner[tokenId] = to;\n\n        emit Transfer(from, to, tokenId);\n    }\n\n    /**\n     * @dev Internal function to invoke `onERC721Received` on a target address.\n     * The call is not executed if the target address is not a contract.\n     *\n     * This function is deprecated.\n     * @param from address representing the previous owner of the given token ID\n     * @param to target address that will receive the tokens\n     * @param tokenId uint256 ID of the token to be transferred\n     * @param _data bytes optional data to send along with the call\n     * @return bool whether the call correctly returned the expected magic value\n     */\n    function _checkOnERC721Received(address from, address to, uint256 tokenId, bytes memory _data)\n        internal returns (bool)\n    {\n        if (!to.isContract()) {\n            return true;\n        }\n\n        bytes4 retval = IERC721Receiver(to).onERC721Received(msg.sender, from, tokenId, _data);\n        return (retval == _ERC721_RECEIVED);\n    }\n\n    /**\n     * @dev Private function to clear current approval of a given token ID.\n     * @param tokenId uint256 ID of the token to be transferred\n     */\n    function _clearApproval(uint256 tokenId) private {\n        if (_tokenApprovals[tokenId] != address(0)) {\n            _tokenApprovals[tokenId] = address(0);\n        }\n    }\n}\n\n// File: @openzeppelin/contracts/token/ERC721/IERC721Enumerable.sol\n\npragma solidity ^0.5.0;\n\n\n/**\n * @title ERC-721 Non-Fungible Token Standard, optional enumeration extension\n * @dev See https://eips.ethereum.org/EIPS/eip-721\n */\ncontract IERC721Enumerable is IERC721 {\n    function totalSupply() public view returns (uint256);\n    function tokenOfOwnerByIndex(address owner, uint256 index) public view returns (uint256 tokenId);\n\n    function tokenByIndex(uint256 index) public view returns (uint256);\n}\n\n// File: @openzeppelin/contracts/token/ERC721/ERC721Enumerable.sol\n\npragma solidity ^0.5.0;\n\n\n\n\n/**\n * @title ERC-721 Non-Fungible Token with optional enumeration extension logic\n * @dev See https://eips.ethereum.org/EIPS/eip-721\n */\ncontract ERC721Enumerable is ERC165, ERC721, IERC721Enumerable {\n    // Mapping from owner to list of owned token IDs\n    mapping(address => uint256[]) private _ownedTokens;\n\n    // Mapping from token ID to index of the owner tokens list\n    mapping(uint256 => uint256) private _ownedTokensIndex;\n\n    // Array with all token ids, used for enumeration\n    uint256[] private _allTokens;\n\n    // Mapping from token id to position in the allTokens array\n    mapping(uint256 => uint256) private _allTokensIndex;\n\n    /*\n     *     bytes4(keccak256('totalSupply()')) == 0x18160ddd\n     *     bytes4(keccak256('tokenOfOwnerByIndex(address,uint256)')) == 0x2f745c59\n     *     bytes4(keccak256('tokenByIndex(uint256)')) == 0x4f6ccce7\n     *\n     *     => 0x18160ddd ^ 0x2f745c59 ^ 0x4f6ccce7 == 0x780e9d63\n     */\n    bytes4 private constant _INTERFACE_ID_ERC721_ENUMERABLE = 0x780e9d63;\n\n    /**\n     * @dev Constructor function.\n     */\n    constructor () public {\n        // register the supported interface to conform to ERC721Enumerable via ERC165\n        _registerInterface(_INTERFACE_ID_ERC721_ENUMERABLE);\n    }\n\n    /**\n     * @dev Gets the token ID at a given index of the tokens list of the requested owner.\n     * @param owner address owning the tokens list to be accessed\n     * @param index uint256 representing the index to be accessed of the requested tokens list\n     * @return uint256 token ID at the given index of the tokens list owned by the requested address\n     */\n    function tokenOfOwnerByIndex(address owner, uint256 index) public view returns (uint256) {\n        require(index < balanceOf(owner), \"ERC721Enumerable: owner index out of bounds\");\n        return _ownedTokens[owner][index];\n    }\n\n    /**\n     * @dev Gets the total amount of tokens stored by the contract.\n     * @return uint256 representing the total amount of tokens\n     */\n    function totalSupply() public view returns (uint256) {\n        return _allTokens.length;\n    }\n\n    /**\n     * @dev Gets the token ID at a given index of all the tokens in this contract\n     * Reverts if the index is greater or equal to the total number of tokens.\n     * @param index uint256 representing the index to be accessed of the tokens list\n     * @return uint256 token ID at the given index of the tokens list\n     */\n    function tokenByIndex(uint256 index) public view returns (uint256) {\n        require(index < totalSupply(), \"ERC721Enumerable: global index out of bounds\");\n        return _allTokens[index];\n    }\n\n    /**\n     * @dev Internal function to transfer ownership of a given token ID to another address.\n     * As opposed to transferFrom, this imposes no restrictions on msg.sender.\n     * @param from current owner of the token\n     * @param to address to receive the ownership of the given token ID\n     * @param tokenId uint256 ID of the token to be transferred\n     */\n    function _transferFrom(address from, address to, uint256 tokenId) internal {\n        super._transferFrom(from, to, tokenId);\n\n        _removeTokenFromOwnerEnumeration(from, tokenId);\n\n        _addTokenToOwnerEnumeration(to, tokenId);\n    }\n\n    /**\n     * @dev Internal function to mint a new token.\n     * Reverts if the given token ID already exists.\n     * @param to address the beneficiary that will own the minted token\n     * @param tokenId uint256 ID of the token to be minted\n     */\n    function _mint(address to, uint256 tokenId) internal {\n        super._mint(to, tokenId);\n\n        _addTokenToOwnerEnumeration(to, tokenId);\n\n        _addTokenToAllTokensEnumeration(tokenId);\n    }\n\n    /**\n     * @dev Internal function to burn a specific token.\n     * Reverts if the token does not exist.\n     * Deprecated, use _burn(uint256) instead.\n     * @param owner owner of the token to burn\n     * @param tokenId uint256 ID of the token being burned\n     */\n    function _burn(address owner, uint256 tokenId) internal {\n        super._burn(owner, tokenId);\n\n        _removeTokenFromOwnerEnumeration(owner, tokenId);\n        // Since tokenId will be deleted, we can clear its slot in _ownedTokensIndex to trigger a gas refund\n        _ownedTokensIndex[tokenId] = 0;\n\n        _removeTokenFromAllTokensEnumeration(tokenId);\n    }\n\n    /**\n     * @dev Gets the list of token IDs of the requested owner.\n     * @param owner address owning the tokens\n     * @return uint256[] List of token IDs owned by the requested address\n     */\n    function _tokensOfOwner(address owner) internal view returns (uint256[] storage) {\n        return _ownedTokens[owner];\n    }\n\n    /**\n     * @dev Private function to add a token to this extension's ownership-tracking data structures.\n     * @param to address representing the new owner of the given token ID\n     * @param tokenId uint256 ID of the token to be added to the tokens list of the given address\n     */\n    function _addTokenToOwnerEnumeration(address to, uint256 tokenId) private {\n        _ownedTokensIndex[tokenId] = _ownedTokens[to].length;\n        _ownedTokens[to].push(tokenId);\n    }\n\n    /**\n     * @dev Private function to add a token to this extension's token tracking data structures.\n     * @param tokenId uint256 ID of the token to be added to the tokens list\n     */\n    function _addTokenToAllTokensEnumeration(uint256 tokenId) private {\n        _allTokensIndex[tokenId] = _allTokens.length;\n        _allTokens.push(tokenId);\n    }\n\n    /**\n     * @dev Private function to remove a token from this extension's ownership-tracking data structures. Note that\n     * while the token is not assigned a new owner, the _ownedTokensIndex mapping is _not_ updated: this allows for\n     * gas optimizations e.g. when performing a transfer operation (avoiding double writes).\n     * This has O(1) time complexity, but alters the order of the _ownedTokens array.\n     * @param from address representing the previous owner of the given token ID\n     * @param tokenId uint256 ID of the token to be removed from the tokens list of the given address\n     */\n    function _removeTokenFromOwnerEnumeration(address from, uint256 tokenId) private {\n        // To prevent a gap in from's tokens array, we store the last token in the index of the token to delete, and\n        // then delete the last slot (swap and pop).\n\n        uint256 lastTokenIndex = _ownedTokens[from].length.sub(1);\n        uint256 tokenIndex = _ownedTokensIndex[tokenId];\n\n        // When the token to delete is the last token, the swap operation is unnecessary\n        if (tokenIndex != lastTokenIndex) {\n            uint256 lastTokenId = _ownedTokens[from][lastTokenIndex];\n\n            _ownedTokens[from][tokenIndex] = lastTokenId; // Move the last token to the slot of the to-delete token\n            _ownedTokensIndex[lastTokenId] = tokenIndex; // Update the moved token's index\n        }\n\n        // This also deletes the contents at the last position of the array\n        _ownedTokens[from].length--;\n\n        // Note that _ownedTokensIndex[tokenId] hasn't been cleared: it still points to the old slot (now occupied by\n        // lastTokenId, or just over the end of the array if the token was the last one).\n    }\n\n    /**\n     * @dev Private function to remove a token from this extension's token tracking data structures.\n     * This has O(1) time complexity, but alters the order of the _allTokens array.\n     * @param tokenId uint256 ID of the token to be removed from the tokens list\n     */\n    function _removeTokenFromAllTokensEnumeration(uint256 tokenId) private {\n        // To prevent a gap in the tokens array, we store the last token in the index of the token to delete, and\n        // then delete the last slot (swap and pop).\n\n        uint256 lastTokenIndex = _allTokens.length.sub(1);\n        uint256 tokenIndex = _allTokensIndex[tokenId];\n\n        // When the token to delete is the last token, the swap operation is unnecessary. However, since this occurs so\n        // rarely (when the last minted token is burnt) that we still do the swap here to avoid the gas cost of adding\n        // an 'if' statement (like in _removeTokenFromOwnerEnumeration)\n        uint256 lastTokenId = _allTokens[lastTokenIndex];\n\n        _allTokens[tokenIndex] = lastTokenId; // Move the last token to the slot of the to-delete token\n        _allTokensIndex[lastTokenId] = tokenIndex; // Update the moved token's index\n\n        // This also deletes the contents at the last position of the array\n        _allTokens.length--;\n        _allTokensIndex[tokenId] = 0;\n    }\n}\n\n// File: @openzeppelin/contracts/token/ERC721/IERC721Metadata.sol\n\npragma solidity ^0.5.0;\n\n\n/**\n * @title ERC-721 Non-Fungible Token Standard, optional metadata extension\n * @dev See https://eips.ethereum.org/EIPS/eip-721\n */\ncontract IERC721Metadata is IERC721 {\n    function name() external view returns (string memory);\n    function symbol() external view returns (string memory);\n    function tokenURI(uint256 tokenId) external view returns (string memory);\n}\n\n// File: @openzeppelin/contracts/token/ERC721/ERC721Metadata.sol\n\npragma solidity ^0.5.0;\n\n\n\n\ncontract ERC721Metadata is ERC165, ERC721, IERC721Metadata {\n    // Token name\n    string private _name;\n\n    // Token symbol\n    string private _symbol;\n\n    // Optional mapping for token URIs\n    mapping(uint256 => string) private _tokenURIs;\n\n    /*\n     *     bytes4(keccak256('name()')) == 0x06fdde03\n     *     bytes4(keccak256('symbol()')) == 0x95d89b41\n     *     bytes4(keccak256('tokenURI(uint256)')) == 0xc87b56dd\n     *\n     *     => 0x06fdde03 ^ 0x95d89b41 ^ 0xc87b56dd == 0x5b5e139f\n     */\n    bytes4 private constant _INTERFACE_ID_ERC721_METADATA = 0x5b5e139f;\n\n    /**\n     * @dev Constructor function\n     */\n    constructor (string memory name, string memory symbol) public {\n        _name = name;\n        _symbol = symbol;\n\n        // register the supported interfaces to conform to ERC721 via ERC165\n        _registerInterface(_INTERFACE_ID_ERC721_METADATA);\n    }\n\n    /**\n     * @dev Gets the token name.\n     * @return string representing the token name\n     */\n    function name() external view returns (string memory) {\n        return _name;\n    }\n\n    /**\n     * @dev Gets the token symbol.\n     * @return string representing the token symbol\n     */\n    function symbol() external view returns (string memory) {\n        return _symbol;\n    }\n\n    /**\n     * @dev Returns an URI for a given token ID.\n     * Throws if the token ID does not exist. May return an empty string.\n     * @param tokenId uint256 ID of the token to query\n     */\n    function tokenURI(uint256 tokenId) external view returns (string memory) {\n        require(_exists(tokenId), \"ERC721Metadata: URI query for nonexistent token\");\n        return _tokenURIs[tokenId];\n    }\n\n    /**\n     * @dev Internal function to set the token URI for a given token.\n     * Reverts if the token ID does not exist.\n     * @param tokenId uint256 ID of the token to set its URI\n     * @param uri string URI to assign\n     */\n    function _setTokenURI(uint256 tokenId, string memory uri) internal {\n        require(_exists(tokenId), \"ERC721Metadata: URI set of nonexistent token\");\n        _tokenURIs[tokenId] = uri;\n    }\n\n    /**\n     * @dev Internal function to burn a specific token.\n     * Reverts if the token does not exist.\n     * Deprecated, use _burn(uint256) instead.\n     * @param owner owner of the token to burn\n     * @param tokenId uint256 ID of the token being burned by the msg.sender\n     */\n    function _burn(address owner, uint256 tokenId) internal {\n        super._burn(owner, tokenId);\n\n        // Clear metadata (if any)\n        if (bytes(_tokenURIs[tokenId]).length != 0) {\n            delete _tokenURIs[tokenId];\n        }\n    }\n}\n\n// File: @openzeppelin/contracts/token/ERC721/ERC721Full.sol\n\npragma solidity ^0.5.0;\n\n\n\n\n/**\n * @title Full ERC721 Token\n * This implementation includes all the required and some optional functionality of the ERC721 standard\n * Moreover, it includes approve all functionality using operator terminology\n * @dev see https://eips.ethereum.org/EIPS/eip-721\n */\ncontract ERC721Full is ERC721, ERC721Enumerable, ERC721Metadata {\n    constructor (string memory name, string memory symbol) public ERC721Metadata(name, symbol) {\n        // solhint-disable-previous-line no-empty-blocks\n    }\n}\n",
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+                          "typeString": "address"
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+                              "typeString": "uint256"
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+                          "src": "17616:18:1",
+                          "typeDescriptions": {
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+                        "referencedDeclaration": 596,
+                        "src": "17734:4:1",
+                        "typeDescriptions": {
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+                          "typeString": "address"
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+                          "typeString": "address"
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+                          "typeString": "address"
+                        },
+                        {
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+                          "typeString": "uint256"
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+                      "name": "_transferFrom",
+                      "nodeType": "Identifier",
+                      "overloadedDeclarations": [],
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+                      "src": "17720:13:1",
+                      "typeDescriptions": {
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+                      "typeString": "address"
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+                  "storageLocation": "default",
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+                    "name": "address",
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+                    "stateMutability": "nonpayable",
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+                      "typeString": "address"
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+                  "visibility": "internal"
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+                        "name": "from",
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+                        "src": "18501:2:1",
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+                        "src": "18505:7:1",
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+                          "typeString": "address"
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+                          "typeString": "address"
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+                          "typeString": "uint256"
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+                              "src": "23994:15:1",
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+                              "lValueRequested": false,
+                              "nodeType": "ElementaryTypeNameExpression",
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+                                "typeIdentifier": "t_type$_t_address_$",
+                                "typeString": "type(address)"
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+                              "typeName": "address"
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+                            "isPure": true,
+                            "kind": "typeConversion",
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+                            "names": [],
+                            "nodeType": "FunctionCall",
+                            "src": "24021:10:1",
+                            "typeDescriptions": {
+                              "typeIdentifier": "t_address_payable",
+                              "typeString": "address payable"
+                            }
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+                          "src": "23994:37:1",
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+                            "typeIdentifier": "t_address",
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+                          "typeString": "uint256"
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+                        "src": "27885:2:1",
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+                          "typeString": "address"
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+                        "name": "tokenId",
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+                          "typeString": "address"
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+          },
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+                        "src": "28236:2:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        }
+                      },
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+                        "id": 1096,
+                        "name": "tokenId",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 1089,
+                        "src": "28240:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      }
+                    ],
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+                      "argumentTypes": [
+                        {
+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        },
+                        {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      ],
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+                        "id": 1092,
+                        "name": "super",
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+                        "src": "28224:5:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_super$_ERC721Enumerable_$1302",
+                          "typeString": "contract super ERC721Enumerable"
+                        }
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+                      "src": "28224:11:1",
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+                        "typeString": "function (address,uint256)"
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+                    "isPure": false,
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+                    "src": "28224:24:1",
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+                        "name": "to",
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+                        "referencedDeclaration": 1087,
+                        "src": "28287:2:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        }
+                      },
+                      {
+                        "argumentTypes": null,
+                        "id": 1101,
+                        "name": "tokenId",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 1089,
+                        "src": "28291:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      }
+                    ],
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+                      "argumentTypes": [
+                        {
+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        },
+                        {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      ],
+                      "id": 1099,
+                      "name": "_addTokenToOwnerEnumeration",
+                      "nodeType": "Identifier",
+                      "overloadedDeclarations": [],
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+                      "src": "28259:27:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_function_internal_nonpayable$_t_address_$_t_uint256_$returns$__$",
+                        "typeString": "function (address,uint256)"
+                      }
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+                    "isConstant": false,
+                    "isLValue": false,
+                    "isPure": false,
+                    "kind": "functionCall",
+                    "lValueRequested": false,
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+                    "nodeType": "FunctionCall",
+                    "src": "28259:40:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_tuple$__$",
+                      "typeString": "tuple()"
+                    }
+                  },
+                  "id": 1103,
+                  "nodeType": "ExpressionStatement",
+                  "src": "28259:40:1"
+                },
+                {
+                  "expression": {
+                    "argumentTypes": null,
+                    "arguments": [
+                      {
+                        "argumentTypes": null,
+                        "id": 1105,
+                        "name": "tokenId",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 1089,
+                        "src": "28342:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      }
+                    ],
+                    "expression": {
+                      "argumentTypes": [
+                        {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      ],
+                      "id": 1104,
+                      "name": "_addTokenToAllTokensEnumeration",
+                      "nodeType": "Identifier",
+                      "overloadedDeclarations": [],
+                      "referencedDeclaration": 1195,
+                      "src": "28310:31:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_function_internal_nonpayable$_t_uint256_$returns$__$",
+                        "typeString": "function (uint256)"
+                      }
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+                    "isLValue": false,
+                    "isPure": false,
+                    "kind": "functionCall",
+                    "lValueRequested": false,
+                    "names": [],
+                    "nodeType": "FunctionCall",
+                    "src": "28310:40:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_tuple$__$",
+                      "typeString": "tuple()"
+                    }
+                  },
+                  "id": 1107,
+                  "nodeType": "ExpressionStatement",
+                  "src": "28310:40:1"
+                }
+              ]
+            },
+            "documentation": "@dev Internal function to mint a new token.\nReverts if the given token ID already exists.\n@param to address the beneficiary that will own the minted token\n@param tokenId uint256 ID of the token to be minted",
+            "id": 1109,
+            "implemented": true,
+            "kind": "function",
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+            "name": "_mint",
+            "nodeType": "FunctionDefinition",
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+              "nodeType": "ParameterList",
+              "parameters": [
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+                  "id": 1087,
+                  "name": "to",
+                  "nodeType": "VariableDeclaration",
+                  "scope": 1109,
+                  "src": "28176:10:1",
+                  "stateVariable": false,
+                  "storageLocation": "default",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_address",
+                    "typeString": "address"
+                  },
+                  "typeName": {
+                    "id": 1086,
+                    "name": "address",
+                    "nodeType": "ElementaryTypeName",
+                    "src": "28176:7:1",
+                    "stateMutability": "nonpayable",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_address",
+                      "typeString": "address"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                },
+                {
+                  "constant": false,
+                  "id": 1089,
+                  "name": "tokenId",
+                  "nodeType": "VariableDeclaration",
+                  "scope": 1109,
+                  "src": "28188:15:1",
+                  "stateVariable": false,
+                  "storageLocation": "default",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_uint256",
+                    "typeString": "uint256"
+                  },
+                  "typeName": {
+                    "id": 1088,
+                    "name": "uint256",
+                    "nodeType": "ElementaryTypeName",
+                    "src": "28188:7:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_uint256",
+                      "typeString": "uint256"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                }
+              ],
+              "src": "28175:29:1"
+            },
+            "returnParameters": {
+              "id": 1091,
+              "nodeType": "ParameterList",
+              "parameters": [],
+              "src": "28214:0:1"
+            },
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+            "src": "28161:196:1",
+            "stateMutability": "nonpayable",
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+            "visibility": "internal"
+          },
+          {
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+              "id": 1138,
+              "nodeType": "Block",
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+                    "arguments": [
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+                        "argumentTypes": null,
+                        "id": 1119,
+                        "name": "owner",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 1111,
+                        "src": "28710:5:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        }
+                      },
+                      {
+                        "argumentTypes": null,
+                        "id": 1120,
+                        "name": "tokenId",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 1113,
+                        "src": "28717:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      }
+                    ],
+                    "expression": {
+                      "argumentTypes": [
+                        {
+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        },
+                        {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      ],
+                      "expression": {
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+                        "id": 1116,
+                        "name": "super",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 1572,
+                        "src": "28698:5:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_super$_ERC721Enumerable_$1302",
+                          "typeString": "contract super ERC721Enumerable"
+                        }
+                      },
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+                      "isConstant": false,
+                      "isLValue": false,
+                      "isPure": false,
+                      "lValueRequested": false,
+                      "memberName": "_burn",
+                      "nodeType": "MemberAccess",
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+                      "src": "28698:11:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_function_internal_nonpayable$_t_address_$_t_uint256_$returns$__$",
+                        "typeString": "function (address,uint256)"
+                      }
+                    },
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+                    "isLValue": false,
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+                    "kind": "functionCall",
+                    "lValueRequested": false,
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+                    "src": "28698:27:1",
+                    "typeDescriptions": {
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+                      "typeString": "tuple()"
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+                  "src": "28698:27:1"
+                },
+                {
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+                    "arguments": [
+                      {
+                        "argumentTypes": null,
+                        "id": 1124,
+                        "name": "owner",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 1111,
+                        "src": "28769:5:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        }
+                      },
+                      {
+                        "argumentTypes": null,
+                        "id": 1125,
+                        "name": "tokenId",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 1113,
+                        "src": "28776:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      }
+                    ],
+                    "expression": {
+                      "argumentTypes": [
+                        {
+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        },
+                        {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      ],
+                      "id": 1123,
+                      "name": "_removeTokenFromOwnerEnumeration",
+                      "nodeType": "Identifier",
+                      "overloadedDeclarations": [],
+                      "referencedDeclaration": 1252,
+                      "src": "28736:32:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_function_internal_nonpayable$_t_address_$_t_uint256_$returns$__$",
+                        "typeString": "function (address,uint256)"
+                      }
+                    },
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+                    "isConstant": false,
+                    "isLValue": false,
+                    "isPure": false,
+                    "kind": "functionCall",
+                    "lValueRequested": false,
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+                    "nodeType": "FunctionCall",
+                    "src": "28736:48:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_tuple$__$",
+                      "typeString": "tuple()"
+                    }
+                  },
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+                  "nodeType": "ExpressionStatement",
+                  "src": "28736:48:1"
+                },
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+                    "isLValue": false,
+                    "isPure": false,
+                    "lValueRequested": false,
+                    "leftHandSide": {
+                      "argumentTypes": null,
+                      "baseExpression": {
+                        "argumentTypes": null,
+                        "id": 1128,
+                        "name": "_ownedTokensIndex",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 985,
+                        "src": "28903:17:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_mapping$_t_uint256_$_t_uint256_$",
+                          "typeString": "mapping(uint256 => uint256)"
+                        }
+                      },
+                      "id": 1130,
+                      "indexExpression": {
+                        "argumentTypes": null,
+                        "id": 1129,
+                        "name": "tokenId",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 1113,
+                        "src": "28921:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      },
+                      "isConstant": false,
+                      "isLValue": true,
+                      "isPure": false,
+                      "lValueRequested": true,
+                      "nodeType": "IndexAccess",
+                      "src": "28903:26:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_uint256",
+                        "typeString": "uint256"
+                      }
+                    },
+                    "nodeType": "Assignment",
+                    "operator": "=",
+                    "rightHandSide": {
+                      "argumentTypes": null,
+                      "hexValue": "30",
+                      "id": 1131,
+                      "isConstant": false,
+                      "isLValue": false,
+                      "isPure": true,
+                      "kind": "number",
+                      "lValueRequested": false,
+                      "nodeType": "Literal",
+                      "src": "28932:1:1",
+                      "subdenomination": null,
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_rational_0_by_1",
+                        "typeString": "int_const 0"
+                      },
+                      "value": "0"
+                    },
+                    "src": "28903:30:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_uint256",
+                      "typeString": "uint256"
+                    }
+                  },
+                  "id": 1133,
+                  "nodeType": "ExpressionStatement",
+                  "src": "28903:30:1"
+                },
+                {
+                  "expression": {
+                    "argumentTypes": null,
+                    "arguments": [
+                      {
+                        "argumentTypes": null,
+                        "id": 1135,
+                        "name": "tokenId",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 1113,
+                        "src": "28981:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      }
+                    ],
+                    "expression": {
+                      "argumentTypes": [
+                        {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      ],
+                      "id": 1134,
+                      "name": "_removeTokenFromAllTokensEnumeration",
+                      "nodeType": "Identifier",
+                      "overloadedDeclarations": [],
+                      "referencedDeclaration": 1301,
+                      "src": "28944:36:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_function_internal_nonpayable$_t_uint256_$returns$__$",
+                        "typeString": "function (uint256)"
+                      }
+                    },
+                    "id": 1136,
+                    "isConstant": false,
+                    "isLValue": false,
+                    "isPure": false,
+                    "kind": "functionCall",
+                    "lValueRequested": false,
+                    "names": [],
+                    "nodeType": "FunctionCall",
+                    "src": "28944:45:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_tuple$__$",
+                      "typeString": "tuple()"
+                    }
+                  },
+                  "id": 1137,
+                  "nodeType": "ExpressionStatement",
+                  "src": "28944:45:1"
+                }
+              ]
+            },
+            "documentation": "@dev Internal function to burn a specific token.\nReverts if the token does not exist.\nDeprecated, use _burn(uint256) instead.\n@param owner owner of the token to burn\n@param tokenId uint256 ID of the token being burned",
+            "id": 1139,
+            "implemented": true,
+            "kind": "function",
+            "modifiers": [],
+            "name": "_burn",
+            "nodeType": "FunctionDefinition",
+            "parameters": {
+              "id": 1114,
+              "nodeType": "ParameterList",
+              "parameters": [
+                {
+                  "constant": false,
+                  "id": 1111,
+                  "name": "owner",
+                  "nodeType": "VariableDeclaration",
+                  "scope": 1139,
+                  "src": "28647:13:1",
+                  "stateVariable": false,
+                  "storageLocation": "default",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_address",
+                    "typeString": "address"
+                  },
+                  "typeName": {
+                    "id": 1110,
+                    "name": "address",
+                    "nodeType": "ElementaryTypeName",
+                    "src": "28647:7:1",
+                    "stateMutability": "nonpayable",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_address",
+                      "typeString": "address"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                },
+                {
+                  "constant": false,
+                  "id": 1113,
+                  "name": "tokenId",
+                  "nodeType": "VariableDeclaration",
+                  "scope": 1139,
+                  "src": "28662:15:1",
+                  "stateVariable": false,
+                  "storageLocation": "default",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_uint256",
+                    "typeString": "uint256"
+                  },
+                  "typeName": {
+                    "id": 1112,
+                    "name": "uint256",
+                    "nodeType": "ElementaryTypeName",
+                    "src": "28662:7:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_uint256",
+                      "typeString": "uint256"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                }
+              ],
+              "src": "28646:32:1"
+            },
+            "returnParameters": {
+              "id": 1115,
+              "nodeType": "ParameterList",
+              "parameters": [],
+              "src": "28688:0:1"
+            },
+            "scope": 1302,
+            "src": "28632:364:1",
+            "stateMutability": "nonpayable",
+            "superFunction": 811,
+            "visibility": "internal"
+          },
+          {
+            "body": {
+              "id": 1151,
+              "nodeType": "Block",
+              "src": "29282:43:1",
+              "statements": [
+                {
+                  "expression": {
+                    "argumentTypes": null,
+                    "baseExpression": {
+                      "argumentTypes": null,
+                      "id": 1147,
+                      "name": "_ownedTokens",
+                      "nodeType": "Identifier",
+                      "overloadedDeclarations": [],
+                      "referencedDeclaration": 981,
+                      "src": "29299:12:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_mapping$_t_address_$_t_array$_t_uint256_$dyn_storage_$",
+                        "typeString": "mapping(address => uint256[] storage ref)"
+                      }
+                    },
+                    "id": 1149,
+                    "indexExpression": {
+                      "argumentTypes": null,
+                      "id": 1148,
+                      "name": "owner",
+                      "nodeType": "Identifier",
+                      "overloadedDeclarations": [],
+                      "referencedDeclaration": 1141,
+                      "src": "29312:5:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_address",
+                        "typeString": "address"
+                      }
+                    },
+                    "isConstant": false,
+                    "isLValue": true,
+                    "isPure": false,
+                    "lValueRequested": false,
+                    "nodeType": "IndexAccess",
+                    "src": "29299:19:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_array$_t_uint256_$dyn_storage",
+                      "typeString": "uint256[] storage ref"
+                    }
+                  },
+                  "functionReturnParameters": 1146,
+                  "id": 1150,
+                  "nodeType": "Return",
+                  "src": "29292:26:1"
+                }
+              ]
+            },
+            "documentation": "@dev Gets the list of token IDs of the requested owner.\n@param owner address owning the tokens\n@return uint256[] List of token IDs owned by the requested address",
+            "id": 1152,
+            "implemented": true,
+            "kind": "function",
+            "modifiers": [],
+            "name": "_tokensOfOwner",
+            "nodeType": "FunctionDefinition",
+            "parameters": {
+              "id": 1142,
+              "nodeType": "ParameterList",
+              "parameters": [
+                {
+                  "constant": false,
+                  "id": 1141,
+                  "name": "owner",
+                  "nodeType": "VariableDeclaration",
+                  "scope": 1152,
+                  "src": "29225:13:1",
+                  "stateVariable": false,
+                  "storageLocation": "default",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_address",
+                    "typeString": "address"
+                  },
+                  "typeName": {
+                    "id": 1140,
+                    "name": "address",
+                    "nodeType": "ElementaryTypeName",
+                    "src": "29225:7:1",
+                    "stateMutability": "nonpayable",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_address",
+                      "typeString": "address"
+                    }
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+                        "typeIdentifier": "t_mapping$_t_uint256_$_t_uint256_$",
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+                    }
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+                  "src": "31102:47:1"
+                },
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+                      "src": "31253:10:1",
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+                        "typeIdentifier": "t_uint256",
+                        "typeString": "uint256"
+                      }
+                    },
+                    "nodeType": "BinaryOperation",
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+                      "name": "lastTokenIndex",
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+                      "src": "31267:14:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_uint256",
+                        "typeString": "uint256"
+                      }
+                    },
+                    "src": "31253:28:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_bool",
+                      "typeString": "bool"
+                    }
+                  },
+                  "falseBody": null,
+                  "id": 1244,
+                  "nodeType": "IfStatement",
+                  "src": "31249:323:1",
+                  "trueBody": {
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+                    "nodeType": "Block",
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+                    "statements": [
+                      {
+                        "assignments": [
+                          1222
+                        ],
+                        "declarations": [
+                          {
+                            "constant": false,
+                            "id": 1222,
+                            "name": "lastTokenId",
+                            "nodeType": "VariableDeclaration",
+                            "scope": 1243,
+                            "src": "31297:19:1",
+                            "stateVariable": false,
+                            "storageLocation": "default",
+                            "typeDescriptions": {
+                              "typeIdentifier": "t_uint256",
+                              "typeString": "uint256"
+                            },
+                            "typeName": {
+                              "id": 1221,
+                              "name": "uint256",
+                              "nodeType": "ElementaryTypeName",
+                              "src": "31297:7:1",
+                              "typeDescriptions": {
+                                "typeIdentifier": "t_uint256",
+                                "typeString": "uint256"
+                              }
+                            },
+                            "value": null,
+                            "visibility": "internal"
+                          }
+                        ],
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+                        "initialValue": {
+                          "argumentTypes": null,
+                          "baseExpression": {
+                            "argumentTypes": null,
+                            "baseExpression": {
+                              "argumentTypes": null,
+                              "id": 1223,
+                              "name": "_ownedTokens",
+                              "nodeType": "Identifier",
+                              "overloadedDeclarations": [],
+                              "referencedDeclaration": 981,
+                              "src": "31319:12:1",
+                              "typeDescriptions": {
+                                "typeIdentifier": "t_mapping$_t_address_$_t_array$_t_uint256_$dyn_storage_$",
+                                "typeString": "mapping(address => uint256[] storage ref)"
+                              }
+                            },
+                            "id": 1225,
+                            "indexExpression": {
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+                              "id": 1224,
+                              "name": "from",
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+                              "overloadedDeclarations": [],
+                              "referencedDeclaration": 1197,
+                              "src": "31332:4:1",
+                              "typeDescriptions": {
+                                "typeIdentifier": "t_address",
+                                "typeString": "address"
+                              }
+                            },
+                            "isConstant": false,
+                            "isLValue": true,
+                            "isPure": false,
+                            "lValueRequested": false,
+                            "nodeType": "IndexAccess",
+                            "src": "31319:18:1",
+                            "typeDescriptions": {
+                              "typeIdentifier": "t_array$_t_uint256_$dyn_storage",
+                              "typeString": "uint256[] storage ref"
+                            }
+                          },
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+                            "argumentTypes": null,
+                            "id": 1226,
+                            "name": "lastTokenIndex",
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+                            "src": "31338:14:1",
+                            "typeDescriptions": {
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+                              "typeString": "uint256"
+                            }
+                          },
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+                          "isPure": false,
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+                          "nodeType": "IndexAccess",
+                          "src": "31319:34:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_uint256",
+                            "typeString": "uint256"
+                          }
+                        },
+                        "nodeType": "VariableDeclarationStatement",
+                        "src": "31297:56:1"
+                      },
+                      {
+                        "expression": {
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+                          "isLValue": false,
+                          "isPure": false,
+                          "lValueRequested": false,
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+                              "argumentTypes": null,
+                              "baseExpression": {
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+                                "id": 1229,
+                                "name": "_ownedTokens",
+                                "nodeType": "Identifier",
+                                "overloadedDeclarations": [],
+                                "referencedDeclaration": 981,
+                                "src": "31368:12:1",
+                                "typeDescriptions": {
+                                  "typeIdentifier": "t_mapping$_t_address_$_t_array$_t_uint256_$dyn_storage_$",
+                                  "typeString": "mapping(address => uint256[] storage ref)"
+                                }
+                              },
+                              "id": 1232,
+                              "indexExpression": {
+                                "argumentTypes": null,
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+                                "name": "from",
+                                "nodeType": "Identifier",
+                                "overloadedDeclarations": [],
+                                "referencedDeclaration": 1197,
+                                "src": "31381:4:1",
+                                "typeDescriptions": {
+                                  "typeIdentifier": "t_address",
+                                  "typeString": "address"
+                                }
+                              },
+                              "isConstant": false,
+                              "isLValue": true,
+                              "isPure": false,
+                              "lValueRequested": false,
+                              "nodeType": "IndexAccess",
+                              "src": "31368:18:1",
+                              "typeDescriptions": {
+                                "typeIdentifier": "t_array$_t_uint256_$dyn_storage",
+                                "typeString": "uint256[] storage ref"
+                              }
+                            },
+                            "id": 1233,
+                            "indexExpression": {
+                              "argumentTypes": null,
+                              "id": 1231,
+                              "name": "tokenIndex",
+                              "nodeType": "Identifier",
+                              "overloadedDeclarations": [],
+                              "referencedDeclaration": 1213,
+                              "src": "31387:10:1",
+                              "typeDescriptions": {
+                                "typeIdentifier": "t_uint256",
+                                "typeString": "uint256"
+                              }
+                            },
+                            "isConstant": false,
+                            "isLValue": true,
+                            "isPure": false,
+                            "lValueRequested": true,
+                            "nodeType": "IndexAccess",
+                            "src": "31368:30:1",
+                            "typeDescriptions": {
+                              "typeIdentifier": "t_uint256",
+                              "typeString": "uint256"
+                            }
+                          },
+                          "nodeType": "Assignment",
+                          "operator": "=",
+                          "rightHandSide": {
+                            "argumentTypes": null,
+                            "id": 1234,
+                            "name": "lastTokenId",
+                            "nodeType": "Identifier",
+                            "overloadedDeclarations": [],
+                            "referencedDeclaration": 1222,
+                            "src": "31401:11:1",
+                            "typeDescriptions": {
+                              "typeIdentifier": "t_uint256",
+                              "typeString": "uint256"
+                            }
+                          },
+                          "src": "31368:44:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_uint256",
+                            "typeString": "uint256"
+                          }
+                        },
+                        "id": 1236,
+                        "nodeType": "ExpressionStatement",
+                        "src": "31368:44:1"
+                      },
+                      {
+                        "expression": {
+                          "argumentTypes": null,
+                          "id": 1241,
+                          "isConstant": false,
+                          "isLValue": false,
+                          "isPure": false,
+                          "lValueRequested": false,
+                          "leftHandSide": {
+                            "argumentTypes": null,
+                            "baseExpression": {
+                              "argumentTypes": null,
+                              "id": 1237,
+                              "name": "_ownedTokensIndex",
+                              "nodeType": "Identifier",
+                              "overloadedDeclarations": [],
+                              "referencedDeclaration": 985,
+                              "src": "31484:17:1",
+                              "typeDescriptions": {
+                                "typeIdentifier": "t_mapping$_t_uint256_$_t_uint256_$",
+                                "typeString": "mapping(uint256 => uint256)"
+                              }
+                            },
+                            "id": 1239,
+                            "indexExpression": {
+                              "argumentTypes": null,
+                              "id": 1238,
+                              "name": "lastTokenId",
+                              "nodeType": "Identifier",
+                              "overloadedDeclarations": [],
+                              "referencedDeclaration": 1222,
+                              "src": "31502:11:1",
+                              "typeDescriptions": {
+                                "typeIdentifier": "t_uint256",
+                                "typeString": "uint256"
+                              }
+                            },
+                            "isConstant": false,
+                            "isLValue": true,
+                            "isPure": false,
+                            "lValueRequested": true,
+                            "nodeType": "IndexAccess",
+                            "src": "31484:30:1",
+                            "typeDescriptions": {
+                              "typeIdentifier": "t_uint256",
+                              "typeString": "uint256"
+                            }
+                          },
+                          "nodeType": "Assignment",
+                          "operator": "=",
+                          "rightHandSide": {
+                            "argumentTypes": null,
+                            "id": 1240,
+                            "name": "tokenIndex",
+                            "nodeType": "Identifier",
+                            "overloadedDeclarations": [],
+                            "referencedDeclaration": 1213,
+                            "src": "31517:10:1",
+                            "typeDescriptions": {
+                              "typeIdentifier": "t_uint256",
+                              "typeString": "uint256"
+                            }
+                          },
+                          "src": "31484:43:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_uint256",
+                            "typeString": "uint256"
+                          }
+                        },
+                        "id": 1242,
+                        "nodeType": "ExpressionStatement",
+                        "src": "31484:43:1"
+                      }
+                    ]
+                  }
+                },
+                {
+                  "expression": {
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+                    "id": 1249,
+                    "isConstant": false,
+                    "isLValue": false,
+                    "isPure": false,
+                    "lValueRequested": false,
+                    "nodeType": "UnaryOperation",
+                    "operator": "--",
+                    "prefix": false,
+                    "src": "31658:27:1",
+                    "subExpression": {
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+                      "expression": {
+                        "argumentTypes": null,
+                        "baseExpression": {
+                          "argumentTypes": null,
+                          "id": 1245,
+                          "name": "_ownedTokens",
+                          "nodeType": "Identifier",
+                          "overloadedDeclarations": [],
+                          "referencedDeclaration": 981,
+                          "src": "31658:12:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_mapping$_t_address_$_t_array$_t_uint256_$dyn_storage_$",
+                            "typeString": "mapping(address => uint256[] storage ref)"
+                          }
+                        },
+                        "id": 1247,
+                        "indexExpression": {
+                          "argumentTypes": null,
+                          "id": 1246,
+                          "name": "from",
+                          "nodeType": "Identifier",
+                          "overloadedDeclarations": [],
+                          "referencedDeclaration": 1197,
+                          "src": "31671:4:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_address",
+                            "typeString": "address"
+                          }
+                        },
+                        "isConstant": false,
+                        "isLValue": true,
+                        "isPure": false,
+                        "lValueRequested": false,
+                        "nodeType": "IndexAccess",
+                        "src": "31658:18:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_array$_t_uint256_$dyn_storage",
+                          "typeString": "uint256[] storage ref"
+                        }
+                      },
+                      "id": 1248,
+                      "isConstant": false,
+                      "isLValue": true,
+                      "isPure": false,
+                      "lValueRequested": true,
+                      "memberName": "length",
+                      "nodeType": "MemberAccess",
+                      "referencedDeclaration": null,
+                      "src": "31658:25:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_uint256",
+                        "typeString": "uint256"
+                      }
+                    },
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+                      "typeIdentifier": "t_uint256",
+                      "typeString": "uint256"
+                    }
+                  },
+                  "id": 1250,
+                  "nodeType": "ExpressionStatement",
+                  "src": "31658:27:1"
+                }
+              ]
+            },
+            "documentation": "@dev Private function to remove a token from this extension's ownership-tracking data structures. Note that\nwhile the token is not assigned a new owner, the _ownedTokensIndex mapping is _not_ updated: this allows for\ngas optimizations e.g. when performing a transfer operation (avoiding double writes).\nThis has O(1) time complexity, but alters the order of the _ownedTokens array.\n@param from address representing the previous owner of the given token ID\n@param tokenId uint256 ID of the token to be removed from the tokens list of the given address",
+            "id": 1252,
+            "implemented": true,
+            "kind": "function",
+            "modifiers": [],
+            "name": "_removeTokenFromOwnerEnumeration",
+            "nodeType": "FunctionDefinition",
+            "parameters": {
+              "id": 1200,
+              "nodeType": "ParameterList",
+              "parameters": [
+                {
+                  "constant": false,
+                  "id": 1197,
+                  "name": "from",
+                  "nodeType": "VariableDeclaration",
+                  "scope": 1252,
+                  "src": "30815:12:1",
+                  "stateVariable": false,
+                  "storageLocation": "default",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_address",
+                    "typeString": "address"
+                  },
+                  "typeName": {
+                    "id": 1196,
+                    "name": "address",
+                    "nodeType": "ElementaryTypeName",
+                    "src": "30815:7:1",
+                    "stateMutability": "nonpayable",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_address",
+                      "typeString": "address"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                },
+                {
+                  "constant": false,
+                  "id": 1199,
+                  "name": "tokenId",
+                  "nodeType": "VariableDeclaration",
+                  "scope": 1252,
+                  "src": "30829:15:1",
+                  "stateVariable": false,
+                  "storageLocation": "default",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_uint256",
+                    "typeString": "uint256"
+                  },
+                  "typeName": {
+                    "id": 1198,
+                    "name": "uint256",
+                    "nodeType": "ElementaryTypeName",
+                    "src": "30829:7:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_uint256",
+                      "typeString": "uint256"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                }
+              ],
+              "src": "30814:31:1"
+            },
+            "returnParameters": {
+              "id": 1201,
+              "nodeType": "ParameterList",
+              "parameters": [],
+              "src": "30854:0:1"
+            },
+            "scope": 1302,
+            "src": "30773:1128:1",
+            "stateMutability": "nonpayable",
+            "superFunction": null,
+            "visibility": "private"
+          },
+          {
+            "body": {
+              "id": 1300,
+              "nodeType": "Block",
+              "src": "32260:993:1",
+              "statements": [
+                {
+                  "assignments": [
+                    1258
+                  ],
+                  "declarations": [
+                    {
+                      "constant": false,
+                      "id": 1258,
+                      "name": "lastTokenIndex",
+                      "nodeType": "VariableDeclaration",
+                      "scope": 1300,
+                      "src": "32438:22:1",
+                      "stateVariable": false,
+                      "storageLocation": "default",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_uint256",
+                        "typeString": "uint256"
+                      },
+                      "typeName": {
+                        "id": 1257,
+                        "name": "uint256",
+                        "nodeType": "ElementaryTypeName",
+                        "src": "32438:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      },
+                      "value": null,
+                      "visibility": "internal"
+                    }
+                  ],
+                  "id": 1264,
+                  "initialValue": {
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+                    "arguments": [
+                      {
+                        "argumentTypes": null,
+                        "hexValue": "31",
+                        "id": 1262,
+                        "isConstant": false,
+                        "isLValue": false,
+                        "isPure": true,
+                        "kind": "number",
+                        "lValueRequested": false,
+                        "nodeType": "Literal",
+                        "src": "32485:1:1",
+                        "subdenomination": null,
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_rational_1_by_1",
+                          "typeString": "int_const 1"
+                        },
+                        "value": "1"
+                      }
+                    ],
+                    "expression": {
+                      "argumentTypes": [
+                        {
+                          "typeIdentifier": "t_rational_1_by_1",
+                          "typeString": "int_const 1"
+                        }
+                      ],
+                      "expression": {
+                        "argumentTypes": null,
+                        "expression": {
+                          "argumentTypes": null,
+                          "id": 1259,
+                          "name": "_allTokens",
+                          "nodeType": "Identifier",
+                          "overloadedDeclarations": [],
+                          "referencedDeclaration": 988,
+                          "src": "32463:10:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_array$_t_uint256_$dyn_storage",
+                            "typeString": "uint256[] storage ref"
+                          }
+                        },
+                        "id": 1260,
+                        "isConstant": false,
+                        "isLValue": true,
+                        "isPure": false,
+                        "lValueRequested": false,
+                        "memberName": "length",
+                        "nodeType": "MemberAccess",
+                        "referencedDeclaration": null,
+                        "src": "32463:17:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      },
+                      "id": 1261,
+                      "isConstant": false,
+                      "isLValue": false,
+                      "isPure": false,
+                      "lValueRequested": false,
+                      "memberName": "sub",
+                      "nodeType": "MemberAccess",
+                      "referencedDeclaration": 190,
+                      "src": "32463:21:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_function_internal_pure$_t_uint256_$_t_uint256_$returns$_t_uint256_$bound_to$_t_uint256_$",
+                        "typeString": "function (uint256,uint256) pure returns (uint256)"
+                      }
+                    },
+                    "id": 1263,
+                    "isConstant": false,
+                    "isLValue": false,
+                    "isPure": false,
+                    "kind": "functionCall",
+                    "lValueRequested": false,
+                    "names": [],
+                    "nodeType": "FunctionCall",
+                    "src": "32463:24:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_uint256",
+                      "typeString": "uint256"
+                    }
+                  },
+                  "nodeType": "VariableDeclarationStatement",
+                  "src": "32438:49:1"
+                },
+                {
+                  "assignments": [
+                    1266
+                  ],
+                  "declarations": [
+                    {
+                      "constant": false,
+                      "id": 1266,
+                      "name": "tokenIndex",
+                      "nodeType": "VariableDeclaration",
+                      "scope": 1300,
+                      "src": "32497:18:1",
+                      "stateVariable": false,
+                      "storageLocation": "default",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_uint256",
+                        "typeString": "uint256"
+                      },
+                      "typeName": {
+                        "id": 1265,
+                        "name": "uint256",
+                        "nodeType": "ElementaryTypeName",
+                        "src": "32497:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      },
+                      "value": null,
+                      "visibility": "internal"
+                    }
+                  ],
+                  "id": 1270,
+                  "initialValue": {
+                    "argumentTypes": null,
+                    "baseExpression": {
+                      "argumentTypes": null,
+                      "id": 1267,
+                      "name": "_allTokensIndex",
+                      "nodeType": "Identifier",
+                      "overloadedDeclarations": [],
+                      "referencedDeclaration": 992,
+                      "src": "32518:15:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_mapping$_t_uint256_$_t_uint256_$",
+                        "typeString": "mapping(uint256 => uint256)"
+                      }
+                    },
+                    "id": 1269,
+                    "indexExpression": {
+                      "argumentTypes": null,
+                      "id": 1268,
+                      "name": "tokenId",
+                      "nodeType": "Identifier",
+                      "overloadedDeclarations": [],
+                      "referencedDeclaration": 1254,
+                      "src": "32534:7:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_uint256",
+                        "typeString": "uint256"
+                      }
+                    },
+                    "isConstant": false,
+                    "isLValue": true,
+                    "isPure": false,
+                    "lValueRequested": false,
+                    "nodeType": "IndexAccess",
+                    "src": "32518:24:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_uint256",
+                      "typeString": "uint256"
+                    }
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+                        "src": "36278:5:1",
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+                          "isPure": false,
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+                          "nodeType": "UnaryOperation",
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+                          "prefix": true,
+                          "src": "36409:26:1",
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+                              "name": "_tokenURIs",
+                              "nodeType": "Identifier",
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+                              "src": "36416:10:1",
+                              "typeDescriptions": {
+                                "typeIdentifier": "t_mapping$_t_uint256_$_t_string_storage_$",
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+                              "id": 1440,
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+                              "src": "36427:7:1",
+                              "typeDescriptions": {
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+                                "typeString": "uint256"
+                              }
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+                            "nodeType": "IndexAccess",
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+                            "typeString": "tuple()"
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+        "literals": [
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+        "src": "36518:23:1"
+      },
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+              "name": "ERC721",
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+              "src": "36838:6:1",
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+              "src": "36846:16:1",
+              "typeDescriptions": {
+                "typeIdentifier": "t_contract$_ERC721Enumerable_$1302",
+                "typeString": "contract ERC721Enumerable"
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+            },
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+            "nodeType": "InheritanceSpecifier",
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+              "nodeType": "UserDefinedTypeName",
+              "referencedDeclaration": 1448,
+              "src": "36864:14:1",
+              "typeDescriptions": {
+                "typeIdentifier": "t_contract$_ERC721Metadata_$1448",
+                "typeString": "contract ERC721Metadata"
+              }
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+            "nodeType": "InheritanceSpecifier",
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+        "contractKind": "contract",
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+          386,
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+        "nodeType": "ContractDefinition",
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+                    "name": "bytes",
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+          }
+        ],
+        "scope": 1469,
+        "src": "972:1826:1"
+      },
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+        "id": 125,
+        "literals": [
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+          ".0"
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+        "src": "2867:23:1"
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+        "contractDependencies": [],
+        "contractKind": "contract",
+        "documentation": "@title ERC721 token receiver interface\n@dev Interface for any contract that wants to support safeTransfers\nfrom ERC721 asset contracts.",
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+        "id": 139,
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+                      "typeString": "tuple()"
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+                        "src": "28903:17:1",
+                        "typeDescriptions": {
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+                          "typeString": "uint256"
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+                      "src": "28903:26:1",
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+                        "typeString": "uint256"
+                      }
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+                      "kind": "number",
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+                      "nodeType": "Literal",
+                      "src": "28932:1:1",
+                      "subdenomination": null,
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_rational_0_by_1",
+                        "typeString": "int_const 0"
+                      },
+                      "value": "0"
+                    },
+                    "src": "28903:30:1",
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+                      "typeIdentifier": "t_uint256",
+                      "typeString": "uint256"
+                    }
+                  },
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+                        "id": 1135,
+                        "name": "tokenId",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 1113,
+                        "src": "28981:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      }
+                    ],
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+                      "argumentTypes": [
+                        {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      ],
+                      "id": 1134,
+                      "name": "_removeTokenFromAllTokensEnumeration",
+                      "nodeType": "Identifier",
+                      "overloadedDeclarations": [],
+                      "referencedDeclaration": 1301,
+                      "src": "28944:36:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_function_internal_nonpayable$_t_uint256_$returns$__$",
+                        "typeString": "function (uint256)"
+                      }
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+                    "kind": "functionCall",
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+                  "id": 1137,
+                  "nodeType": "ExpressionStatement",
+                  "src": "28944:45:1"
+                }
+              ]
+            },
+            "documentation": "@dev Internal function to burn a specific token.\nReverts if the token does not exist.\nDeprecated, use _burn(uint256) instead.\n@param owner owner of the token to burn\n@param tokenId uint256 ID of the token being burned",
+            "id": 1139,
+            "implemented": true,
+            "kind": "function",
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+            "name": "_burn",
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+              "nodeType": "ParameterList",
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+                  "id": 1111,
+                  "name": "owner",
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+                  "scope": 1139,
+                  "src": "28647:13:1",
+                  "stateVariable": false,
+                  "storageLocation": "default",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_address",
+                    "typeString": "address"
+                  },
+                  "typeName": {
+                    "id": 1110,
+                    "name": "address",
+                    "nodeType": "ElementaryTypeName",
+                    "src": "28647:7:1",
+                    "stateMutability": "nonpayable",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_address",
+                      "typeString": "address"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                },
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+                  "constant": false,
+                  "id": 1113,
+                  "name": "tokenId",
+                  "nodeType": "VariableDeclaration",
+                  "scope": 1139,
+                  "src": "28662:15:1",
+                  "stateVariable": false,
+                  "storageLocation": "default",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_uint256",
+                    "typeString": "uint256"
+                  },
+                  "typeName": {
+                    "id": 1112,
+                    "name": "uint256",
+                    "nodeType": "ElementaryTypeName",
+                    "src": "28662:7:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_uint256",
+                      "typeString": "uint256"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                }
+              ],
+              "src": "28646:32:1"
+            },
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+              "nodeType": "ParameterList",
+              "parameters": [],
+              "src": "28688:0:1"
+            },
+            "scope": 1302,
+            "src": "28632:364:1",
+            "stateMutability": "nonpayable",
+            "superFunction": 811,
+            "visibility": "internal"
+          },
+          {
+            "body": {
+              "id": 1151,
+              "nodeType": "Block",
+              "src": "29282:43:1",
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+                  "expression": {
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+                    "baseExpression": {
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+                      "id": 1147,
+                      "name": "_ownedTokens",
+                      "nodeType": "Identifier",
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+                      "referencedDeclaration": 981,
+                      "src": "29299:12:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_mapping$_t_address_$_t_array$_t_uint256_$dyn_storage_$",
+                        "typeString": "mapping(address => uint256[] storage ref)"
+                      }
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+                      "name": "owner",
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+                      "referencedDeclaration": 1141,
+                      "src": "29312:5:1",
+                      "typeDescriptions": {
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+                    "isLValue": true,
+                    "isPure": false,
+                    "lValueRequested": false,
+                    "nodeType": "IndexAccess",
+                    "src": "29299:19:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_array$_t_uint256_$dyn_storage",
+                      "typeString": "uint256[] storage ref"
+                    }
+                  },
+                  "functionReturnParameters": 1146,
+                  "id": 1150,
+                  "nodeType": "Return",
+                  "src": "29292:26:1"
+                }
+              ]
+            },
+            "documentation": "@dev Gets the list of token IDs of the requested owner.\n@param owner address owning the tokens\n@return uint256[] List of token IDs owned by the requested address",
+            "id": 1152,
+            "implemented": true,
+            "kind": "function",
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+            "name": "_tokensOfOwner",
+            "nodeType": "FunctionDefinition",
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+                  "src": "29225:13:1",
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+                  "storageLocation": "default",
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+                    "typeString": "address"
+                  },
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+                    "name": "address",
+                    "nodeType": "ElementaryTypeName",
+                    "src": "29225:7:1",
+                    "stateMutability": "nonpayable",
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+                      "typeIdentifier": "t_address",
+                      "typeString": "address"
+                    }
+                  },
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+                  "visibility": "internal"
+                }
+              ],
+              "src": "29224:15:1"
+            },
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+              "nodeType": "ParameterList",
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+                  "name": "",
+                  "nodeType": "VariableDeclaration",
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+                  "src": "29263:17:1",
+                  "stateVariable": false,
+                  "storageLocation": "storage",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_array$_t_uint256_$dyn_storage_ptr",
+                    "typeString": "uint256[]"
+                  },
+                  "typeName": {
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+                      "name": "uint256",
+                      "nodeType": "ElementaryTypeName",
+                      "src": "29263:7:1",
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+                        "typeIdentifier": "t_uint256",
+                        "typeString": "uint256"
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+                    "nodeType": "ArrayTypeName",
+                    "src": "29263:9:1",
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+                    }
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+                  "visibility": "internal"
+                }
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+              "src": "29262:19:1"
+            },
+            "scope": 1302,
+            "src": "29201:124:1",
+            "stateMutability": "view",
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+            "visibility": "internal"
+          },
+          {
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+              "nodeType": "Block",
+              "src": "29693:109:1",
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+                        "referencedDeclaration": 985,
+                        "src": "29703:17:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_mapping$_t_uint256_$_t_uint256_$",
+                          "typeString": "mapping(uint256 => uint256)"
+                        }
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+                        "nodeType": "Identifier",
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+                        "src": "29721:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
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+                      "lValueRequested": true,
+                      "nodeType": "IndexAccess",
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+                      "typeDescriptions": {
+                        "typeIdentifier": "t_uint256",
+                        "typeString": "uint256"
+                      }
+                    },
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+                      "expression": {
+                        "argumentTypes": null,
+                        "baseExpression": {
+                          "argumentTypes": null,
+                          "id": 1162,
+                          "name": "_ownedTokens",
+                          "nodeType": "Identifier",
+                          "overloadedDeclarations": [],
+                          "referencedDeclaration": 981,
+                          "src": "29732:12:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_mapping$_t_address_$_t_array$_t_uint256_$dyn_storage_$",
+                            "typeString": "mapping(address => uint256[] storage ref)"
+                          }
+                        },
+                        "id": 1164,
+                        "indexExpression": {
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+                          "id": 1163,
+                          "name": "to",
+                          "nodeType": "Identifier",
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+                          "referencedDeclaration": 1154,
+                          "src": "29745:2:1",
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+                            "typeString": "address"
+                          }
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+                        "nodeType": "IndexAccess",
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+                          "typeString": "uint256[] storage ref"
+                        }
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+                      "lValueRequested": false,
+                      "memberName": "length",
+                      "nodeType": "MemberAccess",
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+                      "src": "29732:23:1",
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+                        "typeIdentifier": "t_uint256",
+                        "typeString": "uint256"
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+                    "src": "29703:52:1",
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+                      "typeIdentifier": "t_uint256",
+                      "typeString": "uint256"
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+                },
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+                        "referencedDeclaration": 1156,
+                        "src": "29787:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
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+                    ],
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+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
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+                        "baseExpression": {
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+                          "id": 1168,
+                          "name": "_ownedTokens",
+                          "nodeType": "Identifier",
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+                          "referencedDeclaration": 981,
+                          "src": "29765:12:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_mapping$_t_address_$_t_array$_t_uint256_$dyn_storage_$",
+                            "typeString": "mapping(address => uint256[] storage ref)"
+                          }
+                        },
+                        "id": 1170,
+                        "indexExpression": {
+                          "argumentTypes": null,
+                          "id": 1169,
+                          "name": "to",
+                          "nodeType": "Identifier",
+                          "overloadedDeclarations": [],
+                          "referencedDeclaration": 1154,
+                          "src": "29778:2:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_address",
+                            "typeString": "address"
+                          }
+                        },
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+                        "isLValue": true,
+                        "isPure": false,
+                        "lValueRequested": false,
+                        "nodeType": "IndexAccess",
+                        "src": "29765:16:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_array$_t_uint256_$dyn_storage",
+                          "typeString": "uint256[] storage ref"
+                        }
+                      },
+                      "id": 1171,
+                      "isConstant": false,
+                      "isLValue": false,
+                      "isPure": false,
+                      "lValueRequested": false,
+                      "memberName": "push",
+                      "nodeType": "MemberAccess",
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+                      "src": "29765:21:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_function_arraypush_nonpayable$_t_uint256_$returns$_t_uint256_$",
+                        "typeString": "function (uint256) returns (uint256)"
+                      }
+                    },
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+                    "isConstant": false,
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+                    "isPure": false,
+                    "kind": "functionCall",
+                    "lValueRequested": false,
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+                    "src": "29765:30:1",
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+                      "typeIdentifier": "t_uint256",
+                      "typeString": "uint256"
+                    }
+                  },
+                  "id": 1174,
+                  "nodeType": "ExpressionStatement",
+                  "src": "29765:30:1"
+                }
+              ]
+            },
+            "documentation": "@dev Private function to add a token to this extension's ownership-tracking data structures.\n@param to address representing the new owner of the given token ID\n@param tokenId uint256 ID of the token to be added to the tokens list of the given address",
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+            "kind": "function",
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+            "name": "_addTokenToOwnerEnumeration",
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+              "nodeType": "ParameterList",
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+                  "storageLocation": "default",
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+                    "typeIdentifier": "t_address",
+                    "typeString": "address"
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+                    "id": 1153,
+                    "name": "address",
+                    "nodeType": "ElementaryTypeName",
+                    "src": "29656:7:1",
+                    "stateMutability": "nonpayable",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_address",
+                      "typeString": "address"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                },
+                {
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+                  "scope": 1176,
+                  "src": "29668:15:1",
+                  "stateVariable": false,
+                  "storageLocation": "default",
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+                    "nodeType": "ElementaryTypeName",
+                    "src": "29668:7:1",
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+                      "typeString": "uint256"
+                    }
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+                  "visibility": "internal"
+                }
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+              "src": "29655:29:1"
+            },
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+              "src": "29693:0:1"
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+            "src": "29619:183:1",
+            "stateMutability": "nonpayable",
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+            "visibility": "private"
+          },
+          {
+            "body": {
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+              "nodeType": "Block",
+              "src": "30063:95:1",
+              "statements": [
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+                    "id": 1186,
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+                    "isLValue": false,
+                    "isPure": false,
+                    "lValueRequested": false,
+                    "leftHandSide": {
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+                      "baseExpression": {
+                        "argumentTypes": null,
+                        "id": 1181,
+                        "name": "_allTokensIndex",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 992,
+                        "src": "30073:15:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_mapping$_t_uint256_$_t_uint256_$",
+                          "typeString": "mapping(uint256 => uint256)"
+                        }
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+                      "id": 1183,
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+                        "id": 1182,
+                        "name": "tokenId",
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+                        "nodeType": "ExpressionStatement",
+                        "src": "31484:43:1"
+                      }
+                    ]
+                  }
+                },
+                {
+                  "expression": {
+                    "argumentTypes": null,
+                    "id": 1249,
+                    "isConstant": false,
+                    "isLValue": false,
+                    "isPure": false,
+                    "lValueRequested": false,
+                    "nodeType": "UnaryOperation",
+                    "operator": "--",
+                    "prefix": false,
+                    "src": "31658:27:1",
+                    "subExpression": {
+                      "argumentTypes": null,
+                      "expression": {
+                        "argumentTypes": null,
+                        "baseExpression": {
+                          "argumentTypes": null,
+                          "id": 1245,
+                          "name": "_ownedTokens",
+                          "nodeType": "Identifier",
+                          "overloadedDeclarations": [],
+                          "referencedDeclaration": 981,
+                          "src": "31658:12:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_mapping$_t_address_$_t_array$_t_uint256_$dyn_storage_$",
+                            "typeString": "mapping(address => uint256[] storage ref)"
+                          }
+                        },
+                        "id": 1247,
+                        "indexExpression": {
+                          "argumentTypes": null,
+                          "id": 1246,
+                          "name": "from",
+                          "nodeType": "Identifier",
+                          "overloadedDeclarations": [],
+                          "referencedDeclaration": 1197,
+                          "src": "31671:4:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_address",
+                            "typeString": "address"
+                          }
+                        },
+                        "isConstant": false,
+                        "isLValue": true,
+                        "isPure": false,
+                        "lValueRequested": false,
+                        "nodeType": "IndexAccess",
+                        "src": "31658:18:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_array$_t_uint256_$dyn_storage",
+                          "typeString": "uint256[] storage ref"
+                        }
+                      },
+                      "id": 1248,
+                      "isConstant": false,
+                      "isLValue": true,
+                      "isPure": false,
+                      "lValueRequested": true,
+                      "memberName": "length",
+                      "nodeType": "MemberAccess",
+                      "referencedDeclaration": null,
+                      "src": "31658:25:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_uint256",
+                        "typeString": "uint256"
+                      }
+                    },
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_uint256",
+                      "typeString": "uint256"
+                    }
+                  },
+                  "id": 1250,
+                  "nodeType": "ExpressionStatement",
+                  "src": "31658:27:1"
+                }
+              ]
+            },
+            "documentation": "@dev Private function to remove a token from this extension's ownership-tracking data structures. Note that\nwhile the token is not assigned a new owner, the _ownedTokensIndex mapping is _not_ updated: this allows for\ngas optimizations e.g. when performing a transfer operation (avoiding double writes).\nThis has O(1) time complexity, but alters the order of the _ownedTokens array.\n@param from address representing the previous owner of the given token ID\n@param tokenId uint256 ID of the token to be removed from the tokens list of the given address",
+            "id": 1252,
+            "implemented": true,
+            "kind": "function",
+            "modifiers": [],
+            "name": "_removeTokenFromOwnerEnumeration",
+            "nodeType": "FunctionDefinition",
+            "parameters": {
+              "id": 1200,
+              "nodeType": "ParameterList",
+              "parameters": [
+                {
+                  "constant": false,
+                  "id": 1197,
+                  "name": "from",
+                  "nodeType": "VariableDeclaration",
+                  "scope": 1252,
+                  "src": "30815:12:1",
+                  "stateVariable": false,
+                  "storageLocation": "default",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_address",
+                    "typeString": "address"
+                  },
+                  "typeName": {
+                    "id": 1196,
+                    "name": "address",
+                    "nodeType": "ElementaryTypeName",
+                    "src": "30815:7:1",
+                    "stateMutability": "nonpayable",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_address",
+                      "typeString": "address"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                },
+                {
+                  "constant": false,
+                  "id": 1199,
+                  "name": "tokenId",
+                  "nodeType": "VariableDeclaration",
+                  "scope": 1252,
+                  "src": "30829:15:1",
+                  "stateVariable": false,
+                  "storageLocation": "default",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_uint256",
+                    "typeString": "uint256"
+                  },
+                  "typeName": {
+                    "id": 1198,
+                    "name": "uint256",
+                    "nodeType": "ElementaryTypeName",
+                    "src": "30829:7:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_uint256",
+                      "typeString": "uint256"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                }
+              ],
+              "src": "30814:31:1"
+            },
+            "returnParameters": {
+              "id": 1201,
+              "nodeType": "ParameterList",
+              "parameters": [],
+              "src": "30854:0:1"
+            },
+            "scope": 1302,
+            "src": "30773:1128:1",
+            "stateMutability": "nonpayable",
+            "superFunction": null,
+            "visibility": "private"
+          },
+          {
+            "body": {
+              "id": 1300,
+              "nodeType": "Block",
+              "src": "32260:993:1",
+              "statements": [
+                {
+                  "assignments": [
+                    1258
+                  ],
+                  "declarations": [
+                    {
+                      "constant": false,
+                      "id": 1258,
+                      "name": "lastTokenIndex",
+                      "nodeType": "VariableDeclaration",
+                      "scope": 1300,
+                      "src": "32438:22:1",
+                      "stateVariable": false,
+                      "storageLocation": "default",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_uint256",
+                        "typeString": "uint256"
+                      },
+                      "typeName": {
+                        "id": 1257,
+                        "name": "uint256",
+                        "nodeType": "ElementaryTypeName",
+                        "src": "32438:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      },
+                      "value": null,
+                      "visibility": "internal"
+                    }
+                  ],
+                  "id": 1264,
+                  "initialValue": {
+                    "argumentTypes": null,
+                    "arguments": [
+                      {
+                        "argumentTypes": null,
+                        "hexValue": "31",
+                        "id": 1262,
+                        "isConstant": false,
+                        "isLValue": false,
+                        "isPure": true,
+                        "kind": "number",
+                        "lValueRequested": false,
+                        "nodeType": "Literal",
+                        "src": "32485:1:1",
+                        "subdenomination": null,
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_rational_1_by_1",
+                          "typeString": "int_const 1"
+                        },
+                        "value": "1"
+                      }
+                    ],
+                    "expression": {
+                      "argumentTypes": [
+                        {
+                          "typeIdentifier": "t_rational_1_by_1",
+                          "typeString": "int_const 1"
+                        }
+                      ],
+                      "expression": {
+                        "argumentTypes": null,
+                        "expression": {
+                          "argumentTypes": null,
+                          "id": 1259,
+                          "name": "_allTokens",
+                          "nodeType": "Identifier",
+                          "overloadedDeclarations": [],
+                          "referencedDeclaration": 988,
+                          "src": "32463:10:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_array$_t_uint256_$dyn_storage",
+                            "typeString": "uint256[] storage ref"
+                          }
+                        },
+                        "id": 1260,
+                        "isConstant": false,
+                        "isLValue": true,
+                        "isPure": false,
+                        "lValueRequested": false,
+                        "memberName": "length",
+                        "nodeType": "MemberAccess",
+                        "referencedDeclaration": null,
+                        "src": "32463:17:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      },
+                      "id": 1261,
+                      "isConstant": false,
+                      "isLValue": false,
+                      "isPure": false,
+                      "lValueRequested": false,
+                      "memberName": "sub",
+                      "nodeType": "MemberAccess",
+                      "referencedDeclaration": 190,
+                      "src": "32463:21:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_function_internal_pure$_t_uint256_$_t_uint256_$returns$_t_uint256_$bound_to$_t_uint256_$",
+                        "typeString": "function (uint256,uint256) pure returns (uint256)"
+                      }
+                    },
+                    "id": 1263,
+                    "isConstant": false,
+                    "isLValue": false,
+                    "isPure": false,
+                    "kind": "functionCall",
+                    "lValueRequested": false,
+                    "names": [],
+                    "nodeType": "FunctionCall",
+                    "src": "32463:24:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_uint256",
+                      "typeString": "uint256"
+                    }
+                  },
+                  "nodeType": "VariableDeclarationStatement",
+                  "src": "32438:49:1"
+                },
+                {
+                  "assignments": [
+                    1266
+                  ],
+                  "declarations": [
+                    {
+                      "constant": false,
+                      "id": 1266,
+                      "name": "tokenIndex",
+                      "nodeType": "VariableDeclaration",
+                      "scope": 1300,
+                      "src": "32497:18:1",
+                      "stateVariable": false,
+                      "storageLocation": "default",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_uint256",
+                        "typeString": "uint256"
+                      },
+                      "typeName": {
+                        "id": 1265,
+                        "name": "uint256",
+                        "nodeType": "ElementaryTypeName",
+                        "src": "32497:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      },
+                      "value": null,
+                      "visibility": "internal"
+                    }
+                  ],
+                  "id": 1270,
+                  "initialValue": {
+                    "argumentTypes": null,
+                    "baseExpression": {
+                      "argumentTypes": null,
+                      "id": 1267,
+                      "name": "_allTokensIndex",
+                      "nodeType": "Identifier",
+                      "overloadedDeclarations": [],
+                      "referencedDeclaration": 992,
+                      "src": "32518:15:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_mapping$_t_uint256_$_t_uint256_$",
+                        "typeString": "mapping(uint256 => uint256)"
+                      }
+                    },
+                    "id": 1269,
+                    "indexExpression": {
+                      "argumentTypes": null,
+                      "id": 1268,
+                      "name": "tokenId",
+                      "nodeType": "Identifier",
+                      "overloadedDeclarations": [],
+                      "referencedDeclaration": 1254,
+                      "src": "32534:7:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_uint256",
+                        "typeString": "uint256"
+                      }
+                    },
+                    "isConstant": false,
+                    "isLValue": true,
+                    "isPure": false,
+                    "lValueRequested": false,
+                    "nodeType": "IndexAccess",
+                    "src": "32518:24:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_uint256",
+                      "typeString": "uint256"
+                    }
+                  },
+                  "nodeType": "VariableDeclarationStatement",
+                  "src": "32497:45:1"
+                },
+                {
+                  "assignments": [
+                    1272
+                  ],
+                  "declarations": [
+                    {
+                      "constant": false,
+                      "id": 1272,
+                      "name": "lastTokenId",
+                      "nodeType": "VariableDeclaration",
+                      "scope": 1300,
+                      "src": "32864:19:1",
+                      "stateVariable": false,
+                      "storageLocation": "default",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_uint256",
+                        "typeString": "uint256"
+                      },
+                      "typeName": {
+                        "id": 1271,
+                        "name": "uint256",
+                        "nodeType": "ElementaryTypeName",
+                        "src": "32864:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      },
+                      "value": null,
+                      "visibility": "internal"
+                    }
+                  ],
+                  "id": 1276,
+                  "initialValue": {
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+                    "baseExpression": {
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+                      "id": 1273,
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+                      "nodeType": "Identifier",
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+                      "src": "32886:10:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_array$_t_uint256_$dyn_storage",
+                        "typeString": "uint256[] storage ref"
+                      }
+                    },
+                    "id": 1275,
+                    "indexExpression": {
+                      "argumentTypes": null,
+                      "id": 1274,
+                      "name": "lastTokenIndex",
+                      "nodeType": "Identifier",
+                      "overloadedDeclarations": [],
+                      "referencedDeclaration": 1258,
+                      "src": "32897:14:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_uint256",
+                        "typeString": "uint256"
+                      }
+                    },
+                    "isConstant": false,
+                    "isLValue": true,
+                    "isPure": false,
+                    "lValueRequested": false,
+                    "nodeType": "IndexAccess",
+                    "src": "32886:26:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_uint256",
+                      "typeString": "uint256"
+                    }
+                  },
+                  "nodeType": "VariableDeclarationStatement",
+                  "src": "32864:48:1"
+                },
+                {
+                  "expression": {
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+                    "id": 1281,
+                    "isConstant": false,
+                    "isLValue": false,
+                    "isPure": false,
+                    "lValueRequested": false,
+                    "leftHandSide": {
+                      "argumentTypes": null,
+                      "baseExpression": {
+                        "argumentTypes": null,
+                        "id": 1277,
+                        "name": "_allTokens",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 988,
+                        "src": "32923:10:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_array$_t_uint256_$dyn_storage",
+                          "typeString": "uint256[] storage ref"
+                        }
+                      },
+                      "id": 1279,
+                      "indexExpression": {
+                        "argumentTypes": null,
+                        "id": 1278,
+                        "name": "tokenIndex",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 1266,
+                        "src": "32934:10:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      },
+                      "isConstant": false,
+                      "isLValue": true,
+                      "isPure": false,
+                      "lValueRequested": true,
+                      "nodeType": "IndexAccess",
+                      "src": "32923:22:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_uint256",
+                        "typeString": "uint256"
+                      }
+                    },
+                    "nodeType": "Assignment",
+                    "operator": "=",
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+                      "argumentTypes": null,
+                      "id": 1280,
+                      "name": "lastTokenId",
+                      "nodeType": "Identifier",
+                      "overloadedDeclarations": [],
+                      "referencedDeclaration": 1272,
+                      "src": "32948:11:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_uint256",
+                        "typeString": "uint256"
+                      }
+                    },
+                    "src": "32923:36:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_uint256",
+                      "typeString": "uint256"
+                    }
+                  },
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+                  "src": "32923:36:1"
+                },
+                {
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+                    "id": 1287,
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+                    "isLValue": false,
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+                    "leftHandSide": {
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+                      "baseExpression": {
+                        "argumentTypes": null,
+                        "id": 1283,
+                        "name": "_allTokensIndex",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 992,
+                        "src": "33027:15:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_mapping$_t_uint256_$_t_uint256_$",
+                          "typeString": "mapping(uint256 => uint256)"
+                        }
+                      },
+                      "id": 1285,
+                      "indexExpression": {
+                        "argumentTypes": null,
+                        "id": 1284,
+                        "name": "lastTokenId",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 1272,
+                        "src": "33043:11:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
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+                        "typeString": "uint256"
+                      }
+                    },
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+                      "src": "33058:10:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_uint256",
+                        "typeString": "uint256"
+                      }
+                    },
+                    "src": "33027:41:1",
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+                      "typeIdentifier": "t_uint256",
+                      "typeString": "uint256"
+                    }
+                  },
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+                  "nodeType": "ExpressionStatement",
+                  "src": "33027:41:1"
+                },
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+                    "isPure": false,
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+                    "operator": "--",
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+                    "src": "33189:19:1",
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+                      "expression": {
+                        "argumentTypes": null,
+                        "id": 1289,
+                        "name": "_allTokens",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 988,
+                        "src": "33189:10:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_array$_t_uint256_$dyn_storage",
+                          "typeString": "uint256[] storage ref"
+                        }
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+                      "id": 1291,
+                      "isConstant": false,
+                      "isLValue": true,
+                      "isPure": false,
+                      "lValueRequested": true,
+                      "memberName": "length",
+                      "nodeType": "MemberAccess",
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+                      "src": "33189:17:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_uint256",
+                        "typeString": "uint256"
+                      }
+                    },
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_uint256",
+                      "typeString": "uint256"
+                    }
+                  },
+                  "id": 1293,
+                  "nodeType": "ExpressionStatement",
+                  "src": "33189:19:1"
+                },
+                {
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+                    "id": 1298,
+                    "isConstant": false,
+                    "isLValue": false,
+                    "isPure": false,
+                    "lValueRequested": false,
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+                      "baseExpression": {
+                        "argumentTypes": null,
+                        "id": 1294,
+                        "name": "_allTokensIndex",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 992,
+                        "src": "33218:15:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_mapping$_t_uint256_$_t_uint256_$",
+                          "typeString": "mapping(uint256 => uint256)"
+                        }
+                      },
+                      "id": 1296,
+                      "indexExpression": {
+                        "argumentTypes": null,
+                        "id": 1295,
+                        "name": "tokenId",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 1254,
+                        "src": "33234:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      },
+                      "isConstant": false,
+                      "isLValue": true,
+                      "isPure": false,
+                      "lValueRequested": true,
+                      "nodeType": "IndexAccess",
+                      "src": "33218:24:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_uint256",
+                        "typeString": "uint256"
+                      }
+                    },
+                    "nodeType": "Assignment",
+                    "operator": "=",
+                    "rightHandSide": {
+                      "argumentTypes": null,
+                      "hexValue": "30",
+                      "id": 1297,
+                      "isConstant": false,
+                      "isLValue": false,
+                      "isPure": true,
+                      "kind": "number",
+                      "lValueRequested": false,
+                      "nodeType": "Literal",
+                      "src": "33245:1:1",
+                      "subdenomination": null,
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_rational_0_by_1",
+                        "typeString": "int_const 0"
+                      },
+                      "value": "0"
+                    },
+                    "src": "33218:28:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_uint256",
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+                    }
+                  },
+                  "id": 1299,
+                  "nodeType": "ExpressionStatement",
+                  "src": "33218:28:1"
+                }
+              ]
+            },
+            "documentation": "@dev Private function to remove a token from this extension's token tracking data structures.\nThis has O(1) time complexity, but alters the order of the _allTokens array.\n@param tokenId uint256 ID of the token to be removed from the tokens list",
+            "id": 1301,
+            "implemented": true,
+            "kind": "function",
+            "modifiers": [],
+            "name": "_removeTokenFromAllTokensEnumeration",
+            "nodeType": "FunctionDefinition",
+            "parameters": {
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+              "nodeType": "ParameterList",
+              "parameters": [
+                {
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+                  "id": 1254,
+                  "name": "tokenId",
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+                  "scope": 1301,
+                  "src": "32235:15:1",
+                  "stateVariable": false,
+                  "storageLocation": "default",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_uint256",
+                    "typeString": "uint256"
+                  },
+                  "typeName": {
+                    "id": 1253,
+                    "name": "uint256",
+                    "nodeType": "ElementaryTypeName",
+                    "src": "32235:7:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_uint256",
+                      "typeString": "uint256"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                }
+              ],
+              "src": "32234:17:1"
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+                              "typeString": "string storage ref"
+                            }
+                          ],
+                          "id": 1431,
+                          "isConstant": false,
+                          "isLValue": false,
+                          "isPure": true,
+                          "lValueRequested": false,
+                          "nodeType": "ElementaryTypeNameExpression",
+                          "src": "36355:5:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_type$_t_bytes_storage_ptr_$",
+                            "typeString": "type(bytes storage pointer)"
+                          },
+                          "typeName": "bytes"
+                        },
+                        "id": 1435,
+                        "isConstant": false,
+                        "isLValue": false,
+                        "isPure": false,
+                        "kind": "typeConversion",
+                        "lValueRequested": false,
+                        "names": [],
+                        "nodeType": "FunctionCall",
+                        "src": "36355:26:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_bytes_storage_ptr",
+                          "typeString": "bytes storage pointer"
+                        }
+                      },
+                      "id": 1436,
+                      "isConstant": false,
+                      "isLValue": true,
+                      "isPure": false,
+                      "lValueRequested": false,
+                      "memberName": "length",
+                      "nodeType": "MemberAccess",
+                      "referencedDeclaration": null,
+                      "src": "36355:33:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_uint256",
+                        "typeString": "uint256"
+                      }
+                    },
+                    "nodeType": "BinaryOperation",
+                    "operator": "!=",
+                    "rightExpression": {
+                      "argumentTypes": null,
+                      "hexValue": "30",
+                      "id": 1437,
+                      "isConstant": false,
+                      "isLValue": false,
+                      "isPure": true,
+                      "kind": "number",
+                      "lValueRequested": false,
+                      "nodeType": "Literal",
+                      "src": "36392:1:1",
+                      "subdenomination": null,
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_rational_0_by_1",
+                        "typeString": "int_const 0"
+                      },
+                      "value": "0"
+                    },
+                    "src": "36355:38:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_bool",
+                      "typeString": "bool"
+                    }
+                  },
+                  "falseBody": null,
+                  "id": 1445,
+                  "nodeType": "IfStatement",
+                  "src": "36351:95:1",
+                  "trueBody": {
+                    "id": 1444,
+                    "nodeType": "Block",
+                    "src": "36395:51:1",
+                    "statements": [
+                      {
+                        "expression": {
+                          "argumentTypes": null,
+                          "id": 1442,
+                          "isConstant": false,
+                          "isLValue": false,
+                          "isPure": false,
+                          "lValueRequested": false,
+                          "nodeType": "UnaryOperation",
+                          "operator": "delete",
+                          "prefix": true,
+                          "src": "36409:26:1",
+                          "subExpression": {
+                            "argumentTypes": null,
+                            "baseExpression": {
+                              "argumentTypes": null,
+                              "id": 1439,
+                              "name": "_tokenURIs",
+                              "nodeType": "Identifier",
+                              "overloadedDeclarations": [],
+                              "referencedDeclaration": 1338,
+                              "src": "36416:10:1",
+                              "typeDescriptions": {
+                                "typeIdentifier": "t_mapping$_t_uint256_$_t_string_storage_$",
+                                "typeString": "mapping(uint256 => string storage ref)"
+                              }
+                            },
+                            "id": 1441,
+                            "indexExpression": {
+                              "argumentTypes": null,
+                              "id": 1440,
+                              "name": "tokenId",
+                              "nodeType": "Identifier",
+                              "overloadedDeclarations": [],
+                              "referencedDeclaration": 1421,
+                              "src": "36427:7:1",
+                              "typeDescriptions": {
+                                "typeIdentifier": "t_uint256",
+                                "typeString": "uint256"
+                              }
+                            },
+                            "isConstant": false,
+                            "isLValue": true,
+                            "isPure": false,
+                            "lValueRequested": true,
+                            "nodeType": "IndexAccess",
+                            "src": "36416:19:1",
+                            "typeDescriptions": {
+                              "typeIdentifier": "t_string_storage",
+                              "typeString": "string storage ref"
+                            }
+                          },
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_tuple$__$",
+                            "typeString": "tuple()"
+                          }
+                        },
+                        "id": 1443,
+                        "nodeType": "ExpressionStatement",
+                        "src": "36409:26:1"
+                      }
+                    ]
+                  }
+                }
+              ]
+            },
+            "documentation": "@dev Internal function to burn a specific token.\nReverts if the token does not exist.\nDeprecated, use _burn(uint256) instead.\n@param owner owner of the token to burn\n@param tokenId uint256 ID of the token being burned by the msg.sender",
+            "id": 1447,
+            "implemented": true,
+            "kind": "function",
+            "modifiers": [],
+            "name": "_burn",
+            "nodeType": "FunctionDefinition",
+            "parameters": {
+              "id": 1422,
+              "nodeType": "ParameterList",
+              "parameters": [
+                {
+                  "constant": false,
+                  "id": 1419,
+                  "name": "owner",
+                  "nodeType": "VariableDeclaration",
+                  "scope": 1447,
+                  "src": "36227:13:1",
+                  "stateVariable": false,
+                  "storageLocation": "default",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_address",
+                    "typeString": "address"
+                  },
+                  "typeName": {
+                    "id": 1418,
+                    "name": "address",
+                    "nodeType": "ElementaryTypeName",
+                    "src": "36227:7:1",
+                    "stateMutability": "nonpayable",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_address",
+                      "typeString": "address"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                },
+                {
+                  "constant": false,
+                  "id": 1421,
+                  "name": "tokenId",
+                  "nodeType": "VariableDeclaration",
+                  "scope": 1447,
+                  "src": "36242:15:1",
+                  "stateVariable": false,
+                  "storageLocation": "default",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_uint256",
+                    "typeString": "uint256"
+                  },
+                  "typeName": {
+                    "id": 1420,
+                    "name": "uint256",
+                    "nodeType": "ElementaryTypeName",
+                    "src": "36242:7:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_uint256",
+                      "typeString": "uint256"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                }
+              ],
+              "src": "36226:32:1"
+            },
+            "returnParameters": {
+              "id": 1423,
+              "nodeType": "ParameterList",
+              "parameters": [],
+              "src": "36268:0:1"
+            },
+            "scope": 1448,
+            "src": "36212:240:1",
+            "stateMutability": "nonpayable",
+            "superFunction": 811,
+            "visibility": "internal"
+          }
+        ],
+        "scope": 1469,
+        "src": "33817:2637:1"
+      },
+      {
+        "id": 1449,
+        "literals": [
+          "solidity",
+          "^",
+          "0.5",
+          ".0"
+        ],
+        "nodeType": "PragmaDirective",
+        "src": "36518:23:1"
+      },
+      {
+        "baseContracts": [
+          {
+            "arguments": null,
+            "baseName": {
+              "contractScope": null,
+              "id": 1450,
+              "name": "ERC721",
+              "nodeType": "UserDefinedTypeName",
+              "referencedDeclaration": 944,
+              "src": "36838:6:1",
+              "typeDescriptions": {
+                "typeIdentifier": "t_contract$_ERC721_$944",
+                "typeString": "contract ERC721"
+              }
+            },
+            "id": 1451,
+            "nodeType": "InheritanceSpecifier",
+            "src": "36838:6:1"
+          },
+          {
+            "arguments": null,
+            "baseName": {
+              "contractScope": null,
+              "id": 1452,
+              "name": "ERC721Enumerable",
+              "nodeType": "UserDefinedTypeName",
+              "referencedDeclaration": 1302,
+              "src": "36846:16:1",
+              "typeDescriptions": {
+                "typeIdentifier": "t_contract$_ERC721Enumerable_$1302",
+                "typeString": "contract ERC721Enumerable"
+              }
+            },
+            "id": 1453,
+            "nodeType": "InheritanceSpecifier",
+            "src": "36846:16:1"
+          },
+          {
+            "arguments": null,
+            "baseName": {
+              "contractScope": null,
+              "id": 1454,
+              "name": "ERC721Metadata",
+              "nodeType": "UserDefinedTypeName",
+              "referencedDeclaration": 1448,
+              "src": "36864:14:1",
+              "typeDescriptions": {
+                "typeIdentifier": "t_contract$_ERC721Metadata_$1448",
+                "typeString": "contract ERC721Metadata"
+              }
+            },
+            "id": 1455,
+            "nodeType": "InheritanceSpecifier",
+            "src": "36864:14:1"
+          }
+        ],
+        "contractDependencies": [
+          944,
+          969,
+          23,
+          124,
+          386,
+          1302,
+          1323,
+          1448
+        ],
+        "contractKind": "contract",
+        "documentation": "@title Full ERC721 Token\nThis implementation includes all the required and some optional functionality of the ERC721 standard\nMoreover, it includes approve all functionality using operator terminology\n@dev see https://eips.ethereum.org/EIPS/eip-721",
+        "fullyImplemented": true,
+        "id": 1468,
+        "linearizedBaseContracts": [
+          1468,
+          1448,
+          1323,
+          1302,
+          969,
+          944,
+          124,
+          386,
+          23
+        ],
+        "name": "ERC721Full",
+        "nodeType": "ContractDefinition",
+        "nodes": [
+          {
+            "body": {
+              "id": 1466,
+              "nodeType": "Block",
+              "src": "36976:64:1",
+              "statements": []
+            },
+            "documentation": null,
+            "id": 1467,
+            "implemented": true,
+            "kind": "constructor",
+            "modifiers": [
+              {
+                "arguments": [
+                  {
+                    "argumentTypes": null,
+                    "id": 1462,
+                    "name": "name",
+                    "nodeType": "Identifier",
+                    "overloadedDeclarations": [],
+                    "referencedDeclaration": 1457,
+                    "src": "36962:4:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_string_memory_ptr",
+                      "typeString": "string memory"
+                    }
+                  },
+                  {
+                    "argumentTypes": null,
+                    "id": 1463,
+                    "name": "symbol",
+                    "nodeType": "Identifier",
+                    "overloadedDeclarations": [],
+                    "referencedDeclaration": 1459,
+                    "src": "36968:6:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_string_memory_ptr",
+                      "typeString": "string memory"
+                    }
+                  }
+                ],
+                "id": 1464,
+                "modifierName": {
+                  "argumentTypes": null,
+                  "id": 1461,
+                  "name": "ERC721Metadata",
+                  "nodeType": "Identifier",
+                  "overloadedDeclarations": [],
+                  "referencedDeclaration": 1448,
+                  "src": "36947:14:1",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_type$_t_contract$_ERC721Metadata_$1448_$",
+                    "typeString": "type(contract ERC721Metadata)"
+                  }
+                },
+                "nodeType": "ModifierInvocation",
+                "src": "36947:28:1"
+              }
+            ],
+            "name": "",
+            "nodeType": "FunctionDefinition",
+            "parameters": {
+              "id": 1460,
+              "nodeType": "ParameterList",
+              "parameters": [
+                {
+                  "constant": false,
+                  "id": 1457,
+                  "name": "name",
+                  "nodeType": "VariableDeclaration",
+                  "scope": 1467,
+                  "src": "36898:18:1",
+                  "stateVariable": false,
+                  "storageLocation": "memory",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_string_memory_ptr",
+                    "typeString": "string"
+                  },
+                  "typeName": {
+                    "id": 1456,
+                    "name": "string",
+                    "nodeType": "ElementaryTypeName",
+                    "src": "36898:6:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_string_storage_ptr",
+                      "typeString": "string"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                },
+                {
+                  "constant": false,
+                  "id": 1459,
+                  "name": "symbol",
+                  "nodeType": "VariableDeclaration",
+                  "scope": 1467,
+                  "src": "36918:20:1",
+                  "stateVariable": false,
+                  "storageLocation": "memory",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_string_memory_ptr",
+                    "typeString": "string"
+                  },
+                  "typeName": {
+                    "id": 1458,
+                    "name": "string",
+                    "nodeType": "ElementaryTypeName",
+                    "src": "36918:6:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_string_storage_ptr",
+                      "typeString": "string"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                }
+              ],
+              "src": "36897:42:1"
+            },
+            "returnParameters": {
+              "id": 1465,
+              "nodeType": "ParameterList",
+              "parameters": [],
+              "src": "36976:0:1"
+            },
+            "scope": 1468,
+            "src": "36885:155:1",
+            "stateMutability": "nonpayable",
+            "superFunction": null,
+            "visibility": "public"
+          }
+        ],
+        "scope": 1469,
+        "src": "36815:227:1"
+      }
+    ],
+    "src": "61:36982:1"
+  },
+  "compiler": {
+    "name": "solc",
+    "version": "0.5.0+commit.1d4f565a.Emscripten.clang"
+  },
+  "networks": {},
+  "schemaVersion": "3.0.2",
+  "updatedAt": "2019-09-05T15:01:08.760Z",
+  "devdoc": {
+    "details": "Required interface of an ERC721 compliant contract.",
+    "methods": {
+      "balanceOf(address)": {
+        "details": "Returns the number of NFTs in `owner`'s account."
+      },
+      "ownerOf(uint256)": {
+        "details": "Returns the owner of the NFT specified by `tokenId`."
+      },
+      "safeTransferFrom(address,address,uint256)": {
+        "details": "Transfers a specific NFT (`tokenId`) from one account (`from`) to another (`to`).     *      * Requirements: - `from`, `to` cannot be zero. - `tokenId` must be owned by `from`. - If the caller is not `from`, it must be have been allowed to move this NFT by either `approve` or `setApproveForAll`."
+      },
+      "supportsInterface(bytes4)": {
+        "details": "Returns true if this contract implements the interface defined by `interfaceId`. See the corresponding [EIP section](https://eips.ethereum.org/EIPS/eip-165#how-interfaces-are-identified) to learn more about how these ids are created.     * This function call must use less than 30 000 gas."
+      },
+      "transferFrom(address,address,uint256)": {
+        "details": "Transfers a specific NFT (`tokenId`) from one account (`from`) to another (`to`).     * Requirements: - If the caller is not `from`, it must be approved to move this NFT by either `approve` or `setApproveForAll`."
+      }
+    }
+  },
+  "userdoc": {
+    "methods": {}
+  }
+}
\ No newline at end of file
diff --git a/src/abis/IERC721Enumerable.json b/src/abis/IERC721Enumerable.json
new file mode 100644
index 0000000..e5e0df8
--- /dev/null
+++ b/src/abis/IERC721Enumerable.json
@@ -0,0 +1,37793 @@
+{
+  "contractName": "IERC721Enumerable",
+  "abi": [
+    {
+      "constant": true,
+      "inputs": [
+        {
+          "name": "interfaceId",
+          "type": "bytes4"
+        }
+      ],
+      "name": "supportsInterface",
+      "outputs": [
+        {
+          "name": "",
+          "type": "bool"
+        }
+      ],
+      "payable": false,
+      "stateMutability": "view",
+      "type": "function"
+    },
+    {
+      "constant": true,
+      "inputs": [
+        {
+          "name": "tokenId",
+          "type": "uint256"
+        }
+      ],
+      "name": "getApproved",
+      "outputs": [
+        {
+          "name": "operator",
+          "type": "address"
+        }
+      ],
+      "payable": false,
+      "stateMutability": "view",
+      "type": "function"
+    },
+    {
+      "constant": false,
+      "inputs": [
+        {
+          "name": "to",
+          "type": "address"
+        },
+        {
+          "name": "tokenId",
+          "type": "uint256"
+        }
+      ],
+      "name": "approve",
+      "outputs": [],
+      "payable": false,
+      "stateMutability": "nonpayable",
+      "type": "function"
+    },
+    {
+      "constant": false,
+      "inputs": [
+        {
+          "name": "from",
+          "type": "address"
+        },
+        {
+          "name": "to",
+          "type": "address"
+        },
+        {
+          "name": "tokenId",
+          "type": "uint256"
+        }
+      ],
+      "name": "transferFrom",
+      "outputs": [],
+      "payable": false,
+      "stateMutability": "nonpayable",
+      "type": "function"
+    },
+    {
+      "constant": false,
+      "inputs": [
+        {
+          "name": "from",
+          "type": "address"
+        },
+        {
+          "name": "to",
+          "type": "address"
+        },
+        {
+          "name": "tokenId",
+          "type": "uint256"
+        }
+      ],
+      "name": "safeTransferFrom",
+      "outputs": [],
+      "payable": false,
+      "stateMutability": "nonpayable",
+      "type": "function"
+    },
+    {
+      "constant": true,
+      "inputs": [
+        {
+          "name": "tokenId",
+          "type": "uint256"
+        }
+      ],
+      "name": "ownerOf",
+      "outputs": [
+        {
+          "name": "owner",
+          "type": "address"
+        }
+      ],
+      "payable": false,
+      "stateMutability": "view",
+      "type": "function"
+    },
+    {
+      "constant": true,
+      "inputs": [
+        {
+          "name": "owner",
+          "type": "address"
+        }
+      ],
+      "name": "balanceOf",
+      "outputs": [
+        {
+          "name": "balance",
+          "type": "uint256"
+        }
+      ],
+      "payable": false,
+      "stateMutability": "view",
+      "type": "function"
+    },
+    {
+      "constant": false,
+      "inputs": [
+        {
+          "name": "operator",
+          "type": "address"
+        },
+        {
+          "name": "_approved",
+          "type": "bool"
+        }
+      ],
+      "name": "setApprovalForAll",
+      "outputs": [],
+      "payable": false,
+      "stateMutability": "nonpayable",
+      "type": "function"
+    },
+    {
+      "constant": false,
+      "inputs": [
+        {
+          "name": "from",
+          "type": "address"
+        },
+        {
+          "name": "to",
+          "type": "address"
+        },
+        {
+          "name": "tokenId",
+          "type": "uint256"
+        },
+        {
+          "name": "data",
+          "type": "bytes"
+        }
+      ],
+      "name": "safeTransferFrom",
+      "outputs": [],
+      "payable": false,
+      "stateMutability": "nonpayable",
+      "type": "function"
+    },
+    {
+      "constant": true,
+      "inputs": [
+        {
+          "name": "owner",
+          "type": "address"
+        },
+        {
+          "name": "operator",
+          "type": "address"
+        }
+      ],
+      "name": "isApprovedForAll",
+      "outputs": [
+        {
+          "name": "",
+          "type": "bool"
+        }
+      ],
+      "payable": false,
+      "stateMutability": "view",
+      "type": "function"
+    },
+    {
+      "anonymous": false,
+      "inputs": [
+        {
+          "indexed": true,
+          "name": "from",
+          "type": "address"
+        },
+        {
+          "indexed": true,
+          "name": "to",
+          "type": "address"
+        },
+        {
+          "indexed": true,
+          "name": "tokenId",
+          "type": "uint256"
+        }
+      ],
+      "name": "Transfer",
+      "type": "event"
+    },
+    {
+      "anonymous": false,
+      "inputs": [
+        {
+          "indexed": true,
+          "name": "owner",
+          "type": "address"
+        },
+        {
+          "indexed": true,
+          "name": "approved",
+          "type": "address"
+        },
+        {
+          "indexed": true,
+          "name": "tokenId",
+          "type": "uint256"
+        }
+      ],
+      "name": "Approval",
+      "type": "event"
+    },
+    {
+      "anonymous": false,
+      "inputs": [
+        {
+          "indexed": true,
+          "name": "owner",
+          "type": "address"
+        },
+        {
+          "indexed": true,
+          "name": "operator",
+          "type": "address"
+        },
+        {
+          "indexed": false,
+          "name": "approved",
+          "type": "bool"
+        }
+      ],
+      "name": "ApprovalForAll",
+      "type": "event"
+    },
+    {
+      "constant": true,
+      "inputs": [],
+      "name": "totalSupply",
+      "outputs": [
+        {
+          "name": "",
+          "type": "uint256"
+        }
+      ],
+      "payable": false,
+      "stateMutability": "view",
+      "type": "function"
+    },
+    {
+      "constant": true,
+      "inputs": [
+        {
+          "name": "owner",
+          "type": "address"
+        },
+        {
+          "name": "index",
+          "type": "uint256"
+        }
+      ],
+      "name": "tokenOfOwnerByIndex",
+      "outputs": [
+        {
+          "name": "tokenId",
+          "type": "uint256"
+        }
+      ],
+      "payable": false,
+      "stateMutability": "view",
+      "type": "function"
+    },
+    {
+      "constant": true,
+      "inputs": [
+        {
+          "name": "index",
+          "type": "uint256"
+        }
+      ],
+      "name": "tokenByIndex",
+      "outputs": [
+        {
+          "name": "",
+          "type": "uint256"
+        }
+      ],
+      "payable": false,
+      "stateMutability": "view",
+      "type": "function"
+    }
+  ],
+  "bytecode": "0x",
+  "deployedBytecode": "0x",
+  "sourceMap": "",
+  "deployedSourceMap": "",
+  "source": "\n// File: @openzeppelin/contracts/introspection/IERC165.sol\n\npragma solidity ^0.5.0;\n\n/**\n * @dev Interface of the ERC165 standard, as defined in the\n * [EIP](https://eips.ethereum.org/EIPS/eip-165).\n *\n * Implementers can declare support of contract interfaces, which can then be\n * queried by others (`ERC165Checker`).\n *\n * For an implementation, see `ERC165`.\n */\ninterface IERC165 {\n    /**\n     * @dev Returns true if this contract implements the interface defined by\n     * `interfaceId`. See the corresponding\n     * [EIP section](https://eips.ethereum.org/EIPS/eip-165#how-interfaces-are-identified)\n     * to learn more about how these ids are created.\n     *\n     * This function call must use less than 30 000 gas.\n     */\n    function supportsInterface(bytes4 interfaceId) external view returns (bool);\n}\n\n// File: @openzeppelin/contracts/token/ERC721/IERC721.sol\n\npragma solidity ^0.5.0;\n\n\n/**\n * @dev Required interface of an ERC721 compliant contract.\n */\ncontract IERC721 is IERC165 {\n    event Transfer(address indexed from, address indexed to, uint256 indexed tokenId);\n    event Approval(address indexed owner, address indexed approved, uint256 indexed tokenId);\n    event ApprovalForAll(address indexed owner, address indexed operator, bool approved);\n\n    /**\n     * @dev Returns the number of NFTs in `owner`'s account.\n     */\n    function balanceOf(address owner) public view returns (uint256 balance);\n\n    /**\n     * @dev Returns the owner of the NFT specified by `tokenId`.\n     */\n    function ownerOf(uint256 tokenId) public view returns (address owner);\n\n    /**\n     * @dev Transfers a specific NFT (`tokenId`) from one account (`from`) to\n     * another (`to`).\n     *\n     * \n     *\n     * Requirements:\n     * - `from`, `to` cannot be zero.\n     * - `tokenId` must be owned by `from`.\n     * - If the caller is not `from`, it must be have been allowed to move this\n     * NFT by either `approve` or `setApproveForAll`.\n     */\n    function safeTransferFrom(address from, address to, uint256 tokenId) public;\n    /**\n     * @dev Transfers a specific NFT (`tokenId`) from one account (`from`) to\n     * another (`to`).\n     *\n     * Requirements:\n     * - If the caller is not `from`, it must be approved to move this NFT by\n     * either `approve` or `setApproveForAll`.\n     */\n    function transferFrom(address from, address to, uint256 tokenId) public;\n    function approve(address to, uint256 tokenId) public;\n    function getApproved(uint256 tokenId) public view returns (address operator);\n\n    function setApprovalForAll(address operator, bool _approved) public;\n    function isApprovedForAll(address owner, address operator) public view returns (bool);\n\n\n    function safeTransferFrom(address from, address to, uint256 tokenId, bytes memory data) public;\n}\n\n// File: @openzeppelin/contracts/token/ERC721/IERC721Receiver.sol\n\npragma solidity ^0.5.0;\n\n/**\n * @title ERC721 token receiver interface\n * @dev Interface for any contract that wants to support safeTransfers\n * from ERC721 asset contracts.\n */\ncontract IERC721Receiver {\n    /**\n     * @notice Handle the receipt of an NFT\n     * @dev The ERC721 smart contract calls this function on the recipient\n     * after a `safeTransfer`. This function MUST return the function selector,\n     * otherwise the caller will revert the transaction. The selector to be\n     * returned can be obtained as `this.onERC721Received.selector`. This\n     * function MAY throw to revert and reject the transfer.\n     * Note: the ERC721 contract address is always the message sender.\n     * @param operator The address which called `safeTransferFrom` function\n     * @param from The address which previously owned the token\n     * @param tokenId The NFT identifier which is being transferred\n     * @param data Additional data with no specified format\n     * @return bytes4 `bytes4(keccak256(\"onERC721Received(address,address,uint256,bytes)\"))`\n     */\n    function onERC721Received(address operator, address from, uint256 tokenId, bytes memory data)\n    public returns (bytes4);\n}\n\n// File: @openzeppelin/contracts/math/SafeMath.sol\n\npragma solidity ^0.5.0;\n\n/**\n * @dev Wrappers over Solidity's arithmetic operations with added overflow\n * checks.\n *\n * Arithmetic operations in Solidity wrap on overflow. This can easily result\n * in bugs, because programmers usually assume that an overflow raises an\n * error, which is the standard behavior in high level programming languages.\n * `SafeMath` restores this intuition by reverting the transaction when an\n * operation overflows.\n *\n * Using this library instead of the unchecked operations eliminates an entire\n * class of bugs, so it's recommended to use it always.\n */\nlibrary SafeMath {\n    /**\n     * @dev Returns the addition of two unsigned integers, reverting on\n     * overflow.\n     *\n     * Counterpart to Solidity's `+` operator.\n     *\n     * Requirements:\n     * - Addition cannot overflow.\n     */\n    function add(uint256 a, uint256 b) internal pure returns (uint256) {\n        uint256 c = a + b;\n        require(c >= a, \"SafeMath: addition overflow\");\n\n        return c;\n    }\n\n    /**\n     * @dev Returns the subtraction of two unsigned integers, reverting on\n     * overflow (when the result is negative).\n     *\n     * Counterpart to Solidity's `-` operator.\n     *\n     * Requirements:\n     * - Subtraction cannot overflow.\n     */\n    function sub(uint256 a, uint256 b) internal pure returns (uint256) {\n        require(b <= a, \"SafeMath: subtraction overflow\");\n        uint256 c = a - b;\n\n        return c;\n    }\n\n    /**\n     * @dev Returns the multiplication of two unsigned integers, reverting on\n     * overflow.\n     *\n     * Counterpart to Solidity's `*` operator.\n     *\n     * Requirements:\n     * - Multiplication cannot overflow.\n     */\n    function mul(uint256 a, uint256 b) internal pure returns (uint256) {\n        // Gas optimization: this is cheaper than requiring 'a' not being zero, but the\n        // benefit is lost if 'b' is also tested.\n        // See: https://github.com/OpenZeppelin/openzeppelin-contracts/pull/522\n        if (a == 0) {\n            return 0;\n        }\n\n        uint256 c = a * b;\n        require(c / a == b, \"SafeMath: multiplication overflow\");\n\n        return c;\n    }\n\n    /**\n     * @dev Returns the integer division of two unsigned integers. Reverts on\n     * division by zero. The result is rounded towards zero.\n     *\n     * Counterpart to Solidity's `/` operator. Note: this function uses a\n     * `revert` opcode (which leaves remaining gas untouched) while Solidity\n     * uses an invalid opcode to revert (consuming all remaining gas).\n     *\n     * Requirements:\n     * - The divisor cannot be zero.\n     */\n    function div(uint256 a, uint256 b) internal pure returns (uint256) {\n        // Solidity only automatically asserts when dividing by 0\n        require(b > 0, \"SafeMath: division by zero\");\n        uint256 c = a / b;\n        // assert(a == b * c + a % b); // There is no case in which this doesn't hold\n\n        return c;\n    }\n\n    /**\n     * @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo),\n     * Reverts when dividing by zero.\n     *\n     * Counterpart to Solidity's `%` operator. This function uses a `revert`\n     * opcode (which leaves remaining gas untouched) while Solidity uses an\n     * invalid opcode to revert (consuming all remaining gas).\n     *\n     * Requirements:\n     * - The divisor cannot be zero.\n     */\n    function mod(uint256 a, uint256 b) internal pure returns (uint256) {\n        require(b != 0, \"SafeMath: modulo by zero\");\n        return a % b;\n    }\n}\n\n// File: @openzeppelin/contracts/utils/Address.sol\n\npragma solidity ^0.5.0;\n\n/**\n * @dev Collection of functions related to the address type,\n */\nlibrary Address {\n    /**\n     * @dev Returns true if `account` is a contract.\n     *\n     * This test is non-exhaustive, and there may be false-negatives: during the\n     * execution of a contract's constructor, its address will be reported as\n     * not containing a contract.\n     *\n     * > It is unsafe to assume that an address for which this function returns\n     * false is an externally-owned account (EOA) and not a contract.\n     */\n    function isContract(address account) internal view returns (bool) {\n        // This method relies in extcodesize, which returns 0 for contracts in\n        // construction, since the code is only stored at the end of the\n        // constructor execution.\n\n        uint256 size;\n        // solhint-disable-next-line no-inline-assembly\n        assembly { size := extcodesize(account) }\n        return size > 0;\n    }\n}\n\n// File: @openzeppelin/contracts/drafts/Counters.sol\n\npragma solidity ^0.5.0;\n\n\n/**\n * @title Counters\n * @author Matt Condon (@shrugs)\n * @dev Provides counters that can only be incremented or decremented by one. This can be used e.g. to track the number\n * of elements in a mapping, issuing ERC721 ids, or counting request ids.\n *\n * Include with `using Counters for Counters.Counter;`\n * Since it is not possible to overflow a 256 bit integer with increments of one, `increment` can skip the SafeMath\n * overflow check, thereby saving gas. This does assume however correct usage, in that the underlying `_value` is never\n * directly accessed.\n */\nlibrary Counters {\n    using SafeMath for uint256;\n\n    struct Counter {\n        // This variable should never be directly accessed by users of the library: interactions must be restricted to\n        // the library's function. As of Solidity v0.5.2, this cannot be enforced, though there is a proposal to add\n        // this feature: see https://github.com/ethereum/solidity/issues/4637\n        uint256 _value; // default: 0\n    }\n\n    function current(Counter storage counter) internal view returns (uint256) {\n        return counter._value;\n    }\n\n    function increment(Counter storage counter) internal {\n        counter._value += 1;\n    }\n\n    function decrement(Counter storage counter) internal {\n        counter._value = counter._value.sub(1);\n    }\n}\n\n// File: @openzeppelin/contracts/introspection/ERC165.sol\n\npragma solidity ^0.5.0;\n\n\n/**\n * @dev Implementation of the `IERC165` interface.\n *\n * Contracts may inherit from this and call `_registerInterface` to declare\n * their support of an interface.\n */\ncontract ERC165 is IERC165 {\n    /*\n     * bytes4(keccak256('supportsInterface(bytes4)')) == 0x01ffc9a7\n     */\n    bytes4 private constant _INTERFACE_ID_ERC165 = 0x01ffc9a7;\n\n    /**\n     * @dev Mapping of interface ids to whether or not it's supported.\n     */\n    mapping(bytes4 => bool) private _supportedInterfaces;\n\n    constructor () internal {\n        // Derived contracts need only register support for their own interfaces,\n        // we register support for ERC165 itself here\n        _registerInterface(_INTERFACE_ID_ERC165);\n    }\n\n    /**\n     * @dev See `IERC165.supportsInterface`.\n     *\n     * Time complexity O(1), guaranteed to always use less than 30 000 gas.\n     */\n    function supportsInterface(bytes4 interfaceId) external view returns (bool) {\n        return _supportedInterfaces[interfaceId];\n    }\n\n    /**\n     * @dev Registers the contract as an implementer of the interface defined by\n     * `interfaceId`. Support of the actual ERC165 interface is automatic and\n     * registering its interface id is not required.\n     *\n     * See `IERC165.supportsInterface`.\n     *\n     * Requirements:\n     *\n     * - `interfaceId` cannot be the ERC165 invalid interface (`0xffffffff`).\n     */\n    function _registerInterface(bytes4 interfaceId) internal {\n        require(interfaceId != 0xffffffff, \"ERC165: invalid interface id\");\n        _supportedInterfaces[interfaceId] = true;\n    }\n}\n\n// File: @openzeppelin/contracts/token/ERC721/ERC721.sol\n\npragma solidity ^0.5.0;\n\n\n\n\n\n\n\n/**\n * @title ERC721 Non-Fungible Token Standard basic implementation\n * @dev see https://eips.ethereum.org/EIPS/eip-721\n */\ncontract ERC721 is ERC165, IERC721 {\n    using SafeMath for uint256;\n    using Address for address;\n    using Counters for Counters.Counter;\n\n    // Equals to `bytes4(keccak256(\"onERC721Received(address,address,uint256,bytes)\"))`\n    // which can be also obtained as `IERC721Receiver(0).onERC721Received.selector`\n    bytes4 private constant _ERC721_RECEIVED = 0x150b7a02;\n\n    // Mapping from token ID to owner\n    mapping (uint256 => address) private _tokenOwner;\n\n    // Mapping from token ID to approved address\n    mapping (uint256 => address) private _tokenApprovals;\n\n    // Mapping from owner to number of owned token\n    mapping (address => Counters.Counter) private _ownedTokensCount;\n\n    // Mapping from owner to operator approvals\n    mapping (address => mapping (address => bool)) private _operatorApprovals;\n\n    /*\n     *     bytes4(keccak256('balanceOf(address)')) == 0x70a08231\n     *     bytes4(keccak256('ownerOf(uint256)')) == 0x6352211e\n     *     bytes4(keccak256('approve(address,uint256)')) == 0x095ea7b3\n     *     bytes4(keccak256('getApproved(uint256)')) == 0x081812fc\n     *     bytes4(keccak256('setApprovalForAll(address,bool)')) == 0xa22cb465\n     *     bytes4(keccak256('isApprovedForAll(address,address)')) == 0xe985e9c\n     *     bytes4(keccak256('transferFrom(address,address,uint256)')) == 0x23b872dd\n     *     bytes4(keccak256('safeTransferFrom(address,address,uint256)')) == 0x42842e0e\n     *     bytes4(keccak256('safeTransferFrom(address,address,uint256,bytes)')) == 0xb88d4fde\n     *\n     *     => 0x70a08231 ^ 0x6352211e ^ 0x095ea7b3 ^ 0x081812fc ^\n     *        0xa22cb465 ^ 0xe985e9c ^ 0x23b872dd ^ 0x42842e0e ^ 0xb88d4fde == 0x80ac58cd\n     */\n    bytes4 private constant _INTERFACE_ID_ERC721 = 0x80ac58cd;\n\n    constructor () public {\n        // register the supported interfaces to conform to ERC721 via ERC165\n        _registerInterface(_INTERFACE_ID_ERC721);\n    }\n\n    /**\n     * @dev Gets the balance of the specified address.\n     * @param owner address to query the balance of\n     * @return uint256 representing the amount owned by the passed address\n     */\n    function balanceOf(address owner) public view returns (uint256) {\n        require(owner != address(0), \"ERC721: balance query for the zero address\");\n\n        return _ownedTokensCount[owner].current();\n    }\n\n    /**\n     * @dev Gets the owner of the specified token ID.\n     * @param tokenId uint256 ID of the token to query the owner of\n     * @return address currently marked as the owner of the given token ID\n     */\n    function ownerOf(uint256 tokenId) public view returns (address) {\n        address owner = _tokenOwner[tokenId];\n        require(owner != address(0), \"ERC721: owner query for nonexistent token\");\n\n        return owner;\n    }\n\n    /**\n     * @dev Approves another address to transfer the given token ID\n     * The zero address indicates there is no approved address.\n     * There can only be one approved address per token at a given time.\n     * Can only be called by the token owner or an approved operator.\n     * @param to address to be approved for the given token ID\n     * @param tokenId uint256 ID of the token to be approved\n     */\n    function approve(address to, uint256 tokenId) public {\n        address owner = ownerOf(tokenId);\n        require(to != owner, \"ERC721: approval to current owner\");\n\n        require(msg.sender == owner || isApprovedForAll(owner, msg.sender),\n            \"ERC721: approve caller is not owner nor approved for all\"\n        );\n\n        _tokenApprovals[tokenId] = to;\n        emit Approval(owner, to, tokenId);\n    }\n\n    /**\n     * @dev Gets the approved address for a token ID, or zero if no address set\n     * Reverts if the token ID does not exist.\n     * @param tokenId uint256 ID of the token to query the approval of\n     * @return address currently approved for the given token ID\n     */\n    function getApproved(uint256 tokenId) public view returns (address) {\n        require(_exists(tokenId), \"ERC721: approved query for nonexistent token\");\n\n        return _tokenApprovals[tokenId];\n    }\n\n    /**\n     * @dev Sets or unsets the approval of a given operator\n     * An operator is allowed to transfer all tokens of the sender on their behalf.\n     * @param to operator address to set the approval\n     * @param approved representing the status of the approval to be set\n     */\n    function setApprovalForAll(address to, bool approved) public {\n        require(to != msg.sender, \"ERC721: approve to caller\");\n\n        _operatorApprovals[msg.sender][to] = approved;\n        emit ApprovalForAll(msg.sender, to, approved);\n    }\n\n    /**\n     * @dev Tells whether an operator is approved by a given owner.\n     * @param owner owner address which you want to query the approval of\n     * @param operator operator address which you want to query the approval of\n     * @return bool whether the given operator is approved by the given owner\n     */\n    function isApprovedForAll(address owner, address operator) public view returns (bool) {\n        return _operatorApprovals[owner][operator];\n    }\n\n    /**\n     * @dev Transfers the ownership of a given token ID to another address.\n     * Usage of this method is discouraged, use `safeTransferFrom` whenever possible.\n     * Requires the msg.sender to be the owner, approved, or operator.\n     * @param from current owner of the token\n     * @param to address to receive the ownership of the given token ID\n     * @param tokenId uint256 ID of the token to be transferred\n     */\n    function transferFrom(address from, address to, uint256 tokenId) public {\n        //solhint-disable-next-line max-line-length\n        require(_isApprovedOrOwner(msg.sender, tokenId), \"ERC721: transfer caller is not owner nor approved\");\n\n        _transferFrom(from, to, tokenId);\n    }\n\n    /**\n     * @dev Safely transfers the ownership of a given token ID to another address\n     * If the target address is a contract, it must implement `onERC721Received`,\n     * which is called upon a safe transfer, and return the magic value\n     * `bytes4(keccak256(\"onERC721Received(address,address,uint256,bytes)\"))`; otherwise,\n     * the transfer is reverted.\n     * Requires the msg.sender to be the owner, approved, or operator\n     * @param from current owner of the token\n     * @param to address to receive the ownership of the given token ID\n     * @param tokenId uint256 ID of the token to be transferred\n     */\n    function safeTransferFrom(address from, address to, uint256 tokenId) public {\n        safeTransferFrom(from, to, tokenId, \"\");\n    }\n\n    /**\n     * @dev Safely transfers the ownership of a given token ID to another address\n     * If the target address is a contract, it must implement `onERC721Received`,\n     * which is called upon a safe transfer, and return the magic value\n     * `bytes4(keccak256(\"onERC721Received(address,address,uint256,bytes)\"))`; otherwise,\n     * the transfer is reverted.\n     * Requires the msg.sender to be the owner, approved, or operator\n     * @param from current owner of the token\n     * @param to address to receive the ownership of the given token ID\n     * @param tokenId uint256 ID of the token to be transferred\n     * @param _data bytes data to send along with a safe transfer check\n     */\n    function safeTransferFrom(address from, address to, uint256 tokenId, bytes memory _data) public {\n        transferFrom(from, to, tokenId);\n        require(_checkOnERC721Received(from, to, tokenId, _data), \"ERC721: transfer to non ERC721Receiver implementer\");\n    }\n\n    /**\n     * @dev Returns whether the specified token exists.\n     * @param tokenId uint256 ID of the token to query the existence of\n     * @return bool whether the token exists\n     */\n    function _exists(uint256 tokenId) internal view returns (bool) {\n        address owner = _tokenOwner[tokenId];\n        return owner != address(0);\n    }\n\n    /**\n     * @dev Returns whether the given spender can transfer a given token ID.\n     * @param spender address of the spender to query\n     * @param tokenId uint256 ID of the token to be transferred\n     * @return bool whether the msg.sender is approved for the given token ID,\n     * is an operator of the owner, or is the owner of the token\n     */\n    function _isApprovedOrOwner(address spender, uint256 tokenId) internal view returns (bool) {\n        require(_exists(tokenId), \"ERC721: operator query for nonexistent token\");\n        address owner = ownerOf(tokenId);\n        return (spender == owner || getApproved(tokenId) == spender || isApprovedForAll(owner, spender));\n    }\n\n    /**\n     * @dev Internal function to mint a new token.\n     * Reverts if the given token ID already exists.\n     * @param to The address that will own the minted token\n     * @param tokenId uint256 ID of the token to be minted\n     */\n    function _mint(address to, uint256 tokenId) internal {\n        require(to != address(0), \"ERC721: mint to the zero address\");\n        require(!_exists(tokenId), \"ERC721: token already minted\");\n\n        _tokenOwner[tokenId] = to;\n        _ownedTokensCount[to].increment();\n\n        emit Transfer(address(0), to, tokenId);\n    }\n\n    /**\n     * @dev Internal function to burn a specific token.\n     * Reverts if the token does not exist.\n     * Deprecated, use _burn(uint256) instead.\n     * @param owner owner of the token to burn\n     * @param tokenId uint256 ID of the token being burned\n     */\n    function _burn(address owner, uint256 tokenId) internal {\n        require(ownerOf(tokenId) == owner, \"ERC721: burn of token that is not own\");\n\n        _clearApproval(tokenId);\n\n        _ownedTokensCount[owner].decrement();\n        _tokenOwner[tokenId] = address(0);\n\n        emit Transfer(owner, address(0), tokenId);\n    }\n\n    /**\n     * @dev Internal function to burn a specific token.\n     * Reverts if the token does not exist.\n     * @param tokenId uint256 ID of the token being burned\n     */\n    function _burn(uint256 tokenId) internal {\n        _burn(ownerOf(tokenId), tokenId);\n    }\n\n    /**\n     * @dev Internal function to transfer ownership of a given token ID to another address.\n     * As opposed to transferFrom, this imposes no restrictions on msg.sender.\n     * @param from current owner of the token\n     * @param to address to receive the ownership of the given token ID\n     * @param tokenId uint256 ID of the token to be transferred\n     */\n    function _transferFrom(address from, address to, uint256 tokenId) internal {\n        require(ownerOf(tokenId) == from, \"ERC721: transfer of token that is not own\");\n        require(to != address(0), \"ERC721: transfer to the zero address\");\n\n        _clearApproval(tokenId);\n\n        _ownedTokensCount[from].decrement();\n        _ownedTokensCount[to].increment();\n\n        _tokenOwner[tokenId] = to;\n\n        emit Transfer(from, to, tokenId);\n    }\n\n    /**\n     * @dev Internal function to invoke `onERC721Received` on a target address.\n     * The call is not executed if the target address is not a contract.\n     *\n     * This function is deprecated.\n     * @param from address representing the previous owner of the given token ID\n     * @param to target address that will receive the tokens\n     * @param tokenId uint256 ID of the token to be transferred\n     * @param _data bytes optional data to send along with the call\n     * @return bool whether the call correctly returned the expected magic value\n     */\n    function _checkOnERC721Received(address from, address to, uint256 tokenId, bytes memory _data)\n        internal returns (bool)\n    {\n        if (!to.isContract()) {\n            return true;\n        }\n\n        bytes4 retval = IERC721Receiver(to).onERC721Received(msg.sender, from, tokenId, _data);\n        return (retval == _ERC721_RECEIVED);\n    }\n\n    /**\n     * @dev Private function to clear current approval of a given token ID.\n     * @param tokenId uint256 ID of the token to be transferred\n     */\n    function _clearApproval(uint256 tokenId) private {\n        if (_tokenApprovals[tokenId] != address(0)) {\n            _tokenApprovals[tokenId] = address(0);\n        }\n    }\n}\n\n// File: @openzeppelin/contracts/token/ERC721/IERC721Enumerable.sol\n\npragma solidity ^0.5.0;\n\n\n/**\n * @title ERC-721 Non-Fungible Token Standard, optional enumeration extension\n * @dev See https://eips.ethereum.org/EIPS/eip-721\n */\ncontract IERC721Enumerable is IERC721 {\n    function totalSupply() public view returns (uint256);\n    function tokenOfOwnerByIndex(address owner, uint256 index) public view returns (uint256 tokenId);\n\n    function tokenByIndex(uint256 index) public view returns (uint256);\n}\n\n// File: @openzeppelin/contracts/token/ERC721/ERC721Enumerable.sol\n\npragma solidity ^0.5.0;\n\n\n\n\n/**\n * @title ERC-721 Non-Fungible Token with optional enumeration extension logic\n * @dev See https://eips.ethereum.org/EIPS/eip-721\n */\ncontract ERC721Enumerable is ERC165, ERC721, IERC721Enumerable {\n    // Mapping from owner to list of owned token IDs\n    mapping(address => uint256[]) private _ownedTokens;\n\n    // Mapping from token ID to index of the owner tokens list\n    mapping(uint256 => uint256) private _ownedTokensIndex;\n\n    // Array with all token ids, used for enumeration\n    uint256[] private _allTokens;\n\n    // Mapping from token id to position in the allTokens array\n    mapping(uint256 => uint256) private _allTokensIndex;\n\n    /*\n     *     bytes4(keccak256('totalSupply()')) == 0x18160ddd\n     *     bytes4(keccak256('tokenOfOwnerByIndex(address,uint256)')) == 0x2f745c59\n     *     bytes4(keccak256('tokenByIndex(uint256)')) == 0x4f6ccce7\n     *\n     *     => 0x18160ddd ^ 0x2f745c59 ^ 0x4f6ccce7 == 0x780e9d63\n     */\n    bytes4 private constant _INTERFACE_ID_ERC721_ENUMERABLE = 0x780e9d63;\n\n    /**\n     * @dev Constructor function.\n     */\n    constructor () public {\n        // register the supported interface to conform to ERC721Enumerable via ERC165\n        _registerInterface(_INTERFACE_ID_ERC721_ENUMERABLE);\n    }\n\n    /**\n     * @dev Gets the token ID at a given index of the tokens list of the requested owner.\n     * @param owner address owning the tokens list to be accessed\n     * @param index uint256 representing the index to be accessed of the requested tokens list\n     * @return uint256 token ID at the given index of the tokens list owned by the requested address\n     */\n    function tokenOfOwnerByIndex(address owner, uint256 index) public view returns (uint256) {\n        require(index < balanceOf(owner), \"ERC721Enumerable: owner index out of bounds\");\n        return _ownedTokens[owner][index];\n    }\n\n    /**\n     * @dev Gets the total amount of tokens stored by the contract.\n     * @return uint256 representing the total amount of tokens\n     */\n    function totalSupply() public view returns (uint256) {\n        return _allTokens.length;\n    }\n\n    /**\n     * @dev Gets the token ID at a given index of all the tokens in this contract\n     * Reverts if the index is greater or equal to the total number of tokens.\n     * @param index uint256 representing the index to be accessed of the tokens list\n     * @return uint256 token ID at the given index of the tokens list\n     */\n    function tokenByIndex(uint256 index) public view returns (uint256) {\n        require(index < totalSupply(), \"ERC721Enumerable: global index out of bounds\");\n        return _allTokens[index];\n    }\n\n    /**\n     * @dev Internal function to transfer ownership of a given token ID to another address.\n     * As opposed to transferFrom, this imposes no restrictions on msg.sender.\n     * @param from current owner of the token\n     * @param to address to receive the ownership of the given token ID\n     * @param tokenId uint256 ID of the token to be transferred\n     */\n    function _transferFrom(address from, address to, uint256 tokenId) internal {\n        super._transferFrom(from, to, tokenId);\n\n        _removeTokenFromOwnerEnumeration(from, tokenId);\n\n        _addTokenToOwnerEnumeration(to, tokenId);\n    }\n\n    /**\n     * @dev Internal function to mint a new token.\n     * Reverts if the given token ID already exists.\n     * @param to address the beneficiary that will own the minted token\n     * @param tokenId uint256 ID of the token to be minted\n     */\n    function _mint(address to, uint256 tokenId) internal {\n        super._mint(to, tokenId);\n\n        _addTokenToOwnerEnumeration(to, tokenId);\n\n        _addTokenToAllTokensEnumeration(tokenId);\n    }\n\n    /**\n     * @dev Internal function to burn a specific token.\n     * Reverts if the token does not exist.\n     * Deprecated, use _burn(uint256) instead.\n     * @param owner owner of the token to burn\n     * @param tokenId uint256 ID of the token being burned\n     */\n    function _burn(address owner, uint256 tokenId) internal {\n        super._burn(owner, tokenId);\n\n        _removeTokenFromOwnerEnumeration(owner, tokenId);\n        // Since tokenId will be deleted, we can clear its slot in _ownedTokensIndex to trigger a gas refund\n        _ownedTokensIndex[tokenId] = 0;\n\n        _removeTokenFromAllTokensEnumeration(tokenId);\n    }\n\n    /**\n     * @dev Gets the list of token IDs of the requested owner.\n     * @param owner address owning the tokens\n     * @return uint256[] List of token IDs owned by the requested address\n     */\n    function _tokensOfOwner(address owner) internal view returns (uint256[] storage) {\n        return _ownedTokens[owner];\n    }\n\n    /**\n     * @dev Private function to add a token to this extension's ownership-tracking data structures.\n     * @param to address representing the new owner of the given token ID\n     * @param tokenId uint256 ID of the token to be added to the tokens list of the given address\n     */\n    function _addTokenToOwnerEnumeration(address to, uint256 tokenId) private {\n        _ownedTokensIndex[tokenId] = _ownedTokens[to].length;\n        _ownedTokens[to].push(tokenId);\n    }\n\n    /**\n     * @dev Private function to add a token to this extension's token tracking data structures.\n     * @param tokenId uint256 ID of the token to be added to the tokens list\n     */\n    function _addTokenToAllTokensEnumeration(uint256 tokenId) private {\n        _allTokensIndex[tokenId] = _allTokens.length;\n        _allTokens.push(tokenId);\n    }\n\n    /**\n     * @dev Private function to remove a token from this extension's ownership-tracking data structures. Note that\n     * while the token is not assigned a new owner, the _ownedTokensIndex mapping is _not_ updated: this allows for\n     * gas optimizations e.g. when performing a transfer operation (avoiding double writes).\n     * This has O(1) time complexity, but alters the order of the _ownedTokens array.\n     * @param from address representing the previous owner of the given token ID\n     * @param tokenId uint256 ID of the token to be removed from the tokens list of the given address\n     */\n    function _removeTokenFromOwnerEnumeration(address from, uint256 tokenId) private {\n        // To prevent a gap in from's tokens array, we store the last token in the index of the token to delete, and\n        // then delete the last slot (swap and pop).\n\n        uint256 lastTokenIndex = _ownedTokens[from].length.sub(1);\n        uint256 tokenIndex = _ownedTokensIndex[tokenId];\n\n        // When the token to delete is the last token, the swap operation is unnecessary\n        if (tokenIndex != lastTokenIndex) {\n            uint256 lastTokenId = _ownedTokens[from][lastTokenIndex];\n\n            _ownedTokens[from][tokenIndex] = lastTokenId; // Move the last token to the slot of the to-delete token\n            _ownedTokensIndex[lastTokenId] = tokenIndex; // Update the moved token's index\n        }\n\n        // This also deletes the contents at the last position of the array\n        _ownedTokens[from].length--;\n\n        // Note that _ownedTokensIndex[tokenId] hasn't been cleared: it still points to the old slot (now occupied by\n        // lastTokenId, or just over the end of the array if the token was the last one).\n    }\n\n    /**\n     * @dev Private function to remove a token from this extension's token tracking data structures.\n     * This has O(1) time complexity, but alters the order of the _allTokens array.\n     * @param tokenId uint256 ID of the token to be removed from the tokens list\n     */\n    function _removeTokenFromAllTokensEnumeration(uint256 tokenId) private {\n        // To prevent a gap in the tokens array, we store the last token in the index of the token to delete, and\n        // then delete the last slot (swap and pop).\n\n        uint256 lastTokenIndex = _allTokens.length.sub(1);\n        uint256 tokenIndex = _allTokensIndex[tokenId];\n\n        // When the token to delete is the last token, the swap operation is unnecessary. However, since this occurs so\n        // rarely (when the last minted token is burnt) that we still do the swap here to avoid the gas cost of adding\n        // an 'if' statement (like in _removeTokenFromOwnerEnumeration)\n        uint256 lastTokenId = _allTokens[lastTokenIndex];\n\n        _allTokens[tokenIndex] = lastTokenId; // Move the last token to the slot of the to-delete token\n        _allTokensIndex[lastTokenId] = tokenIndex; // Update the moved token's index\n\n        // This also deletes the contents at the last position of the array\n        _allTokens.length--;\n        _allTokensIndex[tokenId] = 0;\n    }\n}\n\n// File: @openzeppelin/contracts/token/ERC721/IERC721Metadata.sol\n\npragma solidity ^0.5.0;\n\n\n/**\n * @title ERC-721 Non-Fungible Token Standard, optional metadata extension\n * @dev See https://eips.ethereum.org/EIPS/eip-721\n */\ncontract IERC721Metadata is IERC721 {\n    function name() external view returns (string memory);\n    function symbol() external view returns (string memory);\n    function tokenURI(uint256 tokenId) external view returns (string memory);\n}\n\n// File: @openzeppelin/contracts/token/ERC721/ERC721Metadata.sol\n\npragma solidity ^0.5.0;\n\n\n\n\ncontract ERC721Metadata is ERC165, ERC721, IERC721Metadata {\n    // Token name\n    string private _name;\n\n    // Token symbol\n    string private _symbol;\n\n    // Optional mapping for token URIs\n    mapping(uint256 => string) private _tokenURIs;\n\n    /*\n     *     bytes4(keccak256('name()')) == 0x06fdde03\n     *     bytes4(keccak256('symbol()')) == 0x95d89b41\n     *     bytes4(keccak256('tokenURI(uint256)')) == 0xc87b56dd\n     *\n     *     => 0x06fdde03 ^ 0x95d89b41 ^ 0xc87b56dd == 0x5b5e139f\n     */\n    bytes4 private constant _INTERFACE_ID_ERC721_METADATA = 0x5b5e139f;\n\n    /**\n     * @dev Constructor function\n     */\n    constructor (string memory name, string memory symbol) public {\n        _name = name;\n        _symbol = symbol;\n\n        // register the supported interfaces to conform to ERC721 via ERC165\n        _registerInterface(_INTERFACE_ID_ERC721_METADATA);\n    }\n\n    /**\n     * @dev Gets the token name.\n     * @return string representing the token name\n     */\n    function name() external view returns (string memory) {\n        return _name;\n    }\n\n    /**\n     * @dev Gets the token symbol.\n     * @return string representing the token symbol\n     */\n    function symbol() external view returns (string memory) {\n        return _symbol;\n    }\n\n    /**\n     * @dev Returns an URI for a given token ID.\n     * Throws if the token ID does not exist. May return an empty string.\n     * @param tokenId uint256 ID of the token to query\n     */\n    function tokenURI(uint256 tokenId) external view returns (string memory) {\n        require(_exists(tokenId), \"ERC721Metadata: URI query for nonexistent token\");\n        return _tokenURIs[tokenId];\n    }\n\n    /**\n     * @dev Internal function to set the token URI for a given token.\n     * Reverts if the token ID does not exist.\n     * @param tokenId uint256 ID of the token to set its URI\n     * @param uri string URI to assign\n     */\n    function _setTokenURI(uint256 tokenId, string memory uri) internal {\n        require(_exists(tokenId), \"ERC721Metadata: URI set of nonexistent token\");\n        _tokenURIs[tokenId] = uri;\n    }\n\n    /**\n     * @dev Internal function to burn a specific token.\n     * Reverts if the token does not exist.\n     * Deprecated, use _burn(uint256) instead.\n     * @param owner owner of the token to burn\n     * @param tokenId uint256 ID of the token being burned by the msg.sender\n     */\n    function _burn(address owner, uint256 tokenId) internal {\n        super._burn(owner, tokenId);\n\n        // Clear metadata (if any)\n        if (bytes(_tokenURIs[tokenId]).length != 0) {\n            delete _tokenURIs[tokenId];\n        }\n    }\n}\n\n// File: @openzeppelin/contracts/token/ERC721/ERC721Full.sol\n\npragma solidity ^0.5.0;\n\n\n\n\n/**\n * @title Full ERC721 Token\n * This implementation includes all the required and some optional functionality of the ERC721 standard\n * Moreover, it includes approve all functionality using operator terminology\n * @dev see https://eips.ethereum.org/EIPS/eip-721\n */\ncontract ERC721Full is ERC721, ERC721Enumerable, ERC721Metadata {\n    constructor (string memory name, string memory symbol) public ERC721Metadata(name, symbol) {\n        // solhint-disable-previous-line no-empty-blocks\n    }\n}\n",
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+                          "typeIdentifier": "t_mapping$_t_uint256_$_t_address_$",
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+                          "typeString": "uint256"
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+                        "typeString": "address"
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+                        "name": "from",
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+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        }
+                      },
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+                        "name": "to",
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+                        "typeDescriptions": {
+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        }
+                      },
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+                        "src": "22780:7:1",
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+                          "typeString": "uint256"
+                        }
+                      }
+                    ],
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+                      "argumentTypes": [
+                        {
+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        },
+                        {
+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        },
+                        {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      ],
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+                      "name": "Transfer",
+                      "nodeType": "Identifier",
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+                      }
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+                  "nodeType": "EmitStatement",
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+                }
+              ]
+            },
+            "documentation": "@dev Internal function to transfer ownership of a given token ID to another address.\nAs opposed to transferFrom, this imposes no restrictions on msg.sender.\n@param from current owner of the token\n@param to address to receive the ownership of the given token ID\n@param tokenId uint256 ID of the token to be transferred",
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+                    "typeString": "address"
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+                      "typeIdentifier": "t_address",
+                      "typeString": "address"
+                    }
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+                    "typeString": "address"
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+                    "name": "address",
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+                      "typeString": "address"
+                    }
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+            "visibility": "internal"
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+                          "name": "to",
+                          "nodeType": "Identifier",
+                          "overloadedDeclarations": [],
+                          "referencedDeclaration": 884,
+                          "src": "23514:2:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_address",
+                            "typeString": "address"
+                          }
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+                        "src": "23514:13:1",
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+                        "name": "bytes4",
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+                          "typeIdentifier": "t_bytes4",
+                          "typeString": "bytes4"
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+                        "expression": {
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+                          "id": 907,
+                          "name": "msg",
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+                          "src": "23630:3:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_magic_message",
+                            "typeString": "msg"
+                          }
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+                        "isLValue": false,
+                        "isPure": false,
+                        "lValueRequested": false,
+                        "memberName": "sender",
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+                        "src": "23630:10:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_address_payable",
+                          "typeString": "address payable"
+                        }
+                      },
+                      {
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+                        "id": 909,
+                        "name": "from",
+                        "nodeType": "Identifier",
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+                        "src": "23642:4:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        }
+                      },
+                      {
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+                        "id": 910,
+                        "name": "tokenId",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
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+                        "src": "23648:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      },
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+                        "id": 911,
+                        "name": "_data",
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+                        "src": "23657:5:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_bytes_memory_ptr",
+                          "typeString": "bytes memory"
+                        }
+                      }
+                    ],
+                    "expression": {
+                      "argumentTypes": [
+                        {
+                          "typeIdentifier": "t_address_payable",
+                          "typeString": "address payable"
+                        },
+                        {
+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        },
+                        {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        },
+                        {
+                          "typeIdentifier": "t_bytes_memory_ptr",
+                          "typeString": "bytes memory"
+                        }
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+                        "arguments": [
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+                            "id": 904,
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+                            "src": "23609:2:1",
+                            "typeDescriptions": {
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+                              "typeString": "address"
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+                              "typeIdentifier": "t_address",
+                              "typeString": "address"
+                            }
+                          ],
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+                          "name": "IERC721Receiver",
+                          "nodeType": "Identifier",
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+                          "referencedDeclaration": 139,
+                          "src": "23593:15:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_type$_t_contract$_IERC721Receiver_$139_$",
+                            "typeString": "type(contract IERC721Receiver)"
+                          }
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+                        "isLValue": false,
+                        "isPure": false,
+                        "kind": "typeConversion",
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+                        "typeDescriptions": {
+                          "typeIdentifier": "t_contract$_IERC721Receiver_$139",
+                          "typeString": "contract IERC721Receiver"
+                        }
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+                      "memberName": "onERC721Received",
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+                      "src": "23593:36:1",
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+                        "typeString": "function (address,address,uint256,bytes memory) external returns (bytes4)"
+                      }
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+                      "typeString": "bytes4"
+                    }
+                  },
+                  "nodeType": "VariableDeclarationStatement",
+                  "src": "23577:86:1"
+                },
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+                    "components": [
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+                        "argumentTypes": null,
+                        "commonType": {
+                          "typeIdentifier": "t_bytes4",
+                          "typeString": "bytes4"
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+                        "lValueRequested": false,
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+                          "name": "retval",
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+                          "overloadedDeclarations": [],
+                          "referencedDeclaration": 902,
+                          "src": "23681:6:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_bytes4",
+                            "typeString": "bytes4"
+                          }
+                        },
+                        "nodeType": "BinaryOperation",
+                        "operator": "==",
+                        "rightExpression": {
+                          "argumentTypes": null,
+                          "id": 915,
+                          "name": "_ERC721_RECEIVED",
+                          "nodeType": "Identifier",
+                          "overloadedDeclarations": [],
+                          "referencedDeclaration": 403,
+                          "src": "23691:16:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_bytes4",
+                            "typeString": "bytes4"
+                          }
+                        },
+                        "src": "23681:26:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_bool",
+                          "typeString": "bool"
+                        }
+                      }
+                    ],
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+                    "isConstant": false,
+                    "isInlineArray": false,
+                    "isLValue": false,
+                    "isPure": false,
+                    "lValueRequested": false,
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+                    "src": "23680:28:1",
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+                  },
+                  "functionReturnParameters": 892,
+                  "id": 918,
+                  "nodeType": "Return",
+                  "src": "23673:35:1"
+                }
+              ]
+            },
+            "documentation": "@dev Internal function to invoke `onERC721Received` on a target address.\nThe call is not executed if the target address is not a contract.\n     * This function is deprecated.\n@param from address representing the previous owner of the given token ID\n@param to target address that will receive the tokens\n@param tokenId uint256 ID of the token to be transferred\n@param _data bytes optional data to send along with the call\n@return bool whether the call correctly returned the expected magic value",
+            "id": 920,
+            "implemented": true,
+            "kind": "function",
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+            "name": "_checkOnERC721Received",
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+                  "scope": 920,
+                  "src": "23400:12:1",
+                  "stateVariable": false,
+                  "storageLocation": "default",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_address",
+                    "typeString": "address"
+                  },
+                  "typeName": {
+                    "id": 881,
+                    "name": "address",
+                    "nodeType": "ElementaryTypeName",
+                    "src": "23400:7:1",
+                    "stateMutability": "nonpayable",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_address",
+                      "typeString": "address"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                },
+                {
+                  "constant": false,
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+                      "src": "27266:10:1",
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+                        "src": "27780:7:1",
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+                          "typeString": "uint256"
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+                          "typeString": "address"
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+                          "typeString": "address"
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+                        {
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+                          "typeString": "uint256"
+                        }
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+                      "typeString": "tuple()"
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+                        "nodeType": "Identifier",
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+                        "src": "28342:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
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+                        {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
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+                      "name": "_addTokenToAllTokensEnumeration",
+                      "nodeType": "Identifier",
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+                      "src": "28310:31:1",
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+                        "typeString": "function (uint256)"
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+                }
+              ]
+            },
+            "documentation": "@dev Internal function to mint a new token.\nReverts if the given token ID already exists.\n@param to address the beneficiary that will own the minted token\n@param tokenId uint256 ID of the token to be minted",
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+                  "stateVariable": false,
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+                    "typeString": "address"
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+                    "name": "address",
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+                      "typeIdentifier": "t_address",
+                      "typeString": "address"
+                    }
+                  },
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+                  "src": "28188:15:1",
+                  "stateVariable": false,
+                  "storageLocation": "default",
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+                    "typeString": "uint256"
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+                      "typeString": "uint256"
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+                  "visibility": "internal"
+                }
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+            "visibility": "internal"
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+                        "name": "owner",
+                        "nodeType": "Identifier",
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+                        "src": "28710:5:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        }
+                      },
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+                        "id": 1120,
+                        "name": "tokenId",
+                        "nodeType": "Identifier",
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+                        "referencedDeclaration": 1113,
+                        "src": "28717:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
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+                      "argumentTypes": [
+                        {
+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        },
+                        {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      ],
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+                        "id": 1116,
+                        "name": "super",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 1572,
+                        "src": "28698:5:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_super$_ERC721Enumerable_$1302",
+                          "typeString": "contract super ERC721Enumerable"
+                        }
+                      },
+                      "id": 1118,
+                      "isConstant": false,
+                      "isLValue": false,
+                      "isPure": false,
+                      "lValueRequested": false,
+                      "memberName": "_burn",
+                      "nodeType": "MemberAccess",
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+                      "src": "28698:11:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_function_internal_nonpayable$_t_address_$_t_uint256_$returns$__$",
+                        "typeString": "function (address,uint256)"
+                      }
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+                    "kind": "functionCall",
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+                    "nodeType": "FunctionCall",
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+                      "typeString": "tuple()"
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+                        "id": 1124,
+                        "name": "owner",
+                        "nodeType": "Identifier",
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+                        "src": "28769:5:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        }
+                      },
+                      {
+                        "argumentTypes": null,
+                        "id": 1125,
+                        "name": "tokenId",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 1113,
+                        "src": "28776:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      }
+                    ],
+                    "expression": {
+                      "argumentTypes": [
+                        {
+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        },
+                        {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      ],
+                      "id": 1123,
+                      "name": "_removeTokenFromOwnerEnumeration",
+                      "nodeType": "Identifier",
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+                      "referencedDeclaration": 1252,
+                      "src": "28736:32:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_function_internal_nonpayable$_t_address_$_t_uint256_$returns$__$",
+                        "typeString": "function (address,uint256)"
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+                    "isLValue": false,
+                    "isPure": false,
+                    "kind": "functionCall",
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+                    "nodeType": "FunctionCall",
+                    "src": "28736:48:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_tuple$__$",
+                      "typeString": "tuple()"
+                    }
+                  },
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+                  "nodeType": "ExpressionStatement",
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+                },
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+                      "baseExpression": {
+                        "argumentTypes": null,
+                        "id": 1128,
+                        "name": "_ownedTokensIndex",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 985,
+                        "src": "28903:17:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_mapping$_t_uint256_$_t_uint256_$",
+                          "typeString": "mapping(uint256 => uint256)"
+                        }
+                      },
+                      "id": 1130,
+                      "indexExpression": {
+                        "argumentTypes": null,
+                        "id": 1129,
+                        "name": "tokenId",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 1113,
+                        "src": "28921:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      },
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+                      "isLValue": true,
+                      "isPure": false,
+                      "lValueRequested": true,
+                      "nodeType": "IndexAccess",
+                      "src": "28903:26:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_uint256",
+                        "typeString": "uint256"
+                      }
+                    },
+                    "nodeType": "Assignment",
+                    "operator": "=",
+                    "rightHandSide": {
+                      "argumentTypes": null,
+                      "hexValue": "30",
+                      "id": 1131,
+                      "isConstant": false,
+                      "isLValue": false,
+                      "isPure": true,
+                      "kind": "number",
+                      "lValueRequested": false,
+                      "nodeType": "Literal",
+                      "src": "28932:1:1",
+                      "subdenomination": null,
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_rational_0_by_1",
+                        "typeString": "int_const 0"
+                      },
+                      "value": "0"
+                    },
+                    "src": "28903:30:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_uint256",
+                      "typeString": "uint256"
+                    }
+                  },
+                  "id": 1133,
+                  "nodeType": "ExpressionStatement",
+                  "src": "28903:30:1"
+                },
+                {
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+                    "arguments": [
+                      {
+                        "argumentTypes": null,
+                        "id": 1135,
+                        "name": "tokenId",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 1113,
+                        "src": "28981:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      }
+                    ],
+                    "expression": {
+                      "argumentTypes": [
+                        {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      ],
+                      "id": 1134,
+                      "name": "_removeTokenFromAllTokensEnumeration",
+                      "nodeType": "Identifier",
+                      "overloadedDeclarations": [],
+                      "referencedDeclaration": 1301,
+                      "src": "28944:36:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_function_internal_nonpayable$_t_uint256_$returns$__$",
+                        "typeString": "function (uint256)"
+                      }
+                    },
+                    "id": 1136,
+                    "isConstant": false,
+                    "isLValue": false,
+                    "isPure": false,
+                    "kind": "functionCall",
+                    "lValueRequested": false,
+                    "names": [],
+                    "nodeType": "FunctionCall",
+                    "src": "28944:45:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_tuple$__$",
+                      "typeString": "tuple()"
+                    }
+                  },
+                  "id": 1137,
+                  "nodeType": "ExpressionStatement",
+                  "src": "28944:45:1"
+                }
+              ]
+            },
+            "documentation": "@dev Internal function to burn a specific token.\nReverts if the token does not exist.\nDeprecated, use _burn(uint256) instead.\n@param owner owner of the token to burn\n@param tokenId uint256 ID of the token being burned",
+            "id": 1139,
+            "implemented": true,
+            "kind": "function",
+            "modifiers": [],
+            "name": "_burn",
+            "nodeType": "FunctionDefinition",
+            "parameters": {
+              "id": 1114,
+              "nodeType": "ParameterList",
+              "parameters": [
+                {
+                  "constant": false,
+                  "id": 1111,
+                  "name": "owner",
+                  "nodeType": "VariableDeclaration",
+                  "scope": 1139,
+                  "src": "28647:13:1",
+                  "stateVariable": false,
+                  "storageLocation": "default",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_address",
+                    "typeString": "address"
+                  },
+                  "typeName": {
+                    "id": 1110,
+                    "name": "address",
+                    "nodeType": "ElementaryTypeName",
+                    "src": "28647:7:1",
+                    "stateMutability": "nonpayable",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_address",
+                      "typeString": "address"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                },
+                {
+                  "constant": false,
+                  "id": 1113,
+                  "name": "tokenId",
+                  "nodeType": "VariableDeclaration",
+                  "scope": 1139,
+                  "src": "28662:15:1",
+                  "stateVariable": false,
+                  "storageLocation": "default",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_uint256",
+                    "typeString": "uint256"
+                  },
+                  "typeName": {
+                    "id": 1112,
+                    "name": "uint256",
+                    "nodeType": "ElementaryTypeName",
+                    "src": "28662:7:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_uint256",
+                      "typeString": "uint256"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                }
+              ],
+              "src": "28646:32:1"
+            },
+            "returnParameters": {
+              "id": 1115,
+              "nodeType": "ParameterList",
+              "parameters": [],
+              "src": "28688:0:1"
+            },
+            "scope": 1302,
+            "src": "28632:364:1",
+            "stateMutability": "nonpayable",
+            "superFunction": 811,
+            "visibility": "internal"
+          },
+          {
+            "body": {
+              "id": 1151,
+              "nodeType": "Block",
+              "src": "29282:43:1",
+              "statements": [
+                {
+                  "expression": {
+                    "argumentTypes": null,
+                    "baseExpression": {
+                      "argumentTypes": null,
+                      "id": 1147,
+                      "name": "_ownedTokens",
+                      "nodeType": "Identifier",
+                      "overloadedDeclarations": [],
+                      "referencedDeclaration": 981,
+                      "src": "29299:12:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_mapping$_t_address_$_t_array$_t_uint256_$dyn_storage_$",
+                        "typeString": "mapping(address => uint256[] storage ref)"
+                      }
+                    },
+                    "id": 1149,
+                    "indexExpression": {
+                      "argumentTypes": null,
+                      "id": 1148,
+                      "name": "owner",
+                      "nodeType": "Identifier",
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+                      "referencedDeclaration": 1141,
+                      "src": "29312:5:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_address",
+                        "typeString": "address"
+                      }
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+                    "isLValue": true,
+                    "isPure": false,
+                    "lValueRequested": false,
+                    "nodeType": "IndexAccess",
+                    "src": "29299:19:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_array$_t_uint256_$dyn_storage",
+                      "typeString": "uint256[] storage ref"
+                    }
+                  },
+                  "functionReturnParameters": 1146,
+                  "id": 1150,
+                  "nodeType": "Return",
+                  "src": "29292:26:1"
+                }
+              ]
+            },
+            "documentation": "@dev Gets the list of token IDs of the requested owner.\n@param owner address owning the tokens\n@return uint256[] List of token IDs owned by the requested address",
+            "id": 1152,
+            "implemented": true,
+            "kind": "function",
+            "modifiers": [],
+            "name": "_tokensOfOwner",
+            "nodeType": "FunctionDefinition",
+            "parameters": {
+              "id": 1142,
+              "nodeType": "ParameterList",
+              "parameters": [
+                {
+                  "constant": false,
+                  "id": 1141,
+                  "name": "owner",
+                  "nodeType": "VariableDeclaration",
+                  "scope": 1152,
+                  "src": "29225:13:1",
+                  "stateVariable": false,
+                  "storageLocation": "default",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_address",
+                    "typeString": "address"
+                  },
+                  "typeName": {
+                    "id": 1140,
+                    "name": "address",
+                    "nodeType": "ElementaryTypeName",
+                    "src": "29225:7:1",
+                    "stateMutability": "nonpayable",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_address",
+                      "typeString": "address"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                }
+              ],
+              "src": "29224:15:1"
+            },
+            "returnParameters": {
+              "id": 1146,
+              "nodeType": "ParameterList",
+              "parameters": [
+                {
+                  "constant": false,
+                  "id": 1145,
+                  "name": "",
+                  "nodeType": "VariableDeclaration",
+                  "scope": 1152,
+                  "src": "29263:17:1",
+                  "stateVariable": false,
+                  "storageLocation": "storage",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_array$_t_uint256_$dyn_storage_ptr",
+                    "typeString": "uint256[]"
+                  },
+                  "typeName": {
+                    "baseType": {
+                      "id": 1143,
+                      "name": "uint256",
+                      "nodeType": "ElementaryTypeName",
+                      "src": "29263:7:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_uint256",
+                        "typeString": "uint256"
+                      }
+                    },
+                    "id": 1144,
+                    "length": null,
+                    "nodeType": "ArrayTypeName",
+                    "src": "29263:9:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_array$_t_uint256_$dyn_storage_ptr",
+                      "typeString": "uint256[]"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                }
+              ],
+              "src": "29262:19:1"
+            },
+            "scope": 1302,
+            "src": "29201:124:1",
+            "stateMutability": "view",
+            "superFunction": null,
+            "visibility": "internal"
+          },
+          {
+            "body": {
+              "id": 1175,
+              "nodeType": "Block",
+              "src": "29693:109:1",
+              "statements": [
+                {
+                  "expression": {
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+                    "id": 1166,
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+                    "isLValue": false,
+                    "isPure": false,
+                    "lValueRequested": false,
+                    "leftHandSide": {
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+                      "baseExpression": {
+                        "argumentTypes": null,
+                        "id": 1159,
+                        "name": "_ownedTokensIndex",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 985,
+                        "src": "29703:17:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_mapping$_t_uint256_$_t_uint256_$",
+                          "typeString": "mapping(uint256 => uint256)"
+                        }
+                      },
+                      "id": 1161,
+                      "indexExpression": {
+                        "argumentTypes": null,
+                        "id": 1160,
+                        "name": "tokenId",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 1156,
+                        "src": "29721:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
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+                      "isLValue": true,
+                      "isPure": false,
+                      "lValueRequested": true,
+                      "nodeType": "IndexAccess",
+                      "src": "29703:26:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_uint256",
+                        "typeString": "uint256"
+                      }
+                    },
+                    "nodeType": "Assignment",
+                    "operator": "=",
+                    "rightHandSide": {
+                      "argumentTypes": null,
+                      "expression": {
+                        "argumentTypes": null,
+                        "baseExpression": {
+                          "argumentTypes": null,
+                          "id": 1162,
+                          "name": "_ownedTokens",
+                          "nodeType": "Identifier",
+                          "overloadedDeclarations": [],
+                          "referencedDeclaration": 981,
+                          "src": "29732:12:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_mapping$_t_address_$_t_array$_t_uint256_$dyn_storage_$",
+                            "typeString": "mapping(address => uint256[] storage ref)"
+                          }
+                        },
+                        "id": 1164,
+                        "indexExpression": {
+                          "argumentTypes": null,
+                          "id": 1163,
+                          "name": "to",
+                          "nodeType": "Identifier",
+                          "overloadedDeclarations": [],
+                          "referencedDeclaration": 1154,
+                          "src": "29745:2:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_address",
+                            "typeString": "address"
+                          }
+                        },
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+                              "typeDescriptions": {
+                                "typeIdentifier": "t_mapping$_t_address_$_t_array$_t_uint256_$dyn_storage_$",
+                                "typeString": "mapping(address => uint256[] storage ref)"
+                              }
+                            },
+                            "id": 1225,
+                            "indexExpression": {
+                              "argumentTypes": null,
+                              "id": 1224,
+                              "name": "from",
+                              "nodeType": "Identifier",
+                              "overloadedDeclarations": [],
+                              "referencedDeclaration": 1197,
+                              "src": "31332:4:1",
+                              "typeDescriptions": {
+                                "typeIdentifier": "t_address",
+                                "typeString": "address"
+                              }
+                            },
+                            "isConstant": false,
+                            "isLValue": true,
+                            "isPure": false,
+                            "lValueRequested": false,
+                            "nodeType": "IndexAccess",
+                            "src": "31319:18:1",
+                            "typeDescriptions": {
+                              "typeIdentifier": "t_array$_t_uint256_$dyn_storage",
+                              "typeString": "uint256[] storage ref"
+                            }
+                          },
+                          "id": 1227,
+                          "indexExpression": {
+                            "argumentTypes": null,
+                            "id": 1226,
+                            "name": "lastTokenIndex",
+                            "nodeType": "Identifier",
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+                            "referencedDeclaration": 1203,
+                            "src": "31338:14:1",
+                            "typeDescriptions": {
+                              "typeIdentifier": "t_uint256",
+                              "typeString": "uint256"
+                            }
+                          },
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+                          "isLValue": true,
+                          "isPure": false,
+                          "lValueRequested": false,
+                          "nodeType": "IndexAccess",
+                          "src": "31319:34:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_uint256",
+                            "typeString": "uint256"
+                          }
+                        },
+                        "nodeType": "VariableDeclarationStatement",
+                        "src": "31297:56:1"
+                      },
+                      {
+                        "expression": {
+                          "argumentTypes": null,
+                          "id": 1235,
+                          "isConstant": false,
+                          "isLValue": false,
+                          "isPure": false,
+                          "lValueRequested": false,
+                          "leftHandSide": {
+                            "argumentTypes": null,
+                            "baseExpression": {
+                              "argumentTypes": null,
+                              "baseExpression": {
+                                "argumentTypes": null,
+                                "id": 1229,
+                                "name": "_ownedTokens",
+                                "nodeType": "Identifier",
+                                "overloadedDeclarations": [],
+                                "referencedDeclaration": 981,
+                                "src": "31368:12:1",
+                                "typeDescriptions": {
+                                  "typeIdentifier": "t_mapping$_t_address_$_t_array$_t_uint256_$dyn_storage_$",
+                                  "typeString": "mapping(address => uint256[] storage ref)"
+                                }
+                              },
+                              "id": 1232,
+                              "indexExpression": {
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+                                "id": 1230,
+                                "name": "from",
+                                "nodeType": "Identifier",
+                                "overloadedDeclarations": [],
+                                "referencedDeclaration": 1197,
+                                "src": "31381:4:1",
+                                "typeDescriptions": {
+                                  "typeIdentifier": "t_address",
+                                  "typeString": "address"
+                                }
+                              },
+                              "isConstant": false,
+                              "isLValue": true,
+                              "isPure": false,
+                              "lValueRequested": false,
+                              "nodeType": "IndexAccess",
+                              "src": "31368:18:1",
+                              "typeDescriptions": {
+                                "typeIdentifier": "t_array$_t_uint256_$dyn_storage",
+                                "typeString": "uint256[] storage ref"
+                              }
+                            },
+                            "id": 1233,
+                            "indexExpression": {
+                              "argumentTypes": null,
+                              "id": 1231,
+                              "name": "tokenIndex",
+                              "nodeType": "Identifier",
+                              "overloadedDeclarations": [],
+                              "referencedDeclaration": 1213,
+                              "src": "31387:10:1",
+                              "typeDescriptions": {
+                                "typeIdentifier": "t_uint256",
+                                "typeString": "uint256"
+                              }
+                            },
+                            "isConstant": false,
+                            "isLValue": true,
+                            "isPure": false,
+                            "lValueRequested": true,
+                            "nodeType": "IndexAccess",
+                            "src": "31368:30:1",
+                            "typeDescriptions": {
+                              "typeIdentifier": "t_uint256",
+                              "typeString": "uint256"
+                            }
+                          },
+                          "nodeType": "Assignment",
+                          "operator": "=",
+                          "rightHandSide": {
+                            "argumentTypes": null,
+                            "id": 1234,
+                            "name": "lastTokenId",
+                            "nodeType": "Identifier",
+                            "overloadedDeclarations": [],
+                            "referencedDeclaration": 1222,
+                            "src": "31401:11:1",
+                            "typeDescriptions": {
+                              "typeIdentifier": "t_uint256",
+                              "typeString": "uint256"
+                            }
+                          },
+                          "src": "31368:44:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_uint256",
+                            "typeString": "uint256"
+                          }
+                        },
+                        "id": 1236,
+                        "nodeType": "ExpressionStatement",
+                        "src": "31368:44:1"
+                      },
+                      {
+                        "expression": {
+                          "argumentTypes": null,
+                          "id": 1241,
+                          "isConstant": false,
+                          "isLValue": false,
+                          "isPure": false,
+                          "lValueRequested": false,
+                          "leftHandSide": {
+                            "argumentTypes": null,
+                            "baseExpression": {
+                              "argumentTypes": null,
+                              "id": 1237,
+                              "name": "_ownedTokensIndex",
+                              "nodeType": "Identifier",
+                              "overloadedDeclarations": [],
+                              "referencedDeclaration": 985,
+                              "src": "31484:17:1",
+                              "typeDescriptions": {
+                                "typeIdentifier": "t_mapping$_t_uint256_$_t_uint256_$",
+                                "typeString": "mapping(uint256 => uint256)"
+                              }
+                            },
+                            "id": 1239,
+                            "indexExpression": {
+                              "argumentTypes": null,
+                              "id": 1238,
+                              "name": "lastTokenId",
+                              "nodeType": "Identifier",
+                              "overloadedDeclarations": [],
+                              "referencedDeclaration": 1222,
+                              "src": "31502:11:1",
+                              "typeDescriptions": {
+                                "typeIdentifier": "t_uint256",
+                                "typeString": "uint256"
+                              }
+                            },
+                            "isConstant": false,
+                            "isLValue": true,
+                            "isPure": false,
+                            "lValueRequested": true,
+                            "nodeType": "IndexAccess",
+                            "src": "31484:30:1",
+                            "typeDescriptions": {
+                              "typeIdentifier": "t_uint256",
+                              "typeString": "uint256"
+                            }
+                          },
+                          "nodeType": "Assignment",
+                          "operator": "=",
+                          "rightHandSide": {
+                            "argumentTypes": null,
+                            "id": 1240,
+                            "name": "tokenIndex",
+                            "nodeType": "Identifier",
+                            "overloadedDeclarations": [],
+                            "referencedDeclaration": 1213,
+                            "src": "31517:10:1",
+                            "typeDescriptions": {
+                              "typeIdentifier": "t_uint256",
+                              "typeString": "uint256"
+                            }
+                          },
+                          "src": "31484:43:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_uint256",
+                            "typeString": "uint256"
+                          }
+                        },
+                        "id": 1242,
+                        "nodeType": "ExpressionStatement",
+                        "src": "31484:43:1"
+                      }
+                    ]
+                  }
+                },
+                {
+                  "expression": {
+                    "argumentTypes": null,
+                    "id": 1249,
+                    "isConstant": false,
+                    "isLValue": false,
+                    "isPure": false,
+                    "lValueRequested": false,
+                    "nodeType": "UnaryOperation",
+                    "operator": "--",
+                    "prefix": false,
+                    "src": "31658:27:1",
+                    "subExpression": {
+                      "argumentTypes": null,
+                      "expression": {
+                        "argumentTypes": null,
+                        "baseExpression": {
+                          "argumentTypes": null,
+                          "id": 1245,
+                          "name": "_ownedTokens",
+                          "nodeType": "Identifier",
+                          "overloadedDeclarations": [],
+                          "referencedDeclaration": 981,
+                          "src": "31658:12:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_mapping$_t_address_$_t_array$_t_uint256_$dyn_storage_$",
+                            "typeString": "mapping(address => uint256[] storage ref)"
+                          }
+                        },
+                        "id": 1247,
+                        "indexExpression": {
+                          "argumentTypes": null,
+                          "id": 1246,
+                          "name": "from",
+                          "nodeType": "Identifier",
+                          "overloadedDeclarations": [],
+                          "referencedDeclaration": 1197,
+                          "src": "31671:4:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_address",
+                            "typeString": "address"
+                          }
+                        },
+                        "isConstant": false,
+                        "isLValue": true,
+                        "isPure": false,
+                        "lValueRequested": false,
+                        "nodeType": "IndexAccess",
+                        "src": "31658:18:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_array$_t_uint256_$dyn_storage",
+                          "typeString": "uint256[] storage ref"
+                        }
+                      },
+                      "id": 1248,
+                      "isConstant": false,
+                      "isLValue": true,
+                      "isPure": false,
+                      "lValueRequested": true,
+                      "memberName": "length",
+                      "nodeType": "MemberAccess",
+                      "referencedDeclaration": null,
+                      "src": "31658:25:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_uint256",
+                        "typeString": "uint256"
+                      }
+                    },
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_uint256",
+                      "typeString": "uint256"
+                    }
+                  },
+                  "id": 1250,
+                  "nodeType": "ExpressionStatement",
+                  "src": "31658:27:1"
+                }
+              ]
+            },
+            "documentation": "@dev Private function to remove a token from this extension's ownership-tracking data structures. Note that\nwhile the token is not assigned a new owner, the _ownedTokensIndex mapping is _not_ updated: this allows for\ngas optimizations e.g. when performing a transfer operation (avoiding double writes).\nThis has O(1) time complexity, but alters the order of the _ownedTokens array.\n@param from address representing the previous owner of the given token ID\n@param tokenId uint256 ID of the token to be removed from the tokens list of the given address",
+            "id": 1252,
+            "implemented": true,
+            "kind": "function",
+            "modifiers": [],
+            "name": "_removeTokenFromOwnerEnumeration",
+            "nodeType": "FunctionDefinition",
+            "parameters": {
+              "id": 1200,
+              "nodeType": "ParameterList",
+              "parameters": [
+                {
+                  "constant": false,
+                  "id": 1197,
+                  "name": "from",
+                  "nodeType": "VariableDeclaration",
+                  "scope": 1252,
+                  "src": "30815:12:1",
+                  "stateVariable": false,
+                  "storageLocation": "default",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_address",
+                    "typeString": "address"
+                  },
+                  "typeName": {
+                    "id": 1196,
+                    "name": "address",
+                    "nodeType": "ElementaryTypeName",
+                    "src": "30815:7:1",
+                    "stateMutability": "nonpayable",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_address",
+                      "typeString": "address"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                },
+                {
+                  "constant": false,
+                  "id": 1199,
+                  "name": "tokenId",
+                  "nodeType": "VariableDeclaration",
+                  "scope": 1252,
+                  "src": "30829:15:1",
+                  "stateVariable": false,
+                  "storageLocation": "default",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_uint256",
+                    "typeString": "uint256"
+                  },
+                  "typeName": {
+                    "id": 1198,
+                    "name": "uint256",
+                    "nodeType": "ElementaryTypeName",
+                    "src": "30829:7:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_uint256",
+                      "typeString": "uint256"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                }
+              ],
+              "src": "30814:31:1"
+            },
+            "returnParameters": {
+              "id": 1201,
+              "nodeType": "ParameterList",
+              "parameters": [],
+              "src": "30854:0:1"
+            },
+            "scope": 1302,
+            "src": "30773:1128:1",
+            "stateMutability": "nonpayable",
+            "superFunction": null,
+            "visibility": "private"
+          },
+          {
+            "body": {
+              "id": 1300,
+              "nodeType": "Block",
+              "src": "32260:993:1",
+              "statements": [
+                {
+                  "assignments": [
+                    1258
+                  ],
+                  "declarations": [
+                    {
+                      "constant": false,
+                      "id": 1258,
+                      "name": "lastTokenIndex",
+                      "nodeType": "VariableDeclaration",
+                      "scope": 1300,
+                      "src": "32438:22:1",
+                      "stateVariable": false,
+                      "storageLocation": "default",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_uint256",
+                        "typeString": "uint256"
+                      },
+                      "typeName": {
+                        "id": 1257,
+                        "name": "uint256",
+                        "nodeType": "ElementaryTypeName",
+                        "src": "32438:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      },
+                      "value": null,
+                      "visibility": "internal"
+                    }
+                  ],
+                  "id": 1264,
+                  "initialValue": {
+                    "argumentTypes": null,
+                    "arguments": [
+                      {
+                        "argumentTypes": null,
+                        "hexValue": "31",
+                        "id": 1262,
+                        "isConstant": false,
+                        "isLValue": false,
+                        "isPure": true,
+                        "kind": "number",
+                        "lValueRequested": false,
+                        "nodeType": "Literal",
+                        "src": "32485:1:1",
+                        "subdenomination": null,
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_rational_1_by_1",
+                          "typeString": "int_const 1"
+                        },
+                        "value": "1"
+                      }
+                    ],
+                    "expression": {
+                      "argumentTypes": [
+                        {
+                          "typeIdentifier": "t_rational_1_by_1",
+                          "typeString": "int_const 1"
+                        }
+                      ],
+                      "expression": {
+                        "argumentTypes": null,
+                        "expression": {
+                          "argumentTypes": null,
+                          "id": 1259,
+                          "name": "_allTokens",
+                          "nodeType": "Identifier",
+                          "overloadedDeclarations": [],
+                          "referencedDeclaration": 988,
+                          "src": "32463:10:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_array$_t_uint256_$dyn_storage",
+                            "typeString": "uint256[] storage ref"
+                          }
+                        },
+                        "id": 1260,
+                        "isConstant": false,
+                        "isLValue": true,
+                        "isPure": false,
+                        "lValueRequested": false,
+                        "memberName": "length",
+                        "nodeType": "MemberAccess",
+                        "referencedDeclaration": null,
+                        "src": "32463:17:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      },
+                      "id": 1261,
+                      "isConstant": false,
+                      "isLValue": false,
+                      "isPure": false,
+                      "lValueRequested": false,
+                      "memberName": "sub",
+                      "nodeType": "MemberAccess",
+                      "referencedDeclaration": 190,
+                      "src": "32463:21:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_function_internal_pure$_t_uint256_$_t_uint256_$returns$_t_uint256_$bound_to$_t_uint256_$",
+                        "typeString": "function (uint256,uint256) pure returns (uint256)"
+                      }
+                    },
+                    "id": 1263,
+                    "isConstant": false,
+                    "isLValue": false,
+                    "isPure": false,
+                    "kind": "functionCall",
+                    "lValueRequested": false,
+                    "names": [],
+                    "nodeType": "FunctionCall",
+                    "src": "32463:24:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_uint256",
+                      "typeString": "uint256"
+                    }
+                  },
+                  "nodeType": "VariableDeclarationStatement",
+                  "src": "32438:49:1"
+                },
+                {
+                  "assignments": [
+                    1266
+                  ],
+                  "declarations": [
+                    {
+                      "constant": false,
+                      "id": 1266,
+                      "name": "tokenIndex",
+                      "nodeType": "VariableDeclaration",
+                      "scope": 1300,
+                      "src": "32497:18:1",
+                      "stateVariable": false,
+                      "storageLocation": "default",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_uint256",
+                        "typeString": "uint256"
+                      },
+                      "typeName": {
+                        "id": 1265,
+                        "name": "uint256",
+                        "nodeType": "ElementaryTypeName",
+                        "src": "32497:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      },
+                      "value": null,
+                      "visibility": "internal"
+                    }
+                  ],
+                  "id": 1270,
+                  "initialValue": {
+                    "argumentTypes": null,
+                    "baseExpression": {
+                      "argumentTypes": null,
+                      "id": 1267,
+                      "name": "_allTokensIndex",
+                      "nodeType": "Identifier",
+                      "overloadedDeclarations": [],
+                      "referencedDeclaration": 992,
+                      "src": "32518:15:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_mapping$_t_uint256_$_t_uint256_$",
+                        "typeString": "mapping(uint256 => uint256)"
+                      }
+                    },
+                    "id": 1269,
+                    "indexExpression": {
+                      "argumentTypes": null,
+                      "id": 1268,
+                      "name": "tokenId",
+                      "nodeType": "Identifier",
+                      "overloadedDeclarations": [],
+                      "referencedDeclaration": 1254,
+                      "src": "32534:7:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_uint256",
+                        "typeString": "uint256"
+                      }
+                    },
+                    "isConstant": false,
+                    "isLValue": true,
+                    "isPure": false,
+                    "lValueRequested": false,
+                    "nodeType": "IndexAccess",
+                    "src": "32518:24:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_uint256",
+                      "typeString": "uint256"
+                    }
+                  },
+                  "nodeType": "VariableDeclarationStatement",
+                  "src": "32497:45:1"
+                },
+                {
+                  "assignments": [
+                    1272
+                  ],
+                  "declarations": [
+                    {
+                      "constant": false,
+                      "id": 1272,
+                      "name": "lastTokenId",
+                      "nodeType": "VariableDeclaration",
+                      "scope": 1300,
+                      "src": "32864:19:1",
+                      "stateVariable": false,
+                      "storageLocation": "default",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_uint256",
+                        "typeString": "uint256"
+                      },
+                      "typeName": {
+                        "id": 1271,
+                        "name": "uint256",
+                        "nodeType": "ElementaryTypeName",
+                        "src": "32864:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      },
+                      "value": null,
+                      "visibility": "internal"
+                    }
+                  ],
+                  "id": 1276,
+                  "initialValue": {
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+                    "baseExpression": {
+                      "argumentTypes": null,
+                      "id": 1273,
+                      "name": "_allTokens",
+                      "nodeType": "Identifier",
+                      "overloadedDeclarations": [],
+                      "referencedDeclaration": 988,
+                      "src": "32886:10:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_array$_t_uint256_$dyn_storage",
+                        "typeString": "uint256[] storage ref"
+                      }
+                    },
+                    "id": 1275,
+                    "indexExpression": {
+                      "argumentTypes": null,
+                      "id": 1274,
+                      "name": "lastTokenIndex",
+                      "nodeType": "Identifier",
+                      "overloadedDeclarations": [],
+                      "referencedDeclaration": 1258,
+                      "src": "32897:14:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_uint256",
+                        "typeString": "uint256"
+                      }
+                    },
+                    "isConstant": false,
+                    "isLValue": true,
+                    "isPure": false,
+                    "lValueRequested": false,
+                    "nodeType": "IndexAccess",
+                    "src": "32886:26:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_uint256",
+                      "typeString": "uint256"
+                    }
+                  },
+                  "nodeType": "VariableDeclarationStatement",
+                  "src": "32864:48:1"
+                },
+                {
+                  "expression": {
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+                    "id": 1281,
+                    "isConstant": false,
+                    "isLValue": false,
+                    "isPure": false,
+                    "lValueRequested": false,
+                    "leftHandSide": {
+                      "argumentTypes": null,
+                      "baseExpression": {
+                        "argumentTypes": null,
+                        "id": 1277,
+                        "name": "_allTokens",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 988,
+                        "src": "32923:10:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_array$_t_uint256_$dyn_storage",
+                          "typeString": "uint256[] storage ref"
+                        }
+                      },
+                      "id": 1279,
+                      "indexExpression": {
+                        "argumentTypes": null,
+                        "id": 1278,
+                        "name": "tokenIndex",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 1266,
+                        "src": "32934:10:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      },
+                      "isConstant": false,
+                      "isLValue": true,
+                      "isPure": false,
+                      "lValueRequested": true,
+                      "nodeType": "IndexAccess",
+                      "src": "32923:22:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_uint256",
+                        "typeString": "uint256"
+                      }
+                    },
+                    "nodeType": "Assignment",
+                    "operator": "=",
+                    "rightHandSide": {
+                      "argumentTypes": null,
+                      "id": 1280,
+                      "name": "lastTokenId",
+                      "nodeType": "Identifier",
+                      "overloadedDeclarations": [],
+                      "referencedDeclaration": 1272,
+                      "src": "32948:11:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_uint256",
+                        "typeString": "uint256"
+                      }
+                    },
+                    "src": "32923:36:1",
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+              "name": "IERC165",
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+                "typeString": "contract IERC165"
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+                          "typeString": "bytes memory"
+                        }
+                      }
+                    ],
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+                          "typeString": "address payable"
+                        },
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+                          "typeString": "address"
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+                            }
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+                          "name": "IERC721Receiver",
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+                          "src": "23593:15:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_type$_t_contract$_IERC721Receiver_$139_$",
+                            "typeString": "type(contract IERC721Receiver)"
+                          }
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+                          "typeDescriptions": {
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+                            "typeString": "bytes4"
+                          }
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+              ]
+            },
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+                        "src": "23940:15:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_mapping$_t_uint256_$_t_address_$",
+                          "typeString": "mapping(uint256 => address)"
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+                              "src": "23994:15:1",
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+                                "kind": "number",
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+                                "nodeType": "Literal",
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+                                  "typeString": "int_const 0"
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+                            ],
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+                              "isConstant": false,
+                              "isLValue": false,
+                              "isPure": true,
+                              "lValueRequested": false,
+                              "nodeType": "ElementaryTypeNameExpression",
+                              "src": "24021:7:1",
+                              "typeDescriptions": {
+                                "typeIdentifier": "t_type$_t_address_$",
+                                "typeString": "type(address)"
+                              },
+                              "typeName": "address"
+                            },
+                            "id": 937,
+                            "isConstant": false,
+                            "isLValue": false,
+                            "isPure": true,
+                            "kind": "typeConversion",
+                            "lValueRequested": false,
+                            "names": [],
+                            "nodeType": "FunctionCall",
+                            "src": "24021:10:1",
+                            "typeDescriptions": {
+                              "typeIdentifier": "t_address_payable",
+                              "typeString": "address payable"
+                            }
+                          },
+                          "src": "23994:37:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_address",
+                            "typeString": "address"
+                          }
+                        },
+                        "id": 939,
+                        "nodeType": "ExpressionStatement",
+                        "src": "23994:37:1"
+                      }
+                    ]
+                  }
+                }
+              ]
+            },
+            "documentation": "@dev Private function to clear current approval of a given token ID.\n@param tokenId uint256 ID of the token to be transferred",
+            "id": 943,
+            "implemented": true,
+            "kind": "function",
+            "modifiers": [],
+            "name": "_clearApproval",
+            "nodeType": "FunctionDefinition",
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+              "nodeType": "ParameterList",
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+                  "stateVariable": false,
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+                    "name": "uint256",
+                    "nodeType": "ElementaryTypeName",
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+                      "typeString": "uint256"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                }
+              ],
+              "src": "23900:17:1"
+            },
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+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      }
+                    ],
+                    "expression": {
+                      "argumentTypes": [
+                        {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      ],
+                      "id": 1134,
+                      "name": "_removeTokenFromAllTokensEnumeration",
+                      "nodeType": "Identifier",
+                      "overloadedDeclarations": [],
+                      "referencedDeclaration": 1301,
+                      "src": "28944:36:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_function_internal_nonpayable$_t_uint256_$returns$__$",
+                        "typeString": "function (uint256)"
+                      }
+                    },
+                    "id": 1136,
+                    "isConstant": false,
+                    "isLValue": false,
+                    "isPure": false,
+                    "kind": "functionCall",
+                    "lValueRequested": false,
+                    "names": [],
+                    "nodeType": "FunctionCall",
+                    "src": "28944:45:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_tuple$__$",
+                      "typeString": "tuple()"
+                    }
+                  },
+                  "id": 1137,
+                  "nodeType": "ExpressionStatement",
+                  "src": "28944:45:1"
+                }
+              ]
+            },
+            "documentation": "@dev Internal function to burn a specific token.\nReverts if the token does not exist.\nDeprecated, use _burn(uint256) instead.\n@param owner owner of the token to burn\n@param tokenId uint256 ID of the token being burned",
+            "id": 1139,
+            "implemented": true,
+            "kind": "function",
+            "modifiers": [],
+            "name": "_burn",
+            "nodeType": "FunctionDefinition",
+            "parameters": {
+              "id": 1114,
+              "nodeType": "ParameterList",
+              "parameters": [
+                {
+                  "constant": false,
+                  "id": 1111,
+                  "name": "owner",
+                  "nodeType": "VariableDeclaration",
+                  "scope": 1139,
+                  "src": "28647:13:1",
+                  "stateVariable": false,
+                  "storageLocation": "default",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_address",
+                    "typeString": "address"
+                  },
+                  "typeName": {
+                    "id": 1110,
+                    "name": "address",
+                    "nodeType": "ElementaryTypeName",
+                    "src": "28647:7:1",
+                    "stateMutability": "nonpayable",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_address",
+                      "typeString": "address"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                },
+                {
+                  "constant": false,
+                  "id": 1113,
+                  "name": "tokenId",
+                  "nodeType": "VariableDeclaration",
+                  "scope": 1139,
+                  "src": "28662:15:1",
+                  "stateVariable": false,
+                  "storageLocation": "default",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_uint256",
+                    "typeString": "uint256"
+                  },
+                  "typeName": {
+                    "id": 1112,
+                    "name": "uint256",
+                    "nodeType": "ElementaryTypeName",
+                    "src": "28662:7:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_uint256",
+                      "typeString": "uint256"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                }
+              ],
+              "src": "28646:32:1"
+            },
+            "returnParameters": {
+              "id": 1115,
+              "nodeType": "ParameterList",
+              "parameters": [],
+              "src": "28688:0:1"
+            },
+            "scope": 1302,
+            "src": "28632:364:1",
+            "stateMutability": "nonpayable",
+            "superFunction": 811,
+            "visibility": "internal"
+          },
+          {
+            "body": {
+              "id": 1151,
+              "nodeType": "Block",
+              "src": "29282:43:1",
+              "statements": [
+                {
+                  "expression": {
+                    "argumentTypes": null,
+                    "baseExpression": {
+                      "argumentTypes": null,
+                      "id": 1147,
+                      "name": "_ownedTokens",
+                      "nodeType": "Identifier",
+                      "overloadedDeclarations": [],
+                      "referencedDeclaration": 981,
+                      "src": "29299:12:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_mapping$_t_address_$_t_array$_t_uint256_$dyn_storage_$",
+                        "typeString": "mapping(address => uint256[] storage ref)"
+                      }
+                    },
+                    "id": 1149,
+                    "indexExpression": {
+                      "argumentTypes": null,
+                      "id": 1148,
+                      "name": "owner",
+                      "nodeType": "Identifier",
+                      "overloadedDeclarations": [],
+                      "referencedDeclaration": 1141,
+                      "src": "29312:5:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_address",
+                        "typeString": "address"
+                      }
+                    },
+                    "isConstant": false,
+                    "isLValue": true,
+                    "isPure": false,
+                    "lValueRequested": false,
+                    "nodeType": "IndexAccess",
+                    "src": "29299:19:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_array$_t_uint256_$dyn_storage",
+                      "typeString": "uint256[] storage ref"
+                    }
+                  },
+                  "functionReturnParameters": 1146,
+                  "id": 1150,
+                  "nodeType": "Return",
+                  "src": "29292:26:1"
+                }
+              ]
+            },
+            "documentation": "@dev Gets the list of token IDs of the requested owner.\n@param owner address owning the tokens\n@return uint256[] List of token IDs owned by the requested address",
+            "id": 1152,
+            "implemented": true,
+            "kind": "function",
+            "modifiers": [],
+            "name": "_tokensOfOwner",
+            "nodeType": "FunctionDefinition",
+            "parameters": {
+              "id": 1142,
+              "nodeType": "ParameterList",
+              "parameters": [
+                {
+                  "constant": false,
+                  "id": 1141,
+                  "name": "owner",
+                  "nodeType": "VariableDeclaration",
+                  "scope": 1152,
+                  "src": "29225:13:1",
+                  "stateVariable": false,
+                  "storageLocation": "default",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_address",
+                    "typeString": "address"
+                  },
+                  "typeName": {
+                    "id": 1140,
+                    "name": "address",
+                    "nodeType": "ElementaryTypeName",
+                    "src": "29225:7:1",
+                    "stateMutability": "nonpayable",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_address",
+                      "typeString": "address"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                }
+              ],
+              "src": "29224:15:1"
+            },
+            "returnParameters": {
+              "id": 1146,
+              "nodeType": "ParameterList",
+              "parameters": [
+                {
+                  "constant": false,
+                  "id": 1145,
+                  "name": "",
+                  "nodeType": "VariableDeclaration",
+                  "scope": 1152,
+                  "src": "29263:17:1",
+                  "stateVariable": false,
+                  "storageLocation": "storage",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_array$_t_uint256_$dyn_storage_ptr",
+                    "typeString": "uint256[]"
+                  },
+                  "typeName": {
+                    "baseType": {
+                      "id": 1143,
+                      "name": "uint256",
+                      "nodeType": "ElementaryTypeName",
+                      "src": "29263:7:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_uint256",
+                        "typeString": "uint256"
+                      }
+                    },
+                    "id": 1144,
+                    "length": null,
+                    "nodeType": "ArrayTypeName",
+                    "src": "29263:9:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_array$_t_uint256_$dyn_storage_ptr",
+                      "typeString": "uint256[]"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                }
+              ],
+              "src": "29262:19:1"
+            },
+            "scope": 1302,
+            "src": "29201:124:1",
+            "stateMutability": "view",
+            "superFunction": null,
+            "visibility": "internal"
+          },
+          {
+            "body": {
+              "id": 1175,
+              "nodeType": "Block",
+              "src": "29693:109:1",
+              "statements": [
+                {
+                  "expression": {
+                    "argumentTypes": null,
+                    "id": 1166,
+                    "isConstant": false,
+                    "isLValue": false,
+                    "isPure": false,
+                    "lValueRequested": false,
+                    "leftHandSide": {
+                      "argumentTypes": null,
+                      "baseExpression": {
+                        "argumentTypes": null,
+                        "id": 1159,
+                        "name": "_ownedTokensIndex",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 985,
+                        "src": "29703:17:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_mapping$_t_uint256_$_t_uint256_$",
+                          "typeString": "mapping(uint256 => uint256)"
+                        }
+                      },
+                      "id": 1161,
+                      "indexExpression": {
+                        "argumentTypes": null,
+                        "id": 1160,
+                        "name": "tokenId",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 1156,
+                        "src": "29721:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      },
+                      "isConstant": false,
+                      "isLValue": true,
+                      "isPure": false,
+                      "lValueRequested": true,
+                      "nodeType": "IndexAccess",
+                      "src": "29703:26:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_uint256",
+                        "typeString": "uint256"
+                      }
+                    },
+                    "nodeType": "Assignment",
+                    "operator": "=",
+                    "rightHandSide": {
+                      "argumentTypes": null,
+                      "expression": {
+                        "argumentTypes": null,
+                        "baseExpression": {
+                          "argumentTypes": null,
+                          "id": 1162,
+                          "name": "_ownedTokens",
+                          "nodeType": "Identifier",
+                          "overloadedDeclarations": [],
+                          "referencedDeclaration": 981,
+                          "src": "29732:12:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_mapping$_t_address_$_t_array$_t_uint256_$dyn_storage_$",
+                            "typeString": "mapping(address => uint256[] storage ref)"
+                          }
+                        },
+                        "id": 1164,
+                        "indexExpression": {
+                          "argumentTypes": null,
+                          "id": 1163,
+                          "name": "to",
+                          "nodeType": "Identifier",
+                          "overloadedDeclarations": [],
+                          "referencedDeclaration": 1154,
+                          "src": "29745:2:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_address",
+                            "typeString": "address"
+                          }
+                        },
+                        "isConstant": false,
+                        "isLValue": true,
+                        "isPure": false,
+                        "lValueRequested": false,
+                        "nodeType": "IndexAccess",
+                        "src": "29732:16:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_array$_t_uint256_$dyn_storage",
+                          "typeString": "uint256[] storage ref"
+                        }
+                      },
+                      "id": 1165,
+                      "isConstant": false,
+                      "isLValue": true,
+                      "isPure": false,
+                      "lValueRequested": false,
+                      "memberName": "length",
+                      "nodeType": "MemberAccess",
+                      "referencedDeclaration": null,
+                      "src": "29732:23:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_uint256",
+                        "typeString": "uint256"
+                      }
+                    },
+                    "src": "29703:52:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_uint256",
+                      "typeString": "uint256"
+                    }
+                  },
+                  "id": 1167,
+                  "nodeType": "ExpressionStatement",
+                  "src": "29703:52:1"
+                },
+                {
+                  "expression": {
+                    "argumentTypes": null,
+                    "arguments": [
+                      {
+                        "argumentTypes": null,
+                        "id": 1172,
+                        "name": "tokenId",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 1156,
+                        "src": "29787:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      }
+                    ],
+                    "expression": {
+                      "argumentTypes": [
+                        {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      ],
+                      "expression": {
+                        "argumentTypes": null,
+                        "baseExpression": {
+                          "argumentTypes": null,
+                          "id": 1168,
+                          "name": "_ownedTokens",
+                          "nodeType": "Identifier",
+                          "overloadedDeclarations": [],
+                          "referencedDeclaration": 981,
+                          "src": "29765:12:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_mapping$_t_address_$_t_array$_t_uint256_$dyn_storage_$",
+                            "typeString": "mapping(address => uint256[] storage ref)"
+                          }
+                        },
+                        "id": 1170,
+                        "indexExpression": {
+                          "argumentTypes": null,
+                          "id": 1169,
+                          "name": "to",
+                          "nodeType": "Identifier",
+                          "overloadedDeclarations": [],
+                          "referencedDeclaration": 1154,
+                          "src": "29778:2:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_address",
+                            "typeString": "address"
+                          }
+                        },
+                        "isConstant": false,
+                        "isLValue": true,
+                        "isPure": false,
+                        "lValueRequested": false,
+                        "nodeType": "IndexAccess",
+                        "src": "29765:16:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_array$_t_uint256_$dyn_storage",
+                          "typeString": "uint256[] storage ref"
+                        }
+                      },
+                      "id": 1171,
+                      "isConstant": false,
+                      "isLValue": false,
+                      "isPure": false,
+                      "lValueRequested": false,
+                      "memberName": "push",
+                      "nodeType": "MemberAccess",
+                      "referencedDeclaration": null,
+                      "src": "29765:21:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_function_arraypush_nonpayable$_t_uint256_$returns$_t_uint256_$",
+                        "typeString": "function (uint256) returns (uint256)"
+                      }
+                    },
+                    "id": 1173,
+                    "isConstant": false,
+                    "isLValue": false,
+                    "isPure": false,
+                    "kind": "functionCall",
+                    "lValueRequested": false,
+                    "names": [],
+                    "nodeType": "FunctionCall",
+                    "src": "29765:30:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_uint256",
+                      "typeString": "uint256"
+                    }
+                  },
+                  "id": 1174,
+                  "nodeType": "ExpressionStatement",
+                  "src": "29765:30:1"
+                }
+              ]
+            },
+            "documentation": "@dev Private function to add a token to this extension's ownership-tracking data structures.\n@param to address representing the new owner of the given token ID\n@param tokenId uint256 ID of the token to be added to the tokens list of the given address",
+            "id": 1176,
+            "implemented": true,
+            "kind": "function",
+            "modifiers": [],
+            "name": "_addTokenToOwnerEnumeration",
+            "nodeType": "FunctionDefinition",
+            "parameters": {
+              "id": 1157,
+              "nodeType": "ParameterList",
+              "parameters": [
+                {
+                  "constant": false,
+                  "id": 1154,
+                  "name": "to",
+                  "nodeType": "VariableDeclaration",
+                  "scope": 1176,
+                  "src": "29656:10:1",
+                  "stateVariable": false,
+                  "storageLocation": "default",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_address",
+                    "typeString": "address"
+                  },
+                  "typeName": {
+                    "id": 1153,
+                    "name": "address",
+                    "nodeType": "ElementaryTypeName",
+                    "src": "29656:7:1",
+                    "stateMutability": "nonpayable",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_address",
+                      "typeString": "address"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                },
+                {
+                  "constant": false,
+                  "id": 1156,
+                  "name": "tokenId",
+                  "nodeType": "VariableDeclaration",
+                  "scope": 1176,
+                  "src": "29668:15:1",
+                  "stateVariable": false,
+                  "storageLocation": "default",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_uint256",
+                    "typeString": "uint256"
+                  },
+                  "typeName": {
+                    "id": 1155,
+                    "name": "uint256",
+                    "nodeType": "ElementaryTypeName",
+                    "src": "29668:7:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_uint256",
+                      "typeString": "uint256"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                }
+              ],
+              "src": "29655:29:1"
+            },
+            "returnParameters": {
+              "id": 1158,
+              "nodeType": "ParameterList",
+              "parameters": [],
+              "src": "29693:0:1"
+            },
+            "scope": 1302,
+            "src": "29619:183:1",
+            "stateMutability": "nonpayable",
+            "superFunction": null,
+            "visibility": "private"
+          },
+          {
+            "body": {
+              "id": 1194,
+              "nodeType": "Block",
+              "src": "30063:95:1",
+              "statements": [
+                {
+                  "expression": {
+                    "argumentTypes": null,
+                    "id": 1186,
+                    "isConstant": false,
+                    "isLValue": false,
+                    "isPure": false,
+                    "lValueRequested": false,
+                    "leftHandSide": {
+                      "argumentTypes": null,
+                      "baseExpression": {
+                        "argumentTypes": null,
+                        "id": 1181,
+                        "name": "_allTokensIndex",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 992,
+                        "src": "30073:15:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_mapping$_t_uint256_$_t_uint256_$",
+                          "typeString": "mapping(uint256 => uint256)"
+                        }
+                      },
+                      "id": 1183,
+                      "indexExpression": {
+                        "argumentTypes": null,
+                        "id": 1182,
+                        "name": "tokenId",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 1178,
+                        "src": "30089:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      },
+                      "isConstant": false,
+                      "isLValue": true,
+                      "isPure": false,
+                      "lValueRequested": true,
+                      "nodeType": "IndexAccess",
+                      "src": "30073:24:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_uint256",
+                        "typeString": "uint256"
+                      }
+                    },
+                    "nodeType": "Assignment",
+                    "operator": "=",
+                    "rightHandSide": {
+                      "argumentTypes": null,
+                      "expression": {
+                        "argumentTypes": null,
+                        "id": 1184,
+                        "name": "_allTokens",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 988,
+                        "src": "30100:10:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_array$_t_uint256_$dyn_storage",
+                          "typeString": "uint256[] storage ref"
+                        }
+                      },
+                      "id": 1185,
+                      "isConstant": false,
+                      "isLValue": true,
+                      "isPure": false,
+                      "lValueRequested": false,
+                      "memberName": "length",
+                      "nodeType": "MemberAccess",
+                      "referencedDeclaration": null,
+                      "src": "30100:17:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_uint256",
+                        "typeString": "uint256"
+                      }
+                    },
+                    "src": "30073:44:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_uint256",
+                      "typeString": "uint256"
+                    }
+                  },
+                  "id": 1187,
+                  "nodeType": "ExpressionStatement",
+                  "src": "30073:44:1"
+                },
+                {
+                  "expression": {
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+                    "arguments": [
+                      {
+                        "argumentTypes": null,
+                        "id": 1191,
+                        "name": "tokenId",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 1178,
+                        "src": "30143:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      }
+                    ],
+                    "expression": {
+                      "argumentTypes": [
+                        {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      ],
+                      "expression": {
+                        "argumentTypes": null,
+                        "id": 1188,
+                        "name": "_allTokens",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 988,
+                        "src": "30127:10:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_array$_t_uint256_$dyn_storage",
+                          "typeString": "uint256[] storage ref"
+                        }
+                      },
+                      "id": 1190,
+                      "isConstant": false,
+                      "isLValue": false,
+                      "isPure": false,
+                      "lValueRequested": false,
+                      "memberName": "push",
+                      "nodeType": "MemberAccess",
+                      "referencedDeclaration": null,
+                      "src": "30127:15:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_function_arraypush_nonpayable$_t_uint256_$returns$_t_uint256_$",
+                        "typeString": "function (uint256) returns (uint256)"
+                      }
+                    },
+                    "id": 1192,
+                    "isConstant": false,
+                    "isLValue": false,
+                    "isPure": false,
+                    "kind": "functionCall",
+                    "lValueRequested": false,
+                    "names": [],
+                    "nodeType": "FunctionCall",
+                    "src": "30127:24:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_uint256",
+                      "typeString": "uint256"
+                    }
+                  },
+                  "id": 1193,
+                  "nodeType": "ExpressionStatement",
+                  "src": "30127:24:1"
+                }
+              ]
+            },
+            "documentation": "@dev Private function to add a token to this extension's token tracking data structures.\n@param tokenId uint256 ID of the token to be added to the tokens list",
+            "id": 1195,
+            "implemented": true,
+            "kind": "function",
+            "modifiers": [],
+            "name": "_addTokenToAllTokensEnumeration",
+            "nodeType": "FunctionDefinition",
+            "parameters": {
+              "id": 1179,
+              "nodeType": "ParameterList",
+              "parameters": [
+                {
+                  "constant": false,
+                  "id": 1178,
+                  "name": "tokenId",
+                  "nodeType": "VariableDeclaration",
+                  "scope": 1195,
+                  "src": "30038:15:1",
+                  "stateVariable": false,
+                  "storageLocation": "default",
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+                        },
+                        "value": "1"
+                      }
+                    ],
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+                            "src": "31060:12:1",
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+                              "typeIdentifier": "t_mapping$_t_address_$_t_array$_t_uint256_$dyn_storage_$",
+                              "typeString": "mapping(address => uint256[] storage ref)"
+                            }
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+                              "typeIdentifier": "t_address",
+                              "typeString": "address"
+                            }
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+                        "typeString": "function (uint256,uint256) pure returns (uint256)"
+                      }
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+                    "src": "31060:32:1",
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+                      "typeIdentifier": "t_uint256",
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+                    }
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+                },
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+                        "typeIdentifier": "t_uint256",
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+                      },
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+                        "name": "uint256",
+                        "nodeType": "ElementaryTypeName",
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+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
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+                        "typeIdentifier": "t_mapping$_t_uint256_$_t_uint256_$",
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+                      }
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+                        "typeString": "uint256"
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+                      "typeString": "uint256"
+                    }
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+                },
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+                      "src": "31253:10:1",
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+                        "typeIdentifier": "t_uint256",
+                        "typeString": "uint256"
+                      }
+                    },
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+                      "name": "lastTokenIndex",
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+                      "src": "31267:14:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_uint256",
+                        "typeString": "uint256"
+                      }
+                    },
+                    "src": "31253:28:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_bool",
+                      "typeString": "bool"
+                    }
+                  },
+                  "falseBody": null,
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+                  "src": "31249:323:1",
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+                    "statements": [
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+                        "assignments": [
+                          1222
+                        ],
+                        "declarations": [
+                          {
+                            "constant": false,
+                            "id": 1222,
+                            "name": "lastTokenId",
+                            "nodeType": "VariableDeclaration",
+                            "scope": 1243,
+                            "src": "31297:19:1",
+                            "stateVariable": false,
+                            "storageLocation": "default",
+                            "typeDescriptions": {
+                              "typeIdentifier": "t_uint256",
+                              "typeString": "uint256"
+                            },
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+                              "name": "uint256",
+                              "nodeType": "ElementaryTypeName",
+                              "src": "31297:7:1",
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+                                "typeIdentifier": "t_uint256",
+                                "typeString": "uint256"
+                              }
+                            },
+                            "value": null,
+                            "visibility": "internal"
+                          }
+                        ],
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+                          "baseExpression": {
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+                              "id": 1223,
+                              "name": "_ownedTokens",
+                              "nodeType": "Identifier",
+                              "overloadedDeclarations": [],
+                              "referencedDeclaration": 981,
+                              "src": "31319:12:1",
+                              "typeDescriptions": {
+                                "typeIdentifier": "t_mapping$_t_address_$_t_array$_t_uint256_$dyn_storage_$",
+                                "typeString": "mapping(address => uint256[] storage ref)"
+                              }
+                            },
+                            "id": 1225,
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+                              "name": "from",
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+                              "referencedDeclaration": 1197,
+                              "src": "31332:4:1",
+                              "typeDescriptions": {
+                                "typeIdentifier": "t_address",
+                                "typeString": "address"
+                              }
+                            },
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+                            "nodeType": "IndexAccess",
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+                              "typeIdentifier": "t_array$_t_uint256_$dyn_storage",
+                              "typeString": "uint256[] storage ref"
+                            }
+                          },
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+                            "argumentTypes": null,
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+                            "name": "lastTokenIndex",
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+                            "src": "31338:14:1",
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+                              "typeIdentifier": "t_uint256",
+                              "typeString": "uint256"
+                            }
+                          },
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+                            "typeIdentifier": "t_uint256",
+                            "typeString": "uint256"
+                          }
+                        },
+                        "nodeType": "VariableDeclarationStatement",
+                        "src": "31297:56:1"
+                      },
+                      {
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+                              "baseExpression": {
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+                                "name": "_ownedTokens",
+                                "nodeType": "Identifier",
+                                "overloadedDeclarations": [],
+                                "referencedDeclaration": 981,
+                                "src": "31368:12:1",
+                                "typeDescriptions": {
+                                  "typeIdentifier": "t_mapping$_t_address_$_t_array$_t_uint256_$dyn_storage_$",
+                                  "typeString": "mapping(address => uint256[] storage ref)"
+                                }
+                              },
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+                                "argumentTypes": null,
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+                                "name": "from",
+                                "nodeType": "Identifier",
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+                                "referencedDeclaration": 1197,
+                                "src": "31381:4:1",
+                                "typeDescriptions": {
+                                  "typeIdentifier": "t_address",
+                                  "typeString": "address"
+                                }
+                              },
+                              "isConstant": false,
+                              "isLValue": true,
+                              "isPure": false,
+                              "lValueRequested": false,
+                              "nodeType": "IndexAccess",
+                              "src": "31368:18:1",
+                              "typeDescriptions": {
+                                "typeIdentifier": "t_array$_t_uint256_$dyn_storage",
+                                "typeString": "uint256[] storage ref"
+                              }
+                            },
+                            "id": 1233,
+                            "indexExpression": {
+                              "argumentTypes": null,
+                              "id": 1231,
+                              "name": "tokenIndex",
+                              "nodeType": "Identifier",
+                              "overloadedDeclarations": [],
+                              "referencedDeclaration": 1213,
+                              "src": "31387:10:1",
+                              "typeDescriptions": {
+                                "typeIdentifier": "t_uint256",
+                                "typeString": "uint256"
+                              }
+                            },
+                            "isConstant": false,
+                            "isLValue": true,
+                            "isPure": false,
+                            "lValueRequested": true,
+                            "nodeType": "IndexAccess",
+                            "src": "31368:30:1",
+                            "typeDescriptions": {
+                              "typeIdentifier": "t_uint256",
+                              "typeString": "uint256"
+                            }
+                          },
+                          "nodeType": "Assignment",
+                          "operator": "=",
+                          "rightHandSide": {
+                            "argumentTypes": null,
+                            "id": 1234,
+                            "name": "lastTokenId",
+                            "nodeType": "Identifier",
+                            "overloadedDeclarations": [],
+                            "referencedDeclaration": 1222,
+                            "src": "31401:11:1",
+                            "typeDescriptions": {
+                              "typeIdentifier": "t_uint256",
+                              "typeString": "uint256"
+                            }
+                          },
+                          "src": "31368:44:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_uint256",
+                            "typeString": "uint256"
+                          }
+                        },
+                        "id": 1236,
+                        "nodeType": "ExpressionStatement",
+                        "src": "31368:44:1"
+                      },
+                      {
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+                          "id": 1241,
+                          "isConstant": false,
+                          "isLValue": false,
+                          "isPure": false,
+                          "lValueRequested": false,
+                          "leftHandSide": {
+                            "argumentTypes": null,
+                            "baseExpression": {
+                              "argumentTypes": null,
+                              "id": 1237,
+                              "name": "_ownedTokensIndex",
+                              "nodeType": "Identifier",
+                              "overloadedDeclarations": [],
+                              "referencedDeclaration": 985,
+                              "src": "31484:17:1",
+                              "typeDescriptions": {
+                                "typeIdentifier": "t_mapping$_t_uint256_$_t_uint256_$",
+                                "typeString": "mapping(uint256 => uint256)"
+                              }
+                            },
+                            "id": 1239,
+                            "indexExpression": {
+                              "argumentTypes": null,
+                              "id": 1238,
+                              "name": "lastTokenId",
+                              "nodeType": "Identifier",
+                              "overloadedDeclarations": [],
+                              "referencedDeclaration": 1222,
+                              "src": "31502:11:1",
+                              "typeDescriptions": {
+                                "typeIdentifier": "t_uint256",
+                                "typeString": "uint256"
+                              }
+                            },
+                            "isConstant": false,
+                            "isLValue": true,
+                            "isPure": false,
+                            "lValueRequested": true,
+                            "nodeType": "IndexAccess",
+                            "src": "31484:30:1",
+                            "typeDescriptions": {
+                              "typeIdentifier": "t_uint256",
+                              "typeString": "uint256"
+                            }
+                          },
+                          "nodeType": "Assignment",
+                          "operator": "=",
+                          "rightHandSide": {
+                            "argumentTypes": null,
+                            "id": 1240,
+                            "name": "tokenIndex",
+                            "nodeType": "Identifier",
+                            "overloadedDeclarations": [],
+                            "referencedDeclaration": 1213,
+                            "src": "31517:10:1",
+                            "typeDescriptions": {
+                              "typeIdentifier": "t_uint256",
+                              "typeString": "uint256"
+                            }
+                          },
+                          "src": "31484:43:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_uint256",
+                            "typeString": "uint256"
+                          }
+                        },
+                        "id": 1242,
+                        "nodeType": "ExpressionStatement",
+                        "src": "31484:43:1"
+                      }
+                    ]
+                  }
+                },
+                {
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+                    "id": 1249,
+                    "isConstant": false,
+                    "isLValue": false,
+                    "isPure": false,
+                    "lValueRequested": false,
+                    "nodeType": "UnaryOperation",
+                    "operator": "--",
+                    "prefix": false,
+                    "src": "31658:27:1",
+                    "subExpression": {
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+                      "expression": {
+                        "argumentTypes": null,
+                        "baseExpression": {
+                          "argumentTypes": null,
+                          "id": 1245,
+                          "name": "_ownedTokens",
+                          "nodeType": "Identifier",
+                          "overloadedDeclarations": [],
+                          "referencedDeclaration": 981,
+                          "src": "31658:12:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_mapping$_t_address_$_t_array$_t_uint256_$dyn_storage_$",
+                            "typeString": "mapping(address => uint256[] storage ref)"
+                          }
+                        },
+                        "id": 1247,
+                        "indexExpression": {
+                          "argumentTypes": null,
+                          "id": 1246,
+                          "name": "from",
+                          "nodeType": "Identifier",
+                          "overloadedDeclarations": [],
+                          "referencedDeclaration": 1197,
+                          "src": "31671:4:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_address",
+                            "typeString": "address"
+                          }
+                        },
+                        "isConstant": false,
+                        "isLValue": true,
+                        "isPure": false,
+                        "lValueRequested": false,
+                        "nodeType": "IndexAccess",
+                        "src": "31658:18:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_array$_t_uint256_$dyn_storage",
+                          "typeString": "uint256[] storage ref"
+                        }
+                      },
+                      "id": 1248,
+                      "isConstant": false,
+                      "isLValue": true,
+                      "isPure": false,
+                      "lValueRequested": true,
+                      "memberName": "length",
+                      "nodeType": "MemberAccess",
+                      "referencedDeclaration": null,
+                      "src": "31658:25:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_uint256",
+                        "typeString": "uint256"
+                      }
+                    },
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_uint256",
+                      "typeString": "uint256"
+                    }
+                  },
+                  "id": 1250,
+                  "nodeType": "ExpressionStatement",
+                  "src": "31658:27:1"
+                }
+              ]
+            },
+            "documentation": "@dev Private function to remove a token from this extension's ownership-tracking data structures. Note that\nwhile the token is not assigned a new owner, the _ownedTokensIndex mapping is _not_ updated: this allows for\ngas optimizations e.g. when performing a transfer operation (avoiding double writes).\nThis has O(1) time complexity, but alters the order of the _ownedTokens array.\n@param from address representing the previous owner of the given token ID\n@param tokenId uint256 ID of the token to be removed from the tokens list of the given address",
+            "id": 1252,
+            "implemented": true,
+            "kind": "function",
+            "modifiers": [],
+            "name": "_removeTokenFromOwnerEnumeration",
+            "nodeType": "FunctionDefinition",
+            "parameters": {
+              "id": 1200,
+              "nodeType": "ParameterList",
+              "parameters": [
+                {
+                  "constant": false,
+                  "id": 1197,
+                  "name": "from",
+                  "nodeType": "VariableDeclaration",
+                  "scope": 1252,
+                  "src": "30815:12:1",
+                  "stateVariable": false,
+                  "storageLocation": "default",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_address",
+                    "typeString": "address"
+                  },
+                  "typeName": {
+                    "id": 1196,
+                    "name": "address",
+                    "nodeType": "ElementaryTypeName",
+                    "src": "30815:7:1",
+                    "stateMutability": "nonpayable",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_address",
+                      "typeString": "address"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                },
+                {
+                  "constant": false,
+                  "id": 1199,
+                  "name": "tokenId",
+                  "nodeType": "VariableDeclaration",
+                  "scope": 1252,
+                  "src": "30829:15:1",
+                  "stateVariable": false,
+                  "storageLocation": "default",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_uint256",
+                    "typeString": "uint256"
+                  },
+                  "typeName": {
+                    "id": 1198,
+                    "name": "uint256",
+                    "nodeType": "ElementaryTypeName",
+                    "src": "30829:7:1",
+                    "typeDescriptions": {
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+            "documentation": "@dev Internal function to burn a specific token.\nReverts if the token does not exist.\nDeprecated, use _burn(uint256) instead.\n@param owner owner of the token to burn\n@param tokenId uint256 ID of the token being burned by the msg.sender",
+            "id": 1447,
+            "implemented": true,
+            "kind": "function",
+            "modifiers": [],
+            "name": "_burn",
+            "nodeType": "FunctionDefinition",
+            "parameters": {
+              "id": 1422,
+              "nodeType": "ParameterList",
+              "parameters": [
+                {
+                  "constant": false,
+                  "id": 1419,
+                  "name": "owner",
+                  "nodeType": "VariableDeclaration",
+                  "scope": 1447,
+                  "src": "36227:13:1",
+                  "stateVariable": false,
+                  "storageLocation": "default",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_address",
+                    "typeString": "address"
+                  },
+                  "typeName": {
+                    "id": 1418,
+                    "name": "address",
+                    "nodeType": "ElementaryTypeName",
+                    "src": "36227:7:1",
+                    "stateMutability": "nonpayable",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_address",
+                      "typeString": "address"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                },
+                {
+                  "constant": false,
+                  "id": 1421,
+                  "name": "tokenId",
+                  "nodeType": "VariableDeclaration",
+                  "scope": 1447,
+                  "src": "36242:15:1",
+                  "stateVariable": false,
+                  "storageLocation": "default",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_uint256",
+                    "typeString": "uint256"
+                  },
+                  "typeName": {
+                    "id": 1420,
+                    "name": "uint256",
+                    "nodeType": "ElementaryTypeName",
+                    "src": "36242:7:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_uint256",
+                      "typeString": "uint256"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                }
+              ],
+              "src": "36226:32:1"
+            },
+            "returnParameters": {
+              "id": 1423,
+              "nodeType": "ParameterList",
+              "parameters": [],
+              "src": "36268:0:1"
+            },
+            "scope": 1448,
+            "src": "36212:240:1",
+            "stateMutability": "nonpayable",
+            "superFunction": 811,
+            "visibility": "internal"
+          }
+        ],
+        "scope": 1469,
+        "src": "33817:2637:1"
+      },
+      {
+        "id": 1449,
+        "literals": [
+          "solidity",
+          "^",
+          "0.5",
+          ".0"
+        ],
+        "nodeType": "PragmaDirective",
+        "src": "36518:23:1"
+      },
+      {
+        "baseContracts": [
+          {
+            "arguments": null,
+            "baseName": {
+              "contractScope": null,
+              "id": 1450,
+              "name": "ERC721",
+              "nodeType": "UserDefinedTypeName",
+              "referencedDeclaration": 944,
+              "src": "36838:6:1",
+              "typeDescriptions": {
+                "typeIdentifier": "t_contract$_ERC721_$944",
+                "typeString": "contract ERC721"
+              }
+            },
+            "id": 1451,
+            "nodeType": "InheritanceSpecifier",
+            "src": "36838:6:1"
+          },
+          {
+            "arguments": null,
+            "baseName": {
+              "contractScope": null,
+              "id": 1452,
+              "name": "ERC721Enumerable",
+              "nodeType": "UserDefinedTypeName",
+              "referencedDeclaration": 1302,
+              "src": "36846:16:1",
+              "typeDescriptions": {
+                "typeIdentifier": "t_contract$_ERC721Enumerable_$1302",
+                "typeString": "contract ERC721Enumerable"
+              }
+            },
+            "id": 1453,
+            "nodeType": "InheritanceSpecifier",
+            "src": "36846:16:1"
+          },
+          {
+            "arguments": null,
+            "baseName": {
+              "contractScope": null,
+              "id": 1454,
+              "name": "ERC721Metadata",
+              "nodeType": "UserDefinedTypeName",
+              "referencedDeclaration": 1448,
+              "src": "36864:14:1",
+              "typeDescriptions": {
+                "typeIdentifier": "t_contract$_ERC721Metadata_$1448",
+                "typeString": "contract ERC721Metadata"
+              }
+            },
+            "id": 1455,
+            "nodeType": "InheritanceSpecifier",
+            "src": "36864:14:1"
+          }
+        ],
+        "contractDependencies": [
+          944,
+          969,
+          23,
+          124,
+          386,
+          1302,
+          1323,
+          1448
+        ],
+        "contractKind": "contract",
+        "documentation": "@title Full ERC721 Token\nThis implementation includes all the required and some optional functionality of the ERC721 standard\nMoreover, it includes approve all functionality using operator terminology\n@dev see https://eips.ethereum.org/EIPS/eip-721",
+        "fullyImplemented": true,
+        "id": 1468,
+        "linearizedBaseContracts": [
+          1468,
+          1448,
+          1323,
+          1302,
+          969,
+          944,
+          124,
+          386,
+          23
+        ],
+        "name": "ERC721Full",
+        "nodeType": "ContractDefinition",
+        "nodes": [
+          {
+            "body": {
+              "id": 1466,
+              "nodeType": "Block",
+              "src": "36976:64:1",
+              "statements": []
+            },
+            "documentation": null,
+            "id": 1467,
+            "implemented": true,
+            "kind": "constructor",
+            "modifiers": [
+              {
+                "arguments": [
+                  {
+                    "argumentTypes": null,
+                    "id": 1462,
+                    "name": "name",
+                    "nodeType": "Identifier",
+                    "overloadedDeclarations": [],
+                    "referencedDeclaration": 1457,
+                    "src": "36962:4:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_string_memory_ptr",
+                      "typeString": "string memory"
+                    }
+                  },
+                  {
+                    "argumentTypes": null,
+                    "id": 1463,
+                    "name": "symbol",
+                    "nodeType": "Identifier",
+                    "overloadedDeclarations": [],
+                    "referencedDeclaration": 1459,
+                    "src": "36968:6:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_string_memory_ptr",
+                      "typeString": "string memory"
+                    }
+                  }
+                ],
+                "id": 1464,
+                "modifierName": {
+                  "argumentTypes": null,
+                  "id": 1461,
+                  "name": "ERC721Metadata",
+                  "nodeType": "Identifier",
+                  "overloadedDeclarations": [],
+                  "referencedDeclaration": 1448,
+                  "src": "36947:14:1",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_type$_t_contract$_ERC721Metadata_$1448_$",
+                    "typeString": "type(contract ERC721Metadata)"
+                  }
+                },
+                "nodeType": "ModifierInvocation",
+                "src": "36947:28:1"
+              }
+            ],
+            "name": "",
+            "nodeType": "FunctionDefinition",
+            "parameters": {
+              "id": 1460,
+              "nodeType": "ParameterList",
+              "parameters": [
+                {
+                  "constant": false,
+                  "id": 1457,
+                  "name": "name",
+                  "nodeType": "VariableDeclaration",
+                  "scope": 1467,
+                  "src": "36898:18:1",
+                  "stateVariable": false,
+                  "storageLocation": "memory",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_string_memory_ptr",
+                    "typeString": "string"
+                  },
+                  "typeName": {
+                    "id": 1456,
+                    "name": "string",
+                    "nodeType": "ElementaryTypeName",
+                    "src": "36898:6:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_string_storage_ptr",
+                      "typeString": "string"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                },
+                {
+                  "constant": false,
+                  "id": 1459,
+                  "name": "symbol",
+                  "nodeType": "VariableDeclaration",
+                  "scope": 1467,
+                  "src": "36918:20:1",
+                  "stateVariable": false,
+                  "storageLocation": "memory",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_string_memory_ptr",
+                    "typeString": "string"
+                  },
+                  "typeName": {
+                    "id": 1458,
+                    "name": "string",
+                    "nodeType": "ElementaryTypeName",
+                    "src": "36918:6:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_string_storage_ptr",
+                      "typeString": "string"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                }
+              ],
+              "src": "36897:42:1"
+            },
+            "returnParameters": {
+              "id": 1465,
+              "nodeType": "ParameterList",
+              "parameters": [],
+              "src": "36976:0:1"
+            },
+            "scope": 1468,
+            "src": "36885:155:1",
+            "stateMutability": "nonpayable",
+            "superFunction": null,
+            "visibility": "public"
+          }
+        ],
+        "scope": 1469,
+        "src": "36815:227:1"
+      }
+    ],
+    "src": "61:36982:1"
+  },
+  "compiler": {
+    "name": "solc",
+    "version": "0.5.0+commit.1d4f565a.Emscripten.clang"
+  },
+  "networks": {},
+  "schemaVersion": "3.0.2",
+  "updatedAt": "2019-09-05T15:01:08.838Z",
+  "devdoc": {
+    "details": "See https://eips.ethereum.org/EIPS/eip-721",
+    "methods": {
+      "balanceOf(address)": {
+        "details": "Returns the number of NFTs in `owner`'s account."
+      },
+      "ownerOf(uint256)": {
+        "details": "Returns the owner of the NFT specified by `tokenId`."
+      },
+      "safeTransferFrom(address,address,uint256)": {
+        "details": "Transfers a specific NFT (`tokenId`) from one account (`from`) to another (`to`).     *      * Requirements: - `from`, `to` cannot be zero. - `tokenId` must be owned by `from`. - If the caller is not `from`, it must be have been allowed to move this NFT by either `approve` or `setApproveForAll`."
+      },
+      "supportsInterface(bytes4)": {
+        "details": "Returns true if this contract implements the interface defined by `interfaceId`. See the corresponding [EIP section](https://eips.ethereum.org/EIPS/eip-165#how-interfaces-are-identified) to learn more about how these ids are created.     * This function call must use less than 30 000 gas."
+      },
+      "transferFrom(address,address,uint256)": {
+        "details": "Transfers a specific NFT (`tokenId`) from one account (`from`) to another (`to`).     * Requirements: - If the caller is not `from`, it must be approved to move this NFT by either `approve` or `setApproveForAll`."
+      }
+    },
+    "title": "ERC-721 Non-Fungible Token Standard, optional enumeration extension"
+  },
+  "userdoc": {
+    "methods": {}
+  }
+}
\ No newline at end of file
diff --git a/src/abis/IERC721Metadata.json b/src/abis/IERC721Metadata.json
new file mode 100644
index 0000000..bcad8e7
--- /dev/null
+++ b/src/abis/IERC721Metadata.json
@@ -0,0 +1,37784 @@
+{
+  "contractName": "IERC721Metadata",
+  "abi": [
+    {
+      "constant": true,
+      "inputs": [
+        {
+          "name": "interfaceId",
+          "type": "bytes4"
+        }
+      ],
+      "name": "supportsInterface",
+      "outputs": [
+        {
+          "name": "",
+          "type": "bool"
+        }
+      ],
+      "payable": false,
+      "stateMutability": "view",
+      "type": "function"
+    },
+    {
+      "constant": true,
+      "inputs": [
+        {
+          "name": "tokenId",
+          "type": "uint256"
+        }
+      ],
+      "name": "getApproved",
+      "outputs": [
+        {
+          "name": "operator",
+          "type": "address"
+        }
+      ],
+      "payable": false,
+      "stateMutability": "view",
+      "type": "function"
+    },
+    {
+      "constant": false,
+      "inputs": [
+        {
+          "name": "to",
+          "type": "address"
+        },
+        {
+          "name": "tokenId",
+          "type": "uint256"
+        }
+      ],
+      "name": "approve",
+      "outputs": [],
+      "payable": false,
+      "stateMutability": "nonpayable",
+      "type": "function"
+    },
+    {
+      "constant": false,
+      "inputs": [
+        {
+          "name": "from",
+          "type": "address"
+        },
+        {
+          "name": "to",
+          "type": "address"
+        },
+        {
+          "name": "tokenId",
+          "type": "uint256"
+        }
+      ],
+      "name": "transferFrom",
+      "outputs": [],
+      "payable": false,
+      "stateMutability": "nonpayable",
+      "type": "function"
+    },
+    {
+      "constant": false,
+      "inputs": [
+        {
+          "name": "from",
+          "type": "address"
+        },
+        {
+          "name": "to",
+          "type": "address"
+        },
+        {
+          "name": "tokenId",
+          "type": "uint256"
+        }
+      ],
+      "name": "safeTransferFrom",
+      "outputs": [],
+      "payable": false,
+      "stateMutability": "nonpayable",
+      "type": "function"
+    },
+    {
+      "constant": true,
+      "inputs": [
+        {
+          "name": "tokenId",
+          "type": "uint256"
+        }
+      ],
+      "name": "ownerOf",
+      "outputs": [
+        {
+          "name": "owner",
+          "type": "address"
+        }
+      ],
+      "payable": false,
+      "stateMutability": "view",
+      "type": "function"
+    },
+    {
+      "constant": true,
+      "inputs": [
+        {
+          "name": "owner",
+          "type": "address"
+        }
+      ],
+      "name": "balanceOf",
+      "outputs": [
+        {
+          "name": "balance",
+          "type": "uint256"
+        }
+      ],
+      "payable": false,
+      "stateMutability": "view",
+      "type": "function"
+    },
+    {
+      "constant": false,
+      "inputs": [
+        {
+          "name": "operator",
+          "type": "address"
+        },
+        {
+          "name": "_approved",
+          "type": "bool"
+        }
+      ],
+      "name": "setApprovalForAll",
+      "outputs": [],
+      "payable": false,
+      "stateMutability": "nonpayable",
+      "type": "function"
+    },
+    {
+      "constant": false,
+      "inputs": [
+        {
+          "name": "from",
+          "type": "address"
+        },
+        {
+          "name": "to",
+          "type": "address"
+        },
+        {
+          "name": "tokenId",
+          "type": "uint256"
+        },
+        {
+          "name": "data",
+          "type": "bytes"
+        }
+      ],
+      "name": "safeTransferFrom",
+      "outputs": [],
+      "payable": false,
+      "stateMutability": "nonpayable",
+      "type": "function"
+    },
+    {
+      "constant": true,
+      "inputs": [
+        {
+          "name": "owner",
+          "type": "address"
+        },
+        {
+          "name": "operator",
+          "type": "address"
+        }
+      ],
+      "name": "isApprovedForAll",
+      "outputs": [
+        {
+          "name": "",
+          "type": "bool"
+        }
+      ],
+      "payable": false,
+      "stateMutability": "view",
+      "type": "function"
+    },
+    {
+      "anonymous": false,
+      "inputs": [
+        {
+          "indexed": true,
+          "name": "from",
+          "type": "address"
+        },
+        {
+          "indexed": true,
+          "name": "to",
+          "type": "address"
+        },
+        {
+          "indexed": true,
+          "name": "tokenId",
+          "type": "uint256"
+        }
+      ],
+      "name": "Transfer",
+      "type": "event"
+    },
+    {
+      "anonymous": false,
+      "inputs": [
+        {
+          "indexed": true,
+          "name": "owner",
+          "type": "address"
+        },
+        {
+          "indexed": true,
+          "name": "approved",
+          "type": "address"
+        },
+        {
+          "indexed": true,
+          "name": "tokenId",
+          "type": "uint256"
+        }
+      ],
+      "name": "Approval",
+      "type": "event"
+    },
+    {
+      "anonymous": false,
+      "inputs": [
+        {
+          "indexed": true,
+          "name": "owner",
+          "type": "address"
+        },
+        {
+          "indexed": true,
+          "name": "operator",
+          "type": "address"
+        },
+        {
+          "indexed": false,
+          "name": "approved",
+          "type": "bool"
+        }
+      ],
+      "name": "ApprovalForAll",
+      "type": "event"
+    },
+    {
+      "constant": true,
+      "inputs": [],
+      "name": "name",
+      "outputs": [
+        {
+          "name": "",
+          "type": "string"
+        }
+      ],
+      "payable": false,
+      "stateMutability": "view",
+      "type": "function"
+    },
+    {
+      "constant": true,
+      "inputs": [],
+      "name": "symbol",
+      "outputs": [
+        {
+          "name": "",
+          "type": "string"
+        }
+      ],
+      "payable": false,
+      "stateMutability": "view",
+      "type": "function"
+    },
+    {
+      "constant": true,
+      "inputs": [
+        {
+          "name": "tokenId",
+          "type": "uint256"
+        }
+      ],
+      "name": "tokenURI",
+      "outputs": [
+        {
+          "name": "",
+          "type": "string"
+        }
+      ],
+      "payable": false,
+      "stateMutability": "view",
+      "type": "function"
+    }
+  ],
+  "bytecode": "0x",
+  "deployedBytecode": "0x",
+  "sourceMap": "",
+  "deployedSourceMap": "",
+  "source": "\n// File: @openzeppelin/contracts/introspection/IERC165.sol\n\npragma solidity ^0.5.0;\n\n/**\n * @dev Interface of the ERC165 standard, as defined in the\n * [EIP](https://eips.ethereum.org/EIPS/eip-165).\n *\n * Implementers can declare support of contract interfaces, which can then be\n * queried by others (`ERC165Checker`).\n *\n * For an implementation, see `ERC165`.\n */\ninterface IERC165 {\n    /**\n     * @dev Returns true if this contract implements the interface defined by\n     * `interfaceId`. See the corresponding\n     * [EIP section](https://eips.ethereum.org/EIPS/eip-165#how-interfaces-are-identified)\n     * to learn more about how these ids are created.\n     *\n     * This function call must use less than 30 000 gas.\n     */\n    function supportsInterface(bytes4 interfaceId) external view returns (bool);\n}\n\n// File: @openzeppelin/contracts/token/ERC721/IERC721.sol\n\npragma solidity ^0.5.0;\n\n\n/**\n * @dev Required interface of an ERC721 compliant contract.\n */\ncontract IERC721 is IERC165 {\n    event Transfer(address indexed from, address indexed to, uint256 indexed tokenId);\n    event Approval(address indexed owner, address indexed approved, uint256 indexed tokenId);\n    event ApprovalForAll(address indexed owner, address indexed operator, bool approved);\n\n    /**\n     * @dev Returns the number of NFTs in `owner`'s account.\n     */\n    function balanceOf(address owner) public view returns (uint256 balance);\n\n    /**\n     * @dev Returns the owner of the NFT specified by `tokenId`.\n     */\n    function ownerOf(uint256 tokenId) public view returns (address owner);\n\n    /**\n     * @dev Transfers a specific NFT (`tokenId`) from one account (`from`) to\n     * another (`to`).\n     *\n     * \n     *\n     * Requirements:\n     * - `from`, `to` cannot be zero.\n     * - `tokenId` must be owned by `from`.\n     * - If the caller is not `from`, it must be have been allowed to move this\n     * NFT by either `approve` or `setApproveForAll`.\n     */\n    function safeTransferFrom(address from, address to, uint256 tokenId) public;\n    /**\n     * @dev Transfers a specific NFT (`tokenId`) from one account (`from`) to\n     * another (`to`).\n     *\n     * Requirements:\n     * - If the caller is not `from`, it must be approved to move this NFT by\n     * either `approve` or `setApproveForAll`.\n     */\n    function transferFrom(address from, address to, uint256 tokenId) public;\n    function approve(address to, uint256 tokenId) public;\n    function getApproved(uint256 tokenId) public view returns (address operator);\n\n    function setApprovalForAll(address operator, bool _approved) public;\n    function isApprovedForAll(address owner, address operator) public view returns (bool);\n\n\n    function safeTransferFrom(address from, address to, uint256 tokenId, bytes memory data) public;\n}\n\n// File: @openzeppelin/contracts/token/ERC721/IERC721Receiver.sol\n\npragma solidity ^0.5.0;\n\n/**\n * @title ERC721 token receiver interface\n * @dev Interface for any contract that wants to support safeTransfers\n * from ERC721 asset contracts.\n */\ncontract IERC721Receiver {\n    /**\n     * @notice Handle the receipt of an NFT\n     * @dev The ERC721 smart contract calls this function on the recipient\n     * after a `safeTransfer`. This function MUST return the function selector,\n     * otherwise the caller will revert the transaction. The selector to be\n     * returned can be obtained as `this.onERC721Received.selector`. This\n     * function MAY throw to revert and reject the transfer.\n     * Note: the ERC721 contract address is always the message sender.\n     * @param operator The address which called `safeTransferFrom` function\n     * @param from The address which previously owned the token\n     * @param tokenId The NFT identifier which is being transferred\n     * @param data Additional data with no specified format\n     * @return bytes4 `bytes4(keccak256(\"onERC721Received(address,address,uint256,bytes)\"))`\n     */\n    function onERC721Received(address operator, address from, uint256 tokenId, bytes memory data)\n    public returns (bytes4);\n}\n\n// File: @openzeppelin/contracts/math/SafeMath.sol\n\npragma solidity ^0.5.0;\n\n/**\n * @dev Wrappers over Solidity's arithmetic operations with added overflow\n * checks.\n *\n * Arithmetic operations in Solidity wrap on overflow. This can easily result\n * in bugs, because programmers usually assume that an overflow raises an\n * error, which is the standard behavior in high level programming languages.\n * `SafeMath` restores this intuition by reverting the transaction when an\n * operation overflows.\n *\n * Using this library instead of the unchecked operations eliminates an entire\n * class of bugs, so it's recommended to use it always.\n */\nlibrary SafeMath {\n    /**\n     * @dev Returns the addition of two unsigned integers, reverting on\n     * overflow.\n     *\n     * Counterpart to Solidity's `+` operator.\n     *\n     * Requirements:\n     * - Addition cannot overflow.\n     */\n    function add(uint256 a, uint256 b) internal pure returns (uint256) {\n        uint256 c = a + b;\n        require(c >= a, \"SafeMath: addition overflow\");\n\n        return c;\n    }\n\n    /**\n     * @dev Returns the subtraction of two unsigned integers, reverting on\n     * overflow (when the result is negative).\n     *\n     * Counterpart to Solidity's `-` operator.\n     *\n     * Requirements:\n     * - Subtraction cannot overflow.\n     */\n    function sub(uint256 a, uint256 b) internal pure returns (uint256) {\n        require(b <= a, \"SafeMath: subtraction overflow\");\n        uint256 c = a - b;\n\n        return c;\n    }\n\n    /**\n     * @dev Returns the multiplication of two unsigned integers, reverting on\n     * overflow.\n     *\n     * Counterpart to Solidity's `*` operator.\n     *\n     * Requirements:\n     * - Multiplication cannot overflow.\n     */\n    function mul(uint256 a, uint256 b) internal pure returns (uint256) {\n        // Gas optimization: this is cheaper than requiring 'a' not being zero, but the\n        // benefit is lost if 'b' is also tested.\n        // See: https://github.com/OpenZeppelin/openzeppelin-contracts/pull/522\n        if (a == 0) {\n            return 0;\n        }\n\n        uint256 c = a * b;\n        require(c / a == b, \"SafeMath: multiplication overflow\");\n\n        return c;\n    }\n\n    /**\n     * @dev Returns the integer division of two unsigned integers. Reverts on\n     * division by zero. The result is rounded towards zero.\n     *\n     * Counterpart to Solidity's `/` operator. Note: this function uses a\n     * `revert` opcode (which leaves remaining gas untouched) while Solidity\n     * uses an invalid opcode to revert (consuming all remaining gas).\n     *\n     * Requirements:\n     * - The divisor cannot be zero.\n     */\n    function div(uint256 a, uint256 b) internal pure returns (uint256) {\n        // Solidity only automatically asserts when dividing by 0\n        require(b > 0, \"SafeMath: division by zero\");\n        uint256 c = a / b;\n        // assert(a == b * c + a % b); // There is no case in which this doesn't hold\n\n        return c;\n    }\n\n    /**\n     * @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo),\n     * Reverts when dividing by zero.\n     *\n     * Counterpart to Solidity's `%` operator. This function uses a `revert`\n     * opcode (which leaves remaining gas untouched) while Solidity uses an\n     * invalid opcode to revert (consuming all remaining gas).\n     *\n     * Requirements:\n     * - The divisor cannot be zero.\n     */\n    function mod(uint256 a, uint256 b) internal pure returns (uint256) {\n        require(b != 0, \"SafeMath: modulo by zero\");\n        return a % b;\n    }\n}\n\n// File: @openzeppelin/contracts/utils/Address.sol\n\npragma solidity ^0.5.0;\n\n/**\n * @dev Collection of functions related to the address type,\n */\nlibrary Address {\n    /**\n     * @dev Returns true if `account` is a contract.\n     *\n     * This test is non-exhaustive, and there may be false-negatives: during the\n     * execution of a contract's constructor, its address will be reported as\n     * not containing a contract.\n     *\n     * > It is unsafe to assume that an address for which this function returns\n     * false is an externally-owned account (EOA) and not a contract.\n     */\n    function isContract(address account) internal view returns (bool) {\n        // This method relies in extcodesize, which returns 0 for contracts in\n        // construction, since the code is only stored at the end of the\n        // constructor execution.\n\n        uint256 size;\n        // solhint-disable-next-line no-inline-assembly\n        assembly { size := extcodesize(account) }\n        return size > 0;\n    }\n}\n\n// File: @openzeppelin/contracts/drafts/Counters.sol\n\npragma solidity ^0.5.0;\n\n\n/**\n * @title Counters\n * @author Matt Condon (@shrugs)\n * @dev Provides counters that can only be incremented or decremented by one. This can be used e.g. to track the number\n * of elements in a mapping, issuing ERC721 ids, or counting request ids.\n *\n * Include with `using Counters for Counters.Counter;`\n * Since it is not possible to overflow a 256 bit integer with increments of one, `increment` can skip the SafeMath\n * overflow check, thereby saving gas. This does assume however correct usage, in that the underlying `_value` is never\n * directly accessed.\n */\nlibrary Counters {\n    using SafeMath for uint256;\n\n    struct Counter {\n        // This variable should never be directly accessed by users of the library: interactions must be restricted to\n        // the library's function. As of Solidity v0.5.2, this cannot be enforced, though there is a proposal to add\n        // this feature: see https://github.com/ethereum/solidity/issues/4637\n        uint256 _value; // default: 0\n    }\n\n    function current(Counter storage counter) internal view returns (uint256) {\n        return counter._value;\n    }\n\n    function increment(Counter storage counter) internal {\n        counter._value += 1;\n    }\n\n    function decrement(Counter storage counter) internal {\n        counter._value = counter._value.sub(1);\n    }\n}\n\n// File: @openzeppelin/contracts/introspection/ERC165.sol\n\npragma solidity ^0.5.0;\n\n\n/**\n * @dev Implementation of the `IERC165` interface.\n *\n * Contracts may inherit from this and call `_registerInterface` to declare\n * their support of an interface.\n */\ncontract ERC165 is IERC165 {\n    /*\n     * bytes4(keccak256('supportsInterface(bytes4)')) == 0x01ffc9a7\n     */\n    bytes4 private constant _INTERFACE_ID_ERC165 = 0x01ffc9a7;\n\n    /**\n     * @dev Mapping of interface ids to whether or not it's supported.\n     */\n    mapping(bytes4 => bool) private _supportedInterfaces;\n\n    constructor () internal {\n        // Derived contracts need only register support for their own interfaces,\n        // we register support for ERC165 itself here\n        _registerInterface(_INTERFACE_ID_ERC165);\n    }\n\n    /**\n     * @dev See `IERC165.supportsInterface`.\n     *\n     * Time complexity O(1), guaranteed to always use less than 30 000 gas.\n     */\n    function supportsInterface(bytes4 interfaceId) external view returns (bool) {\n        return _supportedInterfaces[interfaceId];\n    }\n\n    /**\n     * @dev Registers the contract as an implementer of the interface defined by\n     * `interfaceId`. Support of the actual ERC165 interface is automatic and\n     * registering its interface id is not required.\n     *\n     * See `IERC165.supportsInterface`.\n     *\n     * Requirements:\n     *\n     * - `interfaceId` cannot be the ERC165 invalid interface (`0xffffffff`).\n     */\n    function _registerInterface(bytes4 interfaceId) internal {\n        require(interfaceId != 0xffffffff, \"ERC165: invalid interface id\");\n        _supportedInterfaces[interfaceId] = true;\n    }\n}\n\n// File: @openzeppelin/contracts/token/ERC721/ERC721.sol\n\npragma solidity ^0.5.0;\n\n\n\n\n\n\n\n/**\n * @title ERC721 Non-Fungible Token Standard basic implementation\n * @dev see https://eips.ethereum.org/EIPS/eip-721\n */\ncontract ERC721 is ERC165, IERC721 {\n    using SafeMath for uint256;\n    using Address for address;\n    using Counters for Counters.Counter;\n\n    // Equals to `bytes4(keccak256(\"onERC721Received(address,address,uint256,bytes)\"))`\n    // which can be also obtained as `IERC721Receiver(0).onERC721Received.selector`\n    bytes4 private constant _ERC721_RECEIVED = 0x150b7a02;\n\n    // Mapping from token ID to owner\n    mapping (uint256 => address) private _tokenOwner;\n\n    // Mapping from token ID to approved address\n    mapping (uint256 => address) private _tokenApprovals;\n\n    // Mapping from owner to number of owned token\n    mapping (address => Counters.Counter) private _ownedTokensCount;\n\n    // Mapping from owner to operator approvals\n    mapping (address => mapping (address => bool)) private _operatorApprovals;\n\n    /*\n     *     bytes4(keccak256('balanceOf(address)')) == 0x70a08231\n     *     bytes4(keccak256('ownerOf(uint256)')) == 0x6352211e\n     *     bytes4(keccak256('approve(address,uint256)')) == 0x095ea7b3\n     *     bytes4(keccak256('getApproved(uint256)')) == 0x081812fc\n     *     bytes4(keccak256('setApprovalForAll(address,bool)')) == 0xa22cb465\n     *     bytes4(keccak256('isApprovedForAll(address,address)')) == 0xe985e9c\n     *     bytes4(keccak256('transferFrom(address,address,uint256)')) == 0x23b872dd\n     *     bytes4(keccak256('safeTransferFrom(address,address,uint256)')) == 0x42842e0e\n     *     bytes4(keccak256('safeTransferFrom(address,address,uint256,bytes)')) == 0xb88d4fde\n     *\n     *     => 0x70a08231 ^ 0x6352211e ^ 0x095ea7b3 ^ 0x081812fc ^\n     *        0xa22cb465 ^ 0xe985e9c ^ 0x23b872dd ^ 0x42842e0e ^ 0xb88d4fde == 0x80ac58cd\n     */\n    bytes4 private constant _INTERFACE_ID_ERC721 = 0x80ac58cd;\n\n    constructor () public {\n        // register the supported interfaces to conform to ERC721 via ERC165\n        _registerInterface(_INTERFACE_ID_ERC721);\n    }\n\n    /**\n     * @dev Gets the balance of the specified address.\n     * @param owner address to query the balance of\n     * @return uint256 representing the amount owned by the passed address\n     */\n    function balanceOf(address owner) public view returns (uint256) {\n        require(owner != address(0), \"ERC721: balance query for the zero address\");\n\n        return _ownedTokensCount[owner].current();\n    }\n\n    /**\n     * @dev Gets the owner of the specified token ID.\n     * @param tokenId uint256 ID of the token to query the owner of\n     * @return address currently marked as the owner of the given token ID\n     */\n    function ownerOf(uint256 tokenId) public view returns (address) {\n        address owner = _tokenOwner[tokenId];\n        require(owner != address(0), \"ERC721: owner query for nonexistent token\");\n\n        return owner;\n    }\n\n    /**\n     * @dev Approves another address to transfer the given token ID\n     * The zero address indicates there is no approved address.\n     * There can only be one approved address per token at a given time.\n     * Can only be called by the token owner or an approved operator.\n     * @param to address to be approved for the given token ID\n     * @param tokenId uint256 ID of the token to be approved\n     */\n    function approve(address to, uint256 tokenId) public {\n        address owner = ownerOf(tokenId);\n        require(to != owner, \"ERC721: approval to current owner\");\n\n        require(msg.sender == owner || isApprovedForAll(owner, msg.sender),\n            \"ERC721: approve caller is not owner nor approved for all\"\n        );\n\n        _tokenApprovals[tokenId] = to;\n        emit Approval(owner, to, tokenId);\n    }\n\n    /**\n     * @dev Gets the approved address for a token ID, or zero if no address set\n     * Reverts if the token ID does not exist.\n     * @param tokenId uint256 ID of the token to query the approval of\n     * @return address currently approved for the given token ID\n     */\n    function getApproved(uint256 tokenId) public view returns (address) {\n        require(_exists(tokenId), \"ERC721: approved query for nonexistent token\");\n\n        return _tokenApprovals[tokenId];\n    }\n\n    /**\n     * @dev Sets or unsets the approval of a given operator\n     * An operator is allowed to transfer all tokens of the sender on their behalf.\n     * @param to operator address to set the approval\n     * @param approved representing the status of the approval to be set\n     */\n    function setApprovalForAll(address to, bool approved) public {\n        require(to != msg.sender, \"ERC721: approve to caller\");\n\n        _operatorApprovals[msg.sender][to] = approved;\n        emit ApprovalForAll(msg.sender, to, approved);\n    }\n\n    /**\n     * @dev Tells whether an operator is approved by a given owner.\n     * @param owner owner address which you want to query the approval of\n     * @param operator operator address which you want to query the approval of\n     * @return bool whether the given operator is approved by the given owner\n     */\n    function isApprovedForAll(address owner, address operator) public view returns (bool) {\n        return _operatorApprovals[owner][operator];\n    }\n\n    /**\n     * @dev Transfers the ownership of a given token ID to another address.\n     * Usage of this method is discouraged, use `safeTransferFrom` whenever possible.\n     * Requires the msg.sender to be the owner, approved, or operator.\n     * @param from current owner of the token\n     * @param to address to receive the ownership of the given token ID\n     * @param tokenId uint256 ID of the token to be transferred\n     */\n    function transferFrom(address from, address to, uint256 tokenId) public {\n        //solhint-disable-next-line max-line-length\n        require(_isApprovedOrOwner(msg.sender, tokenId), \"ERC721: transfer caller is not owner nor approved\");\n\n        _transferFrom(from, to, tokenId);\n    }\n\n    /**\n     * @dev Safely transfers the ownership of a given token ID to another address\n     * If the target address is a contract, it must implement `onERC721Received`,\n     * which is called upon a safe transfer, and return the magic value\n     * `bytes4(keccak256(\"onERC721Received(address,address,uint256,bytes)\"))`; otherwise,\n     * the transfer is reverted.\n     * Requires the msg.sender to be the owner, approved, or operator\n     * @param from current owner of the token\n     * @param to address to receive the ownership of the given token ID\n     * @param tokenId uint256 ID of the token to be transferred\n     */\n    function safeTransferFrom(address from, address to, uint256 tokenId) public {\n        safeTransferFrom(from, to, tokenId, \"\");\n    }\n\n    /**\n     * @dev Safely transfers the ownership of a given token ID to another address\n     * If the target address is a contract, it must implement `onERC721Received`,\n     * which is called upon a safe transfer, and return the magic value\n     * `bytes4(keccak256(\"onERC721Received(address,address,uint256,bytes)\"))`; otherwise,\n     * the transfer is reverted.\n     * Requires the msg.sender to be the owner, approved, or operator\n     * @param from current owner of the token\n     * @param to address to receive the ownership of the given token ID\n     * @param tokenId uint256 ID of the token to be transferred\n     * @param _data bytes data to send along with a safe transfer check\n     */\n    function safeTransferFrom(address from, address to, uint256 tokenId, bytes memory _data) public {\n        transferFrom(from, to, tokenId);\n        require(_checkOnERC721Received(from, to, tokenId, _data), \"ERC721: transfer to non ERC721Receiver implementer\");\n    }\n\n    /**\n     * @dev Returns whether the specified token exists.\n     * @param tokenId uint256 ID of the token to query the existence of\n     * @return bool whether the token exists\n     */\n    function _exists(uint256 tokenId) internal view returns (bool) {\n        address owner = _tokenOwner[tokenId];\n        return owner != address(0);\n    }\n\n    /**\n     * @dev Returns whether the given spender can transfer a given token ID.\n     * @param spender address of the spender to query\n     * @param tokenId uint256 ID of the token to be transferred\n     * @return bool whether the msg.sender is approved for the given token ID,\n     * is an operator of the owner, or is the owner of the token\n     */\n    function _isApprovedOrOwner(address spender, uint256 tokenId) internal view returns (bool) {\n        require(_exists(tokenId), \"ERC721: operator query for nonexistent token\");\n        address owner = ownerOf(tokenId);\n        return (spender == owner || getApproved(tokenId) == spender || isApprovedForAll(owner, spender));\n    }\n\n    /**\n     * @dev Internal function to mint a new token.\n     * Reverts if the given token ID already exists.\n     * @param to The address that will own the minted token\n     * @param tokenId uint256 ID of the token to be minted\n     */\n    function _mint(address to, uint256 tokenId) internal {\n        require(to != address(0), \"ERC721: mint to the zero address\");\n        require(!_exists(tokenId), \"ERC721: token already minted\");\n\n        _tokenOwner[tokenId] = to;\n        _ownedTokensCount[to].increment();\n\n        emit Transfer(address(0), to, tokenId);\n    }\n\n    /**\n     * @dev Internal function to burn a specific token.\n     * Reverts if the token does not exist.\n     * Deprecated, use _burn(uint256) instead.\n     * @param owner owner of the token to burn\n     * @param tokenId uint256 ID of the token being burned\n     */\n    function _burn(address owner, uint256 tokenId) internal {\n        require(ownerOf(tokenId) == owner, \"ERC721: burn of token that is not own\");\n\n        _clearApproval(tokenId);\n\n        _ownedTokensCount[owner].decrement();\n        _tokenOwner[tokenId] = address(0);\n\n        emit Transfer(owner, address(0), tokenId);\n    }\n\n    /**\n     * @dev Internal function to burn a specific token.\n     * Reverts if the token does not exist.\n     * @param tokenId uint256 ID of the token being burned\n     */\n    function _burn(uint256 tokenId) internal {\n        _burn(ownerOf(tokenId), tokenId);\n    }\n\n    /**\n     * @dev Internal function to transfer ownership of a given token ID to another address.\n     * As opposed to transferFrom, this imposes no restrictions on msg.sender.\n     * @param from current owner of the token\n     * @param to address to receive the ownership of the given token ID\n     * @param tokenId uint256 ID of the token to be transferred\n     */\n    function _transferFrom(address from, address to, uint256 tokenId) internal {\n        require(ownerOf(tokenId) == from, \"ERC721: transfer of token that is not own\");\n        require(to != address(0), \"ERC721: transfer to the zero address\");\n\n        _clearApproval(tokenId);\n\n        _ownedTokensCount[from].decrement();\n        _ownedTokensCount[to].increment();\n\n        _tokenOwner[tokenId] = to;\n\n        emit Transfer(from, to, tokenId);\n    }\n\n    /**\n     * @dev Internal function to invoke `onERC721Received` on a target address.\n     * The call is not executed if the target address is not a contract.\n     *\n     * This function is deprecated.\n     * @param from address representing the previous owner of the given token ID\n     * @param to target address that will receive the tokens\n     * @param tokenId uint256 ID of the token to be transferred\n     * @param _data bytes optional data to send along with the call\n     * @return bool whether the call correctly returned the expected magic value\n     */\n    function _checkOnERC721Received(address from, address to, uint256 tokenId, bytes memory _data)\n        internal returns (bool)\n    {\n        if (!to.isContract()) {\n            return true;\n        }\n\n        bytes4 retval = IERC721Receiver(to).onERC721Received(msg.sender, from, tokenId, _data);\n        return (retval == _ERC721_RECEIVED);\n    }\n\n    /**\n     * @dev Private function to clear current approval of a given token ID.\n     * @param tokenId uint256 ID of the token to be transferred\n     */\n    function _clearApproval(uint256 tokenId) private {\n        if (_tokenApprovals[tokenId] != address(0)) {\n            _tokenApprovals[tokenId] = address(0);\n        }\n    }\n}\n\n// File: @openzeppelin/contracts/token/ERC721/IERC721Enumerable.sol\n\npragma solidity ^0.5.0;\n\n\n/**\n * @title ERC-721 Non-Fungible Token Standard, optional enumeration extension\n * @dev See https://eips.ethereum.org/EIPS/eip-721\n */\ncontract IERC721Enumerable is IERC721 {\n    function totalSupply() public view returns (uint256);\n    function tokenOfOwnerByIndex(address owner, uint256 index) public view returns (uint256 tokenId);\n\n    function tokenByIndex(uint256 index) public view returns (uint256);\n}\n\n// File: @openzeppelin/contracts/token/ERC721/ERC721Enumerable.sol\n\npragma solidity ^0.5.0;\n\n\n\n\n/**\n * @title ERC-721 Non-Fungible Token with optional enumeration extension logic\n * @dev See https://eips.ethereum.org/EIPS/eip-721\n */\ncontract ERC721Enumerable is ERC165, ERC721, IERC721Enumerable {\n    // Mapping from owner to list of owned token IDs\n    mapping(address => uint256[]) private _ownedTokens;\n\n    // Mapping from token ID to index of the owner tokens list\n    mapping(uint256 => uint256) private _ownedTokensIndex;\n\n    // Array with all token ids, used for enumeration\n    uint256[] private _allTokens;\n\n    // Mapping from token id to position in the allTokens array\n    mapping(uint256 => uint256) private _allTokensIndex;\n\n    /*\n     *     bytes4(keccak256('totalSupply()')) == 0x18160ddd\n     *     bytes4(keccak256('tokenOfOwnerByIndex(address,uint256)')) == 0x2f745c59\n     *     bytes4(keccak256('tokenByIndex(uint256)')) == 0x4f6ccce7\n     *\n     *     => 0x18160ddd ^ 0x2f745c59 ^ 0x4f6ccce7 == 0x780e9d63\n     */\n    bytes4 private constant _INTERFACE_ID_ERC721_ENUMERABLE = 0x780e9d63;\n\n    /**\n     * @dev Constructor function.\n     */\n    constructor () public {\n        // register the supported interface to conform to ERC721Enumerable via ERC165\n        _registerInterface(_INTERFACE_ID_ERC721_ENUMERABLE);\n    }\n\n    /**\n     * @dev Gets the token ID at a given index of the tokens list of the requested owner.\n     * @param owner address owning the tokens list to be accessed\n     * @param index uint256 representing the index to be accessed of the requested tokens list\n     * @return uint256 token ID at the given index of the tokens list owned by the requested address\n     */\n    function tokenOfOwnerByIndex(address owner, uint256 index) public view returns (uint256) {\n        require(index < balanceOf(owner), \"ERC721Enumerable: owner index out of bounds\");\n        return _ownedTokens[owner][index];\n    }\n\n    /**\n     * @dev Gets the total amount of tokens stored by the contract.\n     * @return uint256 representing the total amount of tokens\n     */\n    function totalSupply() public view returns (uint256) {\n        return _allTokens.length;\n    }\n\n    /**\n     * @dev Gets the token ID at a given index of all the tokens in this contract\n     * Reverts if the index is greater or equal to the total number of tokens.\n     * @param index uint256 representing the index to be accessed of the tokens list\n     * @return uint256 token ID at the given index of the tokens list\n     */\n    function tokenByIndex(uint256 index) public view returns (uint256) {\n        require(index < totalSupply(), \"ERC721Enumerable: global index out of bounds\");\n        return _allTokens[index];\n    }\n\n    /**\n     * @dev Internal function to transfer ownership of a given token ID to another address.\n     * As opposed to transferFrom, this imposes no restrictions on msg.sender.\n     * @param from current owner of the token\n     * @param to address to receive the ownership of the given token ID\n     * @param tokenId uint256 ID of the token to be transferred\n     */\n    function _transferFrom(address from, address to, uint256 tokenId) internal {\n        super._transferFrom(from, to, tokenId);\n\n        _removeTokenFromOwnerEnumeration(from, tokenId);\n\n        _addTokenToOwnerEnumeration(to, tokenId);\n    }\n\n    /**\n     * @dev Internal function to mint a new token.\n     * Reverts if the given token ID already exists.\n     * @param to address the beneficiary that will own the minted token\n     * @param tokenId uint256 ID of the token to be minted\n     */\n    function _mint(address to, uint256 tokenId) internal {\n        super._mint(to, tokenId);\n\n        _addTokenToOwnerEnumeration(to, tokenId);\n\n        _addTokenToAllTokensEnumeration(tokenId);\n    }\n\n    /**\n     * @dev Internal function to burn a specific token.\n     * Reverts if the token does not exist.\n     * Deprecated, use _burn(uint256) instead.\n     * @param owner owner of the token to burn\n     * @param tokenId uint256 ID of the token being burned\n     */\n    function _burn(address owner, uint256 tokenId) internal {\n        super._burn(owner, tokenId);\n\n        _removeTokenFromOwnerEnumeration(owner, tokenId);\n        // Since tokenId will be deleted, we can clear its slot in _ownedTokensIndex to trigger a gas refund\n        _ownedTokensIndex[tokenId] = 0;\n\n        _removeTokenFromAllTokensEnumeration(tokenId);\n    }\n\n    /**\n     * @dev Gets the list of token IDs of the requested owner.\n     * @param owner address owning the tokens\n     * @return uint256[] List of token IDs owned by the requested address\n     */\n    function _tokensOfOwner(address owner) internal view returns (uint256[] storage) {\n        return _ownedTokens[owner];\n    }\n\n    /**\n     * @dev Private function to add a token to this extension's ownership-tracking data structures.\n     * @param to address representing the new owner of the given token ID\n     * @param tokenId uint256 ID of the token to be added to the tokens list of the given address\n     */\n    function _addTokenToOwnerEnumeration(address to, uint256 tokenId) private {\n        _ownedTokensIndex[tokenId] = _ownedTokens[to].length;\n        _ownedTokens[to].push(tokenId);\n    }\n\n    /**\n     * @dev Private function to add a token to this extension's token tracking data structures.\n     * @param tokenId uint256 ID of the token to be added to the tokens list\n     */\n    function _addTokenToAllTokensEnumeration(uint256 tokenId) private {\n        _allTokensIndex[tokenId] = _allTokens.length;\n        _allTokens.push(tokenId);\n    }\n\n    /**\n     * @dev Private function to remove a token from this extension's ownership-tracking data structures. Note that\n     * while the token is not assigned a new owner, the _ownedTokensIndex mapping is _not_ updated: this allows for\n     * gas optimizations e.g. when performing a transfer operation (avoiding double writes).\n     * This has O(1) time complexity, but alters the order of the _ownedTokens array.\n     * @param from address representing the previous owner of the given token ID\n     * @param tokenId uint256 ID of the token to be removed from the tokens list of the given address\n     */\n    function _removeTokenFromOwnerEnumeration(address from, uint256 tokenId) private {\n        // To prevent a gap in from's tokens array, we store the last token in the index of the token to delete, and\n        // then delete the last slot (swap and pop).\n\n        uint256 lastTokenIndex = _ownedTokens[from].length.sub(1);\n        uint256 tokenIndex = _ownedTokensIndex[tokenId];\n\n        // When the token to delete is the last token, the swap operation is unnecessary\n        if (tokenIndex != lastTokenIndex) {\n            uint256 lastTokenId = _ownedTokens[from][lastTokenIndex];\n\n            _ownedTokens[from][tokenIndex] = lastTokenId; // Move the last token to the slot of the to-delete token\n            _ownedTokensIndex[lastTokenId] = tokenIndex; // Update the moved token's index\n        }\n\n        // This also deletes the contents at the last position of the array\n        _ownedTokens[from].length--;\n\n        // Note that _ownedTokensIndex[tokenId] hasn't been cleared: it still points to the old slot (now occupied by\n        // lastTokenId, or just over the end of the array if the token was the last one).\n    }\n\n    /**\n     * @dev Private function to remove a token from this extension's token tracking data structures.\n     * This has O(1) time complexity, but alters the order of the _allTokens array.\n     * @param tokenId uint256 ID of the token to be removed from the tokens list\n     */\n    function _removeTokenFromAllTokensEnumeration(uint256 tokenId) private {\n        // To prevent a gap in the tokens array, we store the last token in the index of the token to delete, and\n        // then delete the last slot (swap and pop).\n\n        uint256 lastTokenIndex = _allTokens.length.sub(1);\n        uint256 tokenIndex = _allTokensIndex[tokenId];\n\n        // When the token to delete is the last token, the swap operation is unnecessary. However, since this occurs so\n        // rarely (when the last minted token is burnt) that we still do the swap here to avoid the gas cost of adding\n        // an 'if' statement (like in _removeTokenFromOwnerEnumeration)\n        uint256 lastTokenId = _allTokens[lastTokenIndex];\n\n        _allTokens[tokenIndex] = lastTokenId; // Move the last token to the slot of the to-delete token\n        _allTokensIndex[lastTokenId] = tokenIndex; // Update the moved token's index\n\n        // This also deletes the contents at the last position of the array\n        _allTokens.length--;\n        _allTokensIndex[tokenId] = 0;\n    }\n}\n\n// File: @openzeppelin/contracts/token/ERC721/IERC721Metadata.sol\n\npragma solidity ^0.5.0;\n\n\n/**\n * @title ERC-721 Non-Fungible Token Standard, optional metadata extension\n * @dev See https://eips.ethereum.org/EIPS/eip-721\n */\ncontract IERC721Metadata is IERC721 {\n    function name() external view returns (string memory);\n    function symbol() external view returns (string memory);\n    function tokenURI(uint256 tokenId) external view returns (string memory);\n}\n\n// File: @openzeppelin/contracts/token/ERC721/ERC721Metadata.sol\n\npragma solidity ^0.5.0;\n\n\n\n\ncontract ERC721Metadata is ERC165, ERC721, IERC721Metadata {\n    // Token name\n    string private _name;\n\n    // Token symbol\n    string private _symbol;\n\n    // Optional mapping for token URIs\n    mapping(uint256 => string) private _tokenURIs;\n\n    /*\n     *     bytes4(keccak256('name()')) == 0x06fdde03\n     *     bytes4(keccak256('symbol()')) == 0x95d89b41\n     *     bytes4(keccak256('tokenURI(uint256)')) == 0xc87b56dd\n     *\n     *     => 0x06fdde03 ^ 0x95d89b41 ^ 0xc87b56dd == 0x5b5e139f\n     */\n    bytes4 private constant _INTERFACE_ID_ERC721_METADATA = 0x5b5e139f;\n\n    /**\n     * @dev Constructor function\n     */\n    constructor (string memory name, string memory symbol) public {\n        _name = name;\n        _symbol = symbol;\n\n        // register the supported interfaces to conform to ERC721 via ERC165\n        _registerInterface(_INTERFACE_ID_ERC721_METADATA);\n    }\n\n    /**\n     * @dev Gets the token name.\n     * @return string representing the token name\n     */\n    function name() external view returns (string memory) {\n        return _name;\n    }\n\n    /**\n     * @dev Gets the token symbol.\n     * @return string representing the token symbol\n     */\n    function symbol() external view returns (string memory) {\n        return _symbol;\n    }\n\n    /**\n     * @dev Returns an URI for a given token ID.\n     * Throws if the token ID does not exist. May return an empty string.\n     * @param tokenId uint256 ID of the token to query\n     */\n    function tokenURI(uint256 tokenId) external view returns (string memory) {\n        require(_exists(tokenId), \"ERC721Metadata: URI query for nonexistent token\");\n        return _tokenURIs[tokenId];\n    }\n\n    /**\n     * @dev Internal function to set the token URI for a given token.\n     * Reverts if the token ID does not exist.\n     * @param tokenId uint256 ID of the token to set its URI\n     * @param uri string URI to assign\n     */\n    function _setTokenURI(uint256 tokenId, string memory uri) internal {\n        require(_exists(tokenId), \"ERC721Metadata: URI set of nonexistent token\");\n        _tokenURIs[tokenId] = uri;\n    }\n\n    /**\n     * @dev Internal function to burn a specific token.\n     * Reverts if the token does not exist.\n     * Deprecated, use _burn(uint256) instead.\n     * @param owner owner of the token to burn\n     * @param tokenId uint256 ID of the token being burned by the msg.sender\n     */\n    function _burn(address owner, uint256 tokenId) internal {\n        super._burn(owner, tokenId);\n\n        // Clear metadata (if any)\n        if (bytes(_tokenURIs[tokenId]).length != 0) {\n            delete _tokenURIs[tokenId];\n        }\n    }\n}\n\n// File: @openzeppelin/contracts/token/ERC721/ERC721Full.sol\n\npragma solidity ^0.5.0;\n\n\n\n\n/**\n * @title Full ERC721 Token\n * This implementation includes all the required and some optional functionality of the ERC721 standard\n * Moreover, it includes approve all functionality using operator terminology\n * @dev see https://eips.ethereum.org/EIPS/eip-721\n */\ncontract ERC721Full is ERC721, ERC721Enumerable, ERC721Metadata {\n    constructor (string memory name, string memory symbol) public ERC721Metadata(name, symbol) {\n        // solhint-disable-previous-line no-empty-blocks\n    }\n}\n",
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+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        }
+                      },
+                      {
+                        "argumentTypes": null,
+                        "id": 764,
+                        "name": "tokenId",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 727,
+                        "src": "21088:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      }
+                    ],
+                    "expression": {
+                      "argumentTypes": [
+                        {
+                          "typeIdentifier": "t_address_payable",
+                          "typeString": "address payable"
+                        },
+                        {
+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        },
+                        {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      ],
+                      "id": 759,
+                      "name": "Transfer",
+                      "nodeType": "Identifier",
+                      "overloadedDeclarations": [],
+                      "referencedDeclaration": 34,
+                      "src": "21063:8:1",
+                      "typeDescriptions": {
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+                    "isConstant": false,
+                    "isLValue": false,
+                    "isPure": false,
+                    "kind": "functionCall",
+                    "lValueRequested": false,
+                    "names": [],
+                    "nodeType": "FunctionCall",
+                    "src": "21063:33:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_tuple$__$",
+                      "typeString": "tuple()"
+                    }
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+                  "id": 766,
+                  "nodeType": "EmitStatement",
+                  "src": "21058:38:1"
+                }
+              ]
+            },
+            "documentation": "@dev Internal function to mint a new token.\nReverts if the given token ID already exists.\n@param to The address that will own the minted token\n@param tokenId uint256 ID of the token to be minted",
+            "id": 768,
+            "implemented": true,
+            "kind": "function",
+            "modifiers": [],
+            "name": "_mint",
+            "nodeType": "FunctionDefinition",
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+              "nodeType": "ParameterList",
+              "parameters": [
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+                  "id": 725,
+                  "name": "to",
+                  "nodeType": "VariableDeclaration",
+                  "scope": 768,
+                  "src": "20791:10:1",
+                  "stateVariable": false,
+                  "storageLocation": "default",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_address",
+                    "typeString": "address"
+                  },
+                  "typeName": {
+                    "id": 724,
+                    "name": "address",
+                    "nodeType": "ElementaryTypeName",
+                    "src": "20791:7:1",
+                    "stateMutability": "nonpayable",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_address",
+                      "typeString": "address"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                },
+                {
+                  "constant": false,
+                  "id": 727,
+                  "name": "tokenId",
+                  "nodeType": "VariableDeclaration",
+                  "scope": 768,
+                  "src": "20803:15:1",
+                  "stateVariable": false,
+                  "storageLocation": "default",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_uint256",
+                    "typeString": "uint256"
+                  },
+                  "typeName": {
+                    "id": 726,
+                    "name": "uint256",
+                    "nodeType": "ElementaryTypeName",
+                    "src": "20803:7:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_uint256",
+                      "typeString": "uint256"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                }
+              ],
+              "src": "20790:29:1"
+            },
+            "returnParameters": {
+              "id": 729,
+              "nodeType": "ParameterList",
+              "parameters": [],
+              "src": "20829:0:1"
+            },
+            "scope": 944,
+            "src": "20776:327:1",
+            "stateMutability": "nonpayable",
+            "superFunction": null,
+            "visibility": "internal"
+          },
+          {
+            "body": {
+              "id": 810,
+              "nodeType": "Block",
+              "src": "21434:268:1",
+              "statements": [
+                {
+                  "expression": {
+                    "argumentTypes": null,
+                    "arguments": [
+                      {
+                        "argumentTypes": null,
+                        "commonType": {
+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        },
+                        "id": 780,
+                        "isConstant": false,
+                        "isLValue": false,
+                        "isPure": false,
+                        "lValueRequested": false,
+                        "leftExpression": {
+                          "argumentTypes": null,
+                          "arguments": [
+                            {
+                              "argumentTypes": null,
+                              "id": 777,
+                              "name": "tokenId",
+                              "nodeType": "Identifier",
+                              "overloadedDeclarations": [],
+                              "referencedDeclaration": 772,
+                              "src": "21460:7:1",
+                              "typeDescriptions": {
+                                "typeIdentifier": "t_uint256",
+                                "typeString": "uint256"
+                              }
+                            }
+                          ],
+                          "expression": {
+                            "argumentTypes": [
+                              {
+                                "typeIdentifier": "t_uint256",
+                                "typeString": "uint256"
+                              }
+                            ],
+                            "id": 776,
+                            "name": "ownerOf",
+                            "nodeType": "Identifier",
+                            "overloadedDeclarations": [
+                              480
+                            ],
+                            "referencedDeclaration": 480,
+                            "src": "21452:7:1",
+                            "typeDescriptions": {
+                              "typeIdentifier": "t_function_internal_view$_t_uint256_$returns$_t_address_$",
+                              "typeString": "function (uint256) view returns (address)"
+                            }
+                          },
+                          "id": 778,
+                          "isConstant": false,
+                          "isLValue": false,
+                          "isPure": false,
+                          "kind": "functionCall",
+                          "lValueRequested": false,
+                          "names": [],
+                          "nodeType": "FunctionCall",
+                          "src": "21452:16:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_address",
+                            "typeString": "address"
+                          }
+                        },
+                        "nodeType": "BinaryOperation",
+                        "operator": "==",
+                        "rightExpression": {
+                          "argumentTypes": null,
+                          "id": 779,
+                          "name": "owner",
+                          "nodeType": "Identifier",
+                          "overloadedDeclarations": [],
+                          "referencedDeclaration": 770,
+                          "src": "21472:5:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_address",
+                            "typeString": "address"
+                          }
+                        },
+                        "src": "21452:25:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_bool",
+                          "typeString": "bool"
+                        }
+                      },
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+                        "argumentTypes": null,
+                        "hexValue": "4552433732313a206275726e206f6620746f6b656e2074686174206973206e6f74206f776e",
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+                        "isConstant": false,
+                        "isLValue": false,
+                        "isPure": true,
+                        "kind": "string",
+                        "lValueRequested": false,
+                        "nodeType": "Literal",
+                        "src": "21479:39:1",
+                        "subdenomination": null,
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_stringliteral_d9af5b321f427d3820b5fc07b432b1ddf1bb6411d5d926d9de9773fd616ab5ee",
+                          "typeString": "literal_string \"ERC721: burn of token that is not own\""
+                        },
+                        "value": "ERC721: burn of token that is not own"
+                      }
+                    ],
+                    "expression": {
+                      "argumentTypes": [
+                        {
+                          "typeIdentifier": "t_bool",
+                          "typeString": "bool"
+                        },
+                        {
+                          "typeIdentifier": "t_stringliteral_d9af5b321f427d3820b5fc07b432b1ddf1bb6411d5d926d9de9773fd616ab5ee",
+                          "typeString": "literal_string \"ERC721: burn of token that is not own\""
+                        }
+                      ],
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+                      "name": "require",
+                      "nodeType": "Identifier",
+                      "overloadedDeclarations": [
+                        1543,
+                        1544
+                      ],
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+                      "src": "21444:7:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_function_require_pure$_t_bool_$_t_string_memory_ptr_$returns$__$",
+                        "typeString": "function (bool,string memory) pure"
+                      }
+                    },
+                    "id": 782,
+                    "isConstant": false,
+                    "isLValue": false,
+                    "isPure": false,
+                    "kind": "functionCall",
+                    "lValueRequested": false,
+                    "names": [],
+                    "nodeType": "FunctionCall",
+                    "src": "21444:75:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_tuple$__$",
+                      "typeString": "tuple()"
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+                  },
+                  "id": 783,
+                  "nodeType": "ExpressionStatement",
+                  "src": "21444:75:1"
+                },
+                {
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+                    "argumentTypes": null,
+                    "arguments": [
+                      {
+                        "argumentTypes": null,
+                        "id": 785,
+                        "name": "tokenId",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 772,
+                        "src": "21545:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      }
+                    ],
+                    "expression": {
+                      "argumentTypes": [
+                        {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      ],
+                      "id": 784,
+                      "name": "_clearApproval",
+                      "nodeType": "Identifier",
+                      "overloadedDeclarations": [],
+                      "referencedDeclaration": 943,
+                      "src": "21530:14:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_function_internal_nonpayable$_t_uint256_$returns$__$",
+                        "typeString": "function (uint256)"
+                      }
+                    },
+                    "id": 786,
+                    "isConstant": false,
+                    "isLValue": false,
+                    "isPure": false,
+                    "kind": "functionCall",
+                    "lValueRequested": false,
+                    "names": [],
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+                    "src": "21530:23:1",
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+                      "typeString": "tuple()"
+                    }
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+                  "nodeType": "ExpressionStatement",
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+                },
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+                      "expression": {
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+                        "baseExpression": {
+                          "argumentTypes": null,
+                          "id": 788,
+                          "name": "_ownedTokensCount",
+                          "nodeType": "Identifier",
+                          "overloadedDeclarations": [],
+                          "referencedDeclaration": 415,
+                          "src": "21564:17:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_mapping$_t_address_$_t_struct$_Counter_$296_storage_$",
+                            "typeString": "mapping(address => struct Counters.Counter storage ref)"
+                          }
+                        },
+                        "id": 790,
+                        "indexExpression": {
+                          "argumentTypes": null,
+                          "id": 789,
+                          "name": "owner",
+                          "nodeType": "Identifier",
+                          "overloadedDeclarations": [],
+                          "referencedDeclaration": 770,
+                          "src": "21582:5:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_address",
+                            "typeString": "address"
+                          }
+                        },
+                        "isConstant": false,
+                        "isLValue": true,
+                        "isPure": false,
+                        "lValueRequested": false,
+                        "nodeType": "IndexAccess",
+                        "src": "21564:24:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_struct$_Counter_$296_storage",
+                          "typeString": "struct Counters.Counter storage ref"
+                        }
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+                      "id": 791,
+                      "isConstant": false,
+                      "isLValue": true,
+                      "isPure": false,
+                      "lValueRequested": false,
+                      "memberName": "decrement",
+                      "nodeType": "MemberAccess",
+                      "referencedDeclaration": 335,
+                      "src": "21564:34:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_function_internal_nonpayable$_t_struct$_Counter_$296_storage_ptr_$returns$__$bound_to$_t_struct$_Counter_$296_storage_ptr_$",
+                        "typeString": "function (struct Counters.Counter storage pointer)"
+                      }
+                    },
+                    "id": 792,
+                    "isConstant": false,
+                    "isLValue": false,
+                    "isPure": false,
+                    "kind": "functionCall",
+                    "lValueRequested": false,
+                    "names": [],
+                    "nodeType": "FunctionCall",
+                    "src": "21564:36:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_tuple$__$",
+                      "typeString": "tuple()"
+                    }
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+                  "id": 793,
+                  "nodeType": "ExpressionStatement",
+                  "src": "21564:36:1"
+                },
+                {
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+                    "id": 800,
+                    "isConstant": false,
+                    "isLValue": false,
+                    "isPure": false,
+                    "lValueRequested": false,
+                    "leftHandSide": {
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+                      "baseExpression": {
+                        "argumentTypes": null,
+                        "id": 794,
+                        "name": "_tokenOwner",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 407,
+                        "src": "21610:11:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_mapping$_t_uint256_$_t_address_$",
+                          "typeString": "mapping(uint256 => address)"
+                        }
+                      },
+                      "id": 796,
+                      "indexExpression": {
+                        "argumentTypes": null,
+                        "id": 795,
+                        "name": "tokenId",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 772,
+                        "src": "21622:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      },
+                      "isConstant": false,
+                      "isLValue": true,
+                      "isPure": false,
+                      "lValueRequested": true,
+                      "nodeType": "IndexAccess",
+                      "src": "21610:20:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_address",
+                        "typeString": "address"
+                      }
+                    },
+                    "nodeType": "Assignment",
+                    "operator": "=",
+                    "rightHandSide": {
+                      "argumentTypes": null,
+                      "arguments": [
+                        {
+                          "argumentTypes": null,
+                          "hexValue": "30",
+                          "id": 798,
+                          "isConstant": false,
+                          "isLValue": false,
+                          "isPure": true,
+                          "kind": "number",
+                          "lValueRequested": false,
+                          "nodeType": "Literal",
+                          "src": "21641:1:1",
+                          "subdenomination": null,
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_rational_0_by_1",
+                            "typeString": "int_const 0"
+                          },
+                          "value": "0"
+                        }
+                      ],
+                      "expression": {
+                        "argumentTypes": [
+                          {
+                            "typeIdentifier": "t_rational_0_by_1",
+                            "typeString": "int_const 0"
+                          }
+                        ],
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+                        "isConstant": false,
+                        "isLValue": false,
+                        "isPure": true,
+                        "lValueRequested": false,
+                        "nodeType": "ElementaryTypeNameExpression",
+                        "src": "21633:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_type$_t_address_$",
+                          "typeString": "type(address)"
+                        },
+                        "typeName": "address"
+                      },
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+                      "isConstant": false,
+                      "isLValue": false,
+                      "isPure": true,
+                      "kind": "typeConversion",
+                      "lValueRequested": false,
+                      "names": [],
+                      "nodeType": "FunctionCall",
+                      "src": "21633:10:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_address_payable",
+                        "typeString": "address payable"
+                      }
+                    },
+                    "src": "21610:33:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_address",
+                      "typeString": "address"
+                    }
+                  },
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+                  "nodeType": "ExpressionStatement",
+                  "src": "21610:33:1"
+                },
+                {
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+                    "arguments": [
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+                        "argumentTypes": null,
+                        "id": 803,
+                        "name": "owner",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 770,
+                        "src": "21668:5:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        }
+                      },
+                      {
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+                        "arguments": [
+                          {
+                            "argumentTypes": null,
+                            "hexValue": "30",
+                            "id": 805,
+                            "isConstant": false,
+                            "isLValue": false,
+                            "isPure": true,
+                            "kind": "number",
+                            "lValueRequested": false,
+                            "nodeType": "Literal",
+                            "src": "21683:1:1",
+                            "subdenomination": null,
+                            "typeDescriptions": {
+                              "typeIdentifier": "t_rational_0_by_1",
+                              "typeString": "int_const 0"
+                            },
+                            "value": "0"
+                          }
+                        ],
+                        "expression": {
+                          "argumentTypes": [
+                            {
+                              "typeIdentifier": "t_rational_0_by_1",
+                              "typeString": "int_const 0"
+                            }
+                          ],
+                          "id": 804,
+                          "isConstant": false,
+                          "isLValue": false,
+                          "isPure": true,
+                          "lValueRequested": false,
+                          "nodeType": "ElementaryTypeNameExpression",
+                          "src": "21675:7:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_type$_t_address_$",
+                            "typeString": "type(address)"
+                          },
+                          "typeName": "address"
+                        },
+                        "id": 806,
+                        "isConstant": false,
+                        "isLValue": false,
+                        "isPure": true,
+                        "kind": "typeConversion",
+                        "lValueRequested": false,
+                        "names": [],
+                        "nodeType": "FunctionCall",
+                        "src": "21675:10:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_address_payable",
+                          "typeString": "address payable"
+                        }
+                      },
+                      {
+                        "argumentTypes": null,
+                        "id": 807,
+                        "name": "tokenId",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 772,
+                        "src": "21687:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      }
+                    ],
+                    "expression": {
+                      "argumentTypes": [
+                        {
+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        },
+                        {
+                          "typeIdentifier": "t_address_payable",
+                          "typeString": "address payable"
+                        },
+                        {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      ],
+                      "id": 802,
+                      "name": "Transfer",
+                      "nodeType": "Identifier",
+                      "overloadedDeclarations": [],
+                      "referencedDeclaration": 34,
+                      "src": "21659:8:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_function_event_nonpayable$_t_address_$_t_address_$_t_uint256_$returns$__$",
+                        "typeString": "function (address,address,uint256)"
+                      }
+                    },
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+                    "isConstant": false,
+                    "isLValue": false,
+                    "isPure": false,
+                    "kind": "functionCall",
+                    "lValueRequested": false,
+                    "names": [],
+                    "nodeType": "FunctionCall",
+                    "src": "21659:36:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_tuple$__$",
+                      "typeString": "tuple()"
+                    }
+                  },
+                  "id": 809,
+                  "nodeType": "EmitStatement",
+                  "src": "21654:41:1"
+                }
+              ]
+            },
+            "documentation": "@dev Internal function to burn a specific token.\nReverts if the token does not exist.\nDeprecated, use _burn(uint256) instead.\n@param owner owner of the token to burn\n@param tokenId uint256 ID of the token being burned",
+            "id": 811,
+            "implemented": true,
+            "kind": "function",
+            "modifiers": [],
+            "name": "_burn",
+            "nodeType": "FunctionDefinition",
+            "parameters": {
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+              "nodeType": "ParameterList",
+              "parameters": [
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+                  "id": 770,
+                  "name": "owner",
+                  "nodeType": "VariableDeclaration",
+                  "scope": 811,
+                  "src": "21393:13:1",
+                  "stateVariable": false,
+                  "storageLocation": "default",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_address",
+                    "typeString": "address"
+                  },
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+                    "id": 769,
+                    "name": "address",
+                    "nodeType": "ElementaryTypeName",
+                    "src": "21393:7:1",
+                    "stateMutability": "nonpayable",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_address",
+                      "typeString": "address"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                },
+                {
+                  "constant": false,
+                  "id": 772,
+                  "name": "tokenId",
+                  "nodeType": "VariableDeclaration",
+                  "scope": 811,
+                  "src": "21408:15:1",
+                  "stateVariable": false,
+                  "storageLocation": "default",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_uint256",
+                    "typeString": "uint256"
+                  },
+                  "typeName": {
+                    "id": 771,
+                    "name": "uint256",
+                    "nodeType": "ElementaryTypeName",
+                    "src": "21408:7:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_uint256",
+                      "typeString": "uint256"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                }
+              ],
+              "src": "21392:32:1"
+            },
+            "returnParameters": {
+              "id": 774,
+              "nodeType": "ParameterList",
+              "parameters": [],
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+                          "typeString": "address"
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+                          "typeString": "uint256"
+                        }
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+                        {
+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        },
+                        {
+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        },
+                        {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
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+                          "name": "msg",
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+                          "src": "23630:3:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_magic_message",
+                            "typeString": "msg"
+                          }
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+                        "isPure": false,
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+                        "src": "23630:10:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_address_payable",
+                          "typeString": "address payable"
+                        }
+                      },
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+                        "name": "from",
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+                        "typeDescriptions": {
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+                          "typeString": "address"
+                        }
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+                        "name": "tokenId",
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+                        "src": "23648:7:1",
+                        "typeDescriptions": {
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+                        }
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+                          "typeIdentifier": "t_bytes_memory_ptr",
+                          "typeString": "bytes memory"
+                        }
+                      }
+                    ],
+                    "expression": {
+                      "argumentTypes": [
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+                          "typeIdentifier": "t_address_payable",
+                          "typeString": "address payable"
+                        },
+                        {
+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        },
+                        {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        },
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+                              "typeString": "address"
+                            }
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+                        ],
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+                              "typeIdentifier": "t_address",
+                              "typeString": "address"
+                            }
+                          ],
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+                          "name": "IERC721Receiver",
+                          "nodeType": "Identifier",
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+                          "referencedDeclaration": 139,
+                          "src": "23593:15:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_type$_t_contract$_IERC721Receiver_$139_$",
+                            "typeString": "type(contract IERC721Receiver)"
+                          }
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+                        "kind": "typeConversion",
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+                          "typeIdentifier": "t_contract$_IERC721Receiver_$139",
+                          "typeString": "contract IERC721Receiver"
+                        }
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+                      }
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+                    }
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+                        "commonType": {
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+                          "typeString": "bytes4"
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+                          "src": "23681:6:1",
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+                            "typeIdentifier": "t_bytes4",
+                            "typeString": "bytes4"
+                          }
+                        },
+                        "nodeType": "BinaryOperation",
+                        "operator": "==",
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+                          "id": 915,
+                          "name": "_ERC721_RECEIVED",
+                          "nodeType": "Identifier",
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+                          "referencedDeclaration": 403,
+                          "src": "23691:16:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_bytes4",
+                            "typeString": "bytes4"
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+                          "typeString": "bool"
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+                  "nodeType": "Return",
+                  "src": "23673:35:1"
+                }
+              ]
+            },
+            "documentation": "@dev Internal function to invoke `onERC721Received` on a target address.\nThe call is not executed if the target address is not a contract.\n     * This function is deprecated.\n@param from address representing the previous owner of the given token ID\n@param to target address that will receive the tokens\n@param tokenId uint256 ID of the token to be transferred\n@param _data bytes optional data to send along with the call\n@return bool whether the call correctly returned the expected magic value",
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+                    "src": "23426:7:1",
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+                  "src": "23443:18:1",
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+                  "storageLocation": "memory",
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+                          "typeString": "bool"
+                        },
+                        {
+                          "typeIdentifier": "t_stringliteral_d269a4e9f5820dcdb69ea21f528512eb9b927c8d846d48aa51c9219f461d4dcc",
+                          "typeString": "literal_string \"ERC721Enumerable: global index out of bounds\""
+                        }
+                      ],
+                      "id": 1044,
+                      "name": "require",
+                      "nodeType": "Identifier",
+                      "overloadedDeclarations": [
+                        1543,
+                        1544
+                      ],
+                      "referencedDeclaration": 1544,
+                      "src": "27171:7:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_function_require_pure$_t_bool_$_t_string_memory_ptr_$returns$__$",
+                        "typeString": "function (bool,string memory) pure"
+                      }
+                    },
+                    "id": 1050,
+                    "isConstant": false,
+                    "isLValue": false,
+                    "isPure": false,
+                    "kind": "functionCall",
+                    "lValueRequested": false,
+                    "names": [],
+                    "nodeType": "FunctionCall",
+                    "src": "27171:78:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_tuple$__$",
+                      "typeString": "tuple()"
+                    }
+                  },
+                  "id": 1051,
+                  "nodeType": "ExpressionStatement",
+                  "src": "27171:78:1"
+                },
+                {
+                  "expression": {
+                    "argumentTypes": null,
+                    "baseExpression": {
+                      "argumentTypes": null,
+                      "id": 1052,
+                      "name": "_allTokens",
+                      "nodeType": "Identifier",
+                      "overloadedDeclarations": [],
+                      "referencedDeclaration": 988,
+                      "src": "27266:10:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_array$_t_uint256_$dyn_storage",
+                        "typeString": "uint256[] storage ref"
+                      }
+                    },
+                    "id": 1054,
+                    "indexExpression": {
+                      "argumentTypes": null,
+                      "id": 1053,
+                      "name": "index",
+                      "nodeType": "Identifier",
+                      "overloadedDeclarations": [],
+                      "referencedDeclaration": 1039,
+                      "src": "27277:5:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_uint256",
+                        "typeString": "uint256"
+                      }
+                    },
+                    "isConstant": false,
+                    "isLValue": true,
+                    "isPure": false,
+                    "lValueRequested": false,
+                    "nodeType": "IndexAccess",
+                    "src": "27266:17:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_uint256",
+                      "typeString": "uint256"
+                    }
+                  },
+                  "functionReturnParameters": 1043,
+                  "id": 1055,
+                  "nodeType": "Return",
+                  "src": "27259:24:1"
+                }
+              ]
+            },
+            "documentation": "@dev Gets the token ID at a given index of all the tokens in this contract\nReverts if the index is greater or equal to the total number of tokens.\n@param index uint256 representing the index to be accessed of the tokens list\n@return uint256 token ID at the given index of the tokens list",
+            "id": 1057,
+            "implemented": true,
+            "kind": "function",
+            "modifiers": [],
+            "name": "tokenByIndex",
+            "nodeType": "FunctionDefinition",
+            "parameters": {
+              "id": 1040,
+              "nodeType": "ParameterList",
+              "parameters": [
+                {
+                  "constant": false,
+                  "id": 1039,
+                  "name": "index",
+                  "nodeType": "VariableDeclaration",
+                  "scope": 1057,
+                  "src": "27116:13:1",
+                  "stateVariable": false,
+                  "storageLocation": "default",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_uint256",
+                    "typeString": "uint256"
+                  },
+                  "typeName": {
+                    "id": 1038,
+                    "name": "uint256",
+                    "nodeType": "ElementaryTypeName",
+                    "src": "27116:7:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_uint256",
+                      "typeString": "uint256"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                }
+              ],
+              "src": "27115:15:1"
+            },
+            "returnParameters": {
+              "id": 1043,
+              "nodeType": "ParameterList",
+              "parameters": [
+                {
+                  "constant": false,
+                  "id": 1042,
+                  "name": "",
+                  "nodeType": "VariableDeclaration",
+                  "scope": 1057,
+                  "src": "27152:7:1",
+                  "stateVariable": false,
+                  "storageLocation": "default",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_uint256",
+                    "typeString": "uint256"
+                  },
+                  "typeName": {
+                    "id": 1041,
+                    "name": "uint256",
+                    "nodeType": "ElementaryTypeName",
+                    "src": "27152:7:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_uint256",
+                      "typeString": "uint256"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                }
+              ],
+              "src": "27151:9:1"
+            },
+            "scope": 1302,
+            "src": "27094:196:1",
+            "stateMutability": "view",
+            "superFunction": 968,
+            "visibility": "public"
+          },
+          {
+            "body": {
+              "id": 1084,
+              "nodeType": "Block",
+              "src": "27740:164:1",
+              "statements": [
+                {
+                  "expression": {
+                    "argumentTypes": null,
+                    "arguments": [
+                      {
+                        "argumentTypes": null,
+                        "id": 1069,
+                        "name": "from",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 1059,
+                        "src": "27770:4:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        }
+                      },
+                      {
+                        "argumentTypes": null,
+                        "id": 1070,
+                        "name": "to",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 1061,
+                        "src": "27776:2:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        }
+                      },
+                      {
+                        "argumentTypes": null,
+                        "id": 1071,
+                        "name": "tokenId",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 1063,
+                        "src": "27780:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      }
+                    ],
+                    "expression": {
+                      "argumentTypes": [
+                        {
+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        },
+                        {
+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        },
+                        {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      ],
+                      "expression": {
+                        "argumentTypes": null,
+                        "id": 1066,
+                        "name": "super",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 1572,
+                        "src": "27750:5:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_super$_ERC721Enumerable_$1302",
+                          "typeString": "contract super ERC721Enumerable"
+                        }
+                      },
+                      "id": 1068,
+                      "isConstant": false,
+                      "isLValue": false,
+                      "isPure": false,
+                      "lValueRequested": false,
+                      "memberName": "_transferFrom",
+                      "nodeType": "MemberAccess",
+                      "referencedDeclaration": 880,
+                      "src": "27750:19:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_function_internal_nonpayable$_t_address_$_t_address_$_t_uint256_$returns$__$",
+                        "typeString": "function (address,address,uint256)"
+                      }
+                    },
+                    "id": 1072,
+                    "isConstant": false,
+                    "isLValue": false,
+                    "isPure": false,
+                    "kind": "functionCall",
+                    "lValueRequested": false,
+                    "names": [],
+                    "nodeType": "FunctionCall",
+                    "src": "27750:38:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_tuple$__$",
+                      "typeString": "tuple()"
+                    }
+                  },
+                  "id": 1073,
+                  "nodeType": "ExpressionStatement",
+                  "src": "27750:38:1"
+                },
+                {
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+                    "argumentTypes": null,
+                    "arguments": [
+                      {
+                        "argumentTypes": null,
+                        "id": 1075,
+                        "name": "from",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 1059,
+                        "src": "27832:4:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        }
+                      },
+                      {
+                        "argumentTypes": null,
+                        "id": 1076,
+                        "name": "tokenId",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 1063,
+                        "src": "27838:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      }
+                    ],
+                    "expression": {
+                      "argumentTypes": [
+                        {
+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        },
+                        {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      ],
+                      "id": 1074,
+                      "name": "_removeTokenFromOwnerEnumeration",
+                      "nodeType": "Identifier",
+                      "overloadedDeclarations": [],
+                      "referencedDeclaration": 1252,
+                      "src": "27799:32:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_function_internal_nonpayable$_t_address_$_t_uint256_$returns$__$",
+                        "typeString": "function (address,uint256)"
+                      }
+                    },
+                    "id": 1077,
+                    "isConstant": false,
+                    "isLValue": false,
+                    "isPure": false,
+                    "kind": "functionCall",
+                    "lValueRequested": false,
+                    "names": [],
+                    "nodeType": "FunctionCall",
+                    "src": "27799:47:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_tuple$__$",
+                      "typeString": "tuple()"
+                    }
+                  },
+                  "id": 1078,
+                  "nodeType": "ExpressionStatement",
+                  "src": "27799:47:1"
+                },
+                {
+                  "expression": {
+                    "argumentTypes": null,
+                    "arguments": [
+                      {
+                        "argumentTypes": null,
+                        "id": 1080,
+                        "name": "to",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 1061,
+                        "src": "27885:2:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        }
+                      },
+                      {
+                        "argumentTypes": null,
+                        "id": 1081,
+                        "name": "tokenId",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 1063,
+                        "src": "27889:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      }
+                    ],
+                    "expression": {
+                      "argumentTypes": [
+                        {
+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        },
+                        {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      ],
+                      "id": 1079,
+                      "name": "_addTokenToOwnerEnumeration",
+                      "nodeType": "Identifier",
+                      "overloadedDeclarations": [],
+                      "referencedDeclaration": 1176,
+                      "src": "27857:27:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_function_internal_nonpayable$_t_address_$_t_uint256_$returns$__$",
+                        "typeString": "function (address,uint256)"
+                      }
+                    },
+                    "id": 1082,
+                    "isConstant": false,
+                    "isLValue": false,
+                    "isPure": false,
+                    "kind": "functionCall",
+                    "lValueRequested": false,
+                    "names": [],
+                    "nodeType": "FunctionCall",
+                    "src": "27857:40:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_tuple$__$",
+                      "typeString": "tuple()"
+                    }
+                  },
+                  "id": 1083,
+                  "nodeType": "ExpressionStatement",
+                  "src": "27857:40:1"
+                }
+              ]
+            },
+            "documentation": "@dev Internal function to transfer ownership of a given token ID to another address.\nAs opposed to transferFrom, this imposes no restrictions on msg.sender.\n@param from current owner of the token\n@param to address to receive the ownership of the given token ID\n@param tokenId uint256 ID of the token to be transferred",
+            "id": 1085,
+            "implemented": true,
+            "kind": "function",
+            "modifiers": [],
+            "name": "_transferFrom",
+            "nodeType": "FunctionDefinition",
+            "parameters": {
+              "id": 1064,
+              "nodeType": "ParameterList",
+              "parameters": [
+                {
+                  "constant": false,
+                  "id": 1059,
+                  "name": "from",
+                  "nodeType": "VariableDeclaration",
+                  "scope": 1085,
+                  "src": "27688:12:1",
+                  "stateVariable": false,
+                  "storageLocation": "default",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_address",
+                    "typeString": "address"
+                  },
+                  "typeName": {
+                    "id": 1058,
+                    "name": "address",
+                    "nodeType": "ElementaryTypeName",
+                    "src": "27688:7:1",
+                    "stateMutability": "nonpayable",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_address",
+                      "typeString": "address"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                },
+                {
+                  "constant": false,
+                  "id": 1061,
+                  "name": "to",
+                  "nodeType": "VariableDeclaration",
+                  "scope": 1085,
+                  "src": "27702:10:1",
+                  "stateVariable": false,
+                  "storageLocation": "default",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_address",
+                    "typeString": "address"
+                  },
+                  "typeName": {
+                    "id": 1060,
+                    "name": "address",
+                    "nodeType": "ElementaryTypeName",
+                    "src": "27702:7:1",
+                    "stateMutability": "nonpayable",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_address",
+                      "typeString": "address"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                },
+                {
+                  "constant": false,
+                  "id": 1063,
+                  "name": "tokenId",
+                  "nodeType": "VariableDeclaration",
+                  "scope": 1085,
+                  "src": "27714:15:1",
+                  "stateVariable": false,
+                  "storageLocation": "default",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_uint256",
+                    "typeString": "uint256"
+                  },
+                  "typeName": {
+                    "id": 1062,
+                    "name": "uint256",
+                    "nodeType": "ElementaryTypeName",
+                    "src": "27714:7:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_uint256",
+                      "typeString": "uint256"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                }
+              ],
+              "src": "27687:43:1"
+            },
+            "returnParameters": {
+              "id": 1065,
+              "nodeType": "ParameterList",
+              "parameters": [],
+              "src": "27740:0:1"
+            },
+            "scope": 1302,
+            "src": "27665:239:1",
+            "stateMutability": "nonpayable",
+            "superFunction": 880,
+            "visibility": "internal"
+          },
+          {
+            "body": {
+              "id": 1108,
+              "nodeType": "Block",
+              "src": "28214:143:1",
+              "statements": [
+                {
+                  "expression": {
+                    "argumentTypes": null,
+                    "arguments": [
+                      {
+                        "argumentTypes": null,
+                        "id": 1095,
+                        "name": "to",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 1087,
+                        "src": "28236:2:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        }
+                      },
+                      {
+                        "argumentTypes": null,
+                        "id": 1096,
+                        "name": "tokenId",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 1089,
+                        "src": "28240:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      }
+                    ],
+                    "expression": {
+                      "argumentTypes": [
+                        {
+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        },
+                        {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      ],
+                      "expression": {
+                        "argumentTypes": null,
+                        "id": 1092,
+                        "name": "super",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 1572,
+                        "src": "28224:5:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_super$_ERC721Enumerable_$1302",
+                          "typeString": "contract super ERC721Enumerable"
+                        }
+                      },
+                      "id": 1094,
+                      "isConstant": false,
+                      "isLValue": false,
+                      "isPure": false,
+                      "lValueRequested": false,
+                      "memberName": "_mint",
+                      "nodeType": "MemberAccess",
+                      "referencedDeclaration": 768,
+                      "src": "28224:11:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_function_internal_nonpayable$_t_address_$_t_uint256_$returns$__$",
+                        "typeString": "function (address,uint256)"
+                      }
+                    },
+                    "id": 1097,
+                    "isConstant": false,
+                    "isLValue": false,
+                    "isPure": false,
+                    "kind": "functionCall",
+                    "lValueRequested": false,
+                    "names": [],
+                    "nodeType": "FunctionCall",
+                    "src": "28224:24:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_tuple$__$",
+                      "typeString": "tuple()"
+                    }
+                  },
+                  "id": 1098,
+                  "nodeType": "ExpressionStatement",
+                  "src": "28224:24:1"
+                },
+                {
+                  "expression": {
+                    "argumentTypes": null,
+                    "arguments": [
+                      {
+                        "argumentTypes": null,
+                        "id": 1100,
+                        "name": "to",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 1087,
+                        "src": "28287:2:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        }
+                      },
+                      {
+                        "argumentTypes": null,
+                        "id": 1101,
+                        "name": "tokenId",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 1089,
+                        "src": "28291:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      }
+                    ],
+                    "expression": {
+                      "argumentTypes": [
+                        {
+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        },
+                        {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      ],
+                      "id": 1099,
+                      "name": "_addTokenToOwnerEnumeration",
+                      "nodeType": "Identifier",
+                      "overloadedDeclarations": [],
+                      "referencedDeclaration": 1176,
+                      "src": "28259:27:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_function_internal_nonpayable$_t_address_$_t_uint256_$returns$__$",
+                        "typeString": "function (address,uint256)"
+                      }
+                    },
+                    "id": 1102,
+                    "isConstant": false,
+                    "isLValue": false,
+                    "isPure": false,
+                    "kind": "functionCall",
+                    "lValueRequested": false,
+                    "names": [],
+                    "nodeType": "FunctionCall",
+                    "src": "28259:40:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_tuple$__$",
+                      "typeString": "tuple()"
+                    }
+                  },
+                  "id": 1103,
+                  "nodeType": "ExpressionStatement",
+                  "src": "28259:40:1"
+                },
+                {
+                  "expression": {
+                    "argumentTypes": null,
+                    "arguments": [
+                      {
+                        "argumentTypes": null,
+                        "id": 1105,
+                        "name": "tokenId",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 1089,
+                        "src": "28342:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      }
+                    ],
+                    "expression": {
+                      "argumentTypes": [
+                        {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      ],
+                      "id": 1104,
+                      "name": "_addTokenToAllTokensEnumeration",
+                      "nodeType": "Identifier",
+                      "overloadedDeclarations": [],
+                      "referencedDeclaration": 1195,
+                      "src": "28310:31:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_function_internal_nonpayable$_t_uint256_$returns$__$",
+                        "typeString": "function (uint256)"
+                      }
+                    },
+                    "id": 1106,
+                    "isConstant": false,
+                    "isLValue": false,
+                    "isPure": false,
+                    "kind": "functionCall",
+                    "lValueRequested": false,
+                    "names": [],
+                    "nodeType": "FunctionCall",
+                    "src": "28310:40:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_tuple$__$",
+                      "typeString": "tuple()"
+                    }
+                  },
+                  "id": 1107,
+                  "nodeType": "ExpressionStatement",
+                  "src": "28310:40:1"
+                }
+              ]
+            },
+            "documentation": "@dev Internal function to mint a new token.\nReverts if the given token ID already exists.\n@param to address the beneficiary that will own the minted token\n@param tokenId uint256 ID of the token to be minted",
+            "id": 1109,
+            "implemented": true,
+            "kind": "function",
+            "modifiers": [],
+            "name": "_mint",
+            "nodeType": "FunctionDefinition",
+            "parameters": {
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+              "nodeType": "ParameterList",
+              "parameters": [
+                {
+                  "constant": false,
+                  "id": 1087,
+                  "name": "to",
+                  "nodeType": "VariableDeclaration",
+                  "scope": 1109,
+                  "src": "28176:10:1",
+                  "stateVariable": false,
+                  "storageLocation": "default",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_address",
+                    "typeString": "address"
+                  },
+                  "typeName": {
+                    "id": 1086,
+                    "name": "address",
+                    "nodeType": "ElementaryTypeName",
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+                    "stateMutability": "nonpayable",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_address",
+                      "typeString": "address"
+                    }
+                  },
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+                  "visibility": "internal"
+                },
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+                  "stateVariable": false,
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+                    "typeString": "uint256"
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+                      "typeString": "uint256"
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+                  "visibility": "internal"
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+            "src": "28161:196:1",
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+            "visibility": "internal"
+          },
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+                        "src": "28710:5:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        }
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+                        "name": "tokenId",
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+                        "src": "28717:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
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+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        },
+                        {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
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+                        "src": "28698:5:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_super$_ERC721Enumerable_$1302",
+                          "typeString": "contract super ERC721Enumerable"
+                        }
+                      },
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+                      "isConstant": false,
+                      "isLValue": false,
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+                      "lValueRequested": false,
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+                      "src": "28698:11:1",
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+                        "typeString": "function (address,uint256)"
+                      }
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+                        "src": "28769:5:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        }
+                      },
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+                        "id": 1125,
+                        "name": "tokenId",
+                        "nodeType": "Identifier",
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+                        "src": "28776:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      }
+                    ],
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+                        {
+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        },
+                        {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      ],
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+                      "name": "_removeTokenFromOwnerEnumeration",
+                      "nodeType": "Identifier",
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+                      "src": "28736:32:1",
+                      "typeDescriptions": {
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+                        "typeString": "function (address,uint256)"
+                      }
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+                    "isPure": false,
+                    "kind": "functionCall",
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+                    "nodeType": "FunctionCall",
+                    "src": "28736:48:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_tuple$__$",
+                      "typeString": "tuple()"
+                    }
+                  },
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+                  "src": "28736:48:1"
+                },
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+                    "lValueRequested": false,
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+                      "baseExpression": {
+                        "argumentTypes": null,
+                        "id": 1128,
+                        "name": "_ownedTokensIndex",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 985,
+                        "src": "28903:17:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_mapping$_t_uint256_$_t_uint256_$",
+                          "typeString": "mapping(uint256 => uint256)"
+                        }
+                      },
+                      "id": 1130,
+                      "indexExpression": {
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+                        "id": 1129,
+                        "name": "tokenId",
+                        "nodeType": "Identifier",
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+                        "referencedDeclaration": 1113,
+                        "src": "28921:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
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+                      "isLValue": true,
+                      "isPure": false,
+                      "lValueRequested": true,
+                      "nodeType": "IndexAccess",
+                      "src": "28903:26:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_uint256",
+                        "typeString": "uint256"
+                      }
+                    },
+                    "nodeType": "Assignment",
+                    "operator": "=",
+                    "rightHandSide": {
+                      "argumentTypes": null,
+                      "hexValue": "30",
+                      "id": 1131,
+                      "isConstant": false,
+                      "isLValue": false,
+                      "isPure": true,
+                      "kind": "number",
+                      "lValueRequested": false,
+                      "nodeType": "Literal",
+                      "src": "28932:1:1",
+                      "subdenomination": null,
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_rational_0_by_1",
+                        "typeString": "int_const 0"
+                      },
+                      "value": "0"
+                    },
+                    "src": "28903:30:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_uint256",
+                      "typeString": "uint256"
+                    }
+                  },
+                  "id": 1133,
+                  "nodeType": "ExpressionStatement",
+                  "src": "28903:30:1"
+                },
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+                    "arguments": [
+                      {
+                        "argumentTypes": null,
+                        "id": 1135,
+                        "name": "tokenId",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 1113,
+                        "src": "28981:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      }
+                    ],
+                    "expression": {
+                      "argumentTypes": [
+                        {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      ],
+                      "id": 1134,
+                      "name": "_removeTokenFromAllTokensEnumeration",
+                      "nodeType": "Identifier",
+                      "overloadedDeclarations": [],
+                      "referencedDeclaration": 1301,
+                      "src": "28944:36:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_function_internal_nonpayable$_t_uint256_$returns$__$",
+                        "typeString": "function (uint256)"
+                      }
+                    },
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+                    "isConstant": false,
+                    "isLValue": false,
+                    "isPure": false,
+                    "kind": "functionCall",
+                    "lValueRequested": false,
+                    "names": [],
+                    "nodeType": "FunctionCall",
+                    "src": "28944:45:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_tuple$__$",
+                      "typeString": "tuple()"
+                    }
+                  },
+                  "id": 1137,
+                  "nodeType": "ExpressionStatement",
+                  "src": "28944:45:1"
+                }
+              ]
+            },
+            "documentation": "@dev Internal function to burn a specific token.\nReverts if the token does not exist.\nDeprecated, use _burn(uint256) instead.\n@param owner owner of the token to burn\n@param tokenId uint256 ID of the token being burned",
+            "id": 1139,
+            "implemented": true,
+            "kind": "function",
+            "modifiers": [],
+            "name": "_burn",
+            "nodeType": "FunctionDefinition",
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+              "id": 1114,
+              "nodeType": "ParameterList",
+              "parameters": [
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+                  "constant": false,
+                  "id": 1111,
+                  "name": "owner",
+                  "nodeType": "VariableDeclaration",
+                  "scope": 1139,
+                  "src": "28647:13:1",
+                  "stateVariable": false,
+                  "storageLocation": "default",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_address",
+                    "typeString": "address"
+                  },
+                  "typeName": {
+                    "id": 1110,
+                    "name": "address",
+                    "nodeType": "ElementaryTypeName",
+                    "src": "28647:7:1",
+                    "stateMutability": "nonpayable",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_address",
+                      "typeString": "address"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                },
+                {
+                  "constant": false,
+                  "id": 1113,
+                  "name": "tokenId",
+                  "nodeType": "VariableDeclaration",
+                  "scope": 1139,
+                  "src": "28662:15:1",
+                  "stateVariable": false,
+                  "storageLocation": "default",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_uint256",
+                    "typeString": "uint256"
+                  },
+                  "typeName": {
+                    "id": 1112,
+                    "name": "uint256",
+                    "nodeType": "ElementaryTypeName",
+                    "src": "28662:7:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_uint256",
+                      "typeString": "uint256"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                }
+              ],
+              "src": "28646:32:1"
+            },
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+              "nodeType": "ParameterList",
+              "parameters": [],
+              "src": "28688:0:1"
+            },
+            "scope": 1302,
+            "src": "28632:364:1",
+            "stateMutability": "nonpayable",
+            "superFunction": 811,
+            "visibility": "internal"
+          },
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+            "body": {
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+              "nodeType": "Block",
+              "src": "29282:43:1",
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+                {
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+                    "baseExpression": {
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+                      "id": 1147,
+                      "name": "_ownedTokens",
+                      "nodeType": "Identifier",
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+                      "referencedDeclaration": 981,
+                      "src": "29299:12:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_mapping$_t_address_$_t_array$_t_uint256_$dyn_storage_$",
+                        "typeString": "mapping(address => uint256[] storage ref)"
+                      }
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+                      "id": 1148,
+                      "name": "owner",
+                      "nodeType": "Identifier",
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+                      "referencedDeclaration": 1141,
+                      "src": "29312:5:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_address",
+                        "typeString": "address"
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+                    "isLValue": true,
+                    "isPure": false,
+                    "lValueRequested": false,
+                    "nodeType": "IndexAccess",
+                    "src": "29299:19:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_array$_t_uint256_$dyn_storage",
+                      "typeString": "uint256[] storage ref"
+                    }
+                  },
+                  "functionReturnParameters": 1146,
+                  "id": 1150,
+                  "nodeType": "Return",
+                  "src": "29292:26:1"
+                }
+              ]
+            },
+            "documentation": "@dev Gets the list of token IDs of the requested owner.\n@param owner address owning the tokens\n@return uint256[] List of token IDs owned by the requested address",
+            "id": 1152,
+            "implemented": true,
+            "kind": "function",
+            "modifiers": [],
+            "name": "_tokensOfOwner",
+            "nodeType": "FunctionDefinition",
+            "parameters": {
+              "id": 1142,
+              "nodeType": "ParameterList",
+              "parameters": [
+                {
+                  "constant": false,
+                  "id": 1141,
+                  "name": "owner",
+                  "nodeType": "VariableDeclaration",
+                  "scope": 1152,
+                  "src": "29225:13:1",
+                  "stateVariable": false,
+                  "storageLocation": "default",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_address",
+                    "typeString": "address"
+                  },
+                  "typeName": {
+                    "id": 1140,
+                    "name": "address",
+                    "nodeType": "ElementaryTypeName",
+                    "src": "29225:7:1",
+                    "stateMutability": "nonpayable",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_address",
+                      "typeString": "address"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                }
+              ],
+              "src": "29224:15:1"
+            },
+            "returnParameters": {
+              "id": 1146,
+              "nodeType": "ParameterList",
+              "parameters": [
+                {
+                  "constant": false,
+                  "id": 1145,
+                  "name": "",
+                  "nodeType": "VariableDeclaration",
+                  "scope": 1152,
+                  "src": "29263:17:1",
+                  "stateVariable": false,
+                  "storageLocation": "storage",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_array$_t_uint256_$dyn_storage_ptr",
+                    "typeString": "uint256[]"
+                  },
+                  "typeName": {
+                    "baseType": {
+                      "id": 1143,
+                      "name": "uint256",
+                      "nodeType": "ElementaryTypeName",
+                      "src": "29263:7:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_uint256",
+                        "typeString": "uint256"
+                      }
+                    },
+                    "id": 1144,
+                    "length": null,
+                    "nodeType": "ArrayTypeName",
+                    "src": "29263:9:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_array$_t_uint256_$dyn_storage_ptr",
+                      "typeString": "uint256[]"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                }
+              ],
+              "src": "29262:19:1"
+            },
+            "scope": 1302,
+            "src": "29201:124:1",
+            "stateMutability": "view",
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+            "visibility": "internal"
+          },
+          {
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+              "nodeType": "Block",
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+                    "id": 1166,
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+                        "argumentTypes": null,
+                        "id": 1159,
+                        "name": "_ownedTokensIndex",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 985,
+                        "src": "29703:17:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_mapping$_t_uint256_$_t_uint256_$",
+                          "typeString": "mapping(uint256 => uint256)"
+                        }
+                      },
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+                        "id": 1160,
+                        "name": "tokenId",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 1156,
+                        "src": "29721:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
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+                      "isLValue": true,
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+                      "lValueRequested": true,
+                      "nodeType": "IndexAccess",
+                      "src": "29703:26:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_uint256",
+                        "typeString": "uint256"
+                      }
+                    },
+                    "nodeType": "Assignment",
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+                      "argumentTypes": null,
+                      "expression": {
+                        "argumentTypes": null,
+                        "baseExpression": {
+                          "argumentTypes": null,
+                          "id": 1162,
+                          "name": "_ownedTokens",
+                          "nodeType": "Identifier",
+                          "overloadedDeclarations": [],
+                          "referencedDeclaration": 981,
+                          "src": "29732:12:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_mapping$_t_address_$_t_array$_t_uint256_$dyn_storage_$",
+                            "typeString": "mapping(address => uint256[] storage ref)"
+                          }
+                        },
+                        "id": 1164,
+                        "indexExpression": {
+                          "argumentTypes": null,
+                          "id": 1163,
+                          "name": "to",
+                          "nodeType": "Identifier",
+                          "overloadedDeclarations": [],
+                          "referencedDeclaration": 1154,
+                          "src": "29745:2:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_address",
+                            "typeString": "address"
+                          }
+                        },
+                        "isConstant": false,
+                        "isLValue": true,
+                        "isPure": false,
+                        "lValueRequested": false,
+                        "nodeType": "IndexAccess",
+                        "src": "29732:16:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_array$_t_uint256_$dyn_storage",
+                          "typeString": "uint256[] storage ref"
+                        }
+                      },
+                      "id": 1165,
+                      "isConstant": false,
+                      "isLValue": true,
+                      "isPure": false,
+                      "lValueRequested": false,
+                      "memberName": "length",
+                      "nodeType": "MemberAccess",
+                      "referencedDeclaration": null,
+                      "src": "29732:23:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_uint256",
+                        "typeString": "uint256"
+                      }
+                    },
+                    "src": "29703:52:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_uint256",
+                      "typeString": "uint256"
+                    }
+                  },
+                  "id": 1167,
+                  "nodeType": "ExpressionStatement",
+                  "src": "29703:52:1"
+                },
+                {
+                  "expression": {
+                    "argumentTypes": null,
+                    "arguments": [
+                      {
+                        "argumentTypes": null,
+                        "id": 1172,
+                        "name": "tokenId",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 1156,
+                        "src": "29787:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      }
+                    ],
+                    "expression": {
+                      "argumentTypes": [
+                        {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      ],
+                      "expression": {
+                        "argumentTypes": null,
+                        "baseExpression": {
+                          "argumentTypes": null,
+                          "id": 1168,
+                          "name": "_ownedTokens",
+                          "nodeType": "Identifier",
+                          "overloadedDeclarations": [],
+                          "referencedDeclaration": 981,
+                          "src": "29765:12:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_mapping$_t_address_$_t_array$_t_uint256_$dyn_storage_$",
+                            "typeString": "mapping(address => uint256[] storage ref)"
+                          }
+                        },
+                        "id": 1170,
+                        "indexExpression": {
+                          "argumentTypes": null,
+                          "id": 1169,
+                          "name": "to",
+                          "nodeType": "Identifier",
+                          "overloadedDeclarations": [],
+                          "referencedDeclaration": 1154,
+                          "src": "29778:2:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_address",
+                            "typeString": "address"
+                          }
+                        },
+                        "isConstant": false,
+                        "isLValue": true,
+                        "isPure": false,
+                        "lValueRequested": false,
+                        "nodeType": "IndexAccess",
+                        "src": "29765:16:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_array$_t_uint256_$dyn_storage",
+                          "typeString": "uint256[] storage ref"
+                        }
+                      },
+                      "id": 1171,
+                      "isConstant": false,
+                      "isLValue": false,
+                      "isPure": false,
+                      "lValueRequested": false,
+                      "memberName": "push",
+                      "nodeType": "MemberAccess",
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+                              "isPure": false,
+                              "lValueRequested": false,
+                              "nodeType": "IndexAccess",
+                              "src": "31368:18:1",
+                              "typeDescriptions": {
+                                "typeIdentifier": "t_array$_t_uint256_$dyn_storage",
+                                "typeString": "uint256[] storage ref"
+                              }
+                            },
+                            "id": 1233,
+                            "indexExpression": {
+                              "argumentTypes": null,
+                              "id": 1231,
+                              "name": "tokenIndex",
+                              "nodeType": "Identifier",
+                              "overloadedDeclarations": [],
+                              "referencedDeclaration": 1213,
+                              "src": "31387:10:1",
+                              "typeDescriptions": {
+                                "typeIdentifier": "t_uint256",
+                                "typeString": "uint256"
+                              }
+                            },
+                            "isConstant": false,
+                            "isLValue": true,
+                            "isPure": false,
+                            "lValueRequested": true,
+                            "nodeType": "IndexAccess",
+                            "src": "31368:30:1",
+                            "typeDescriptions": {
+                              "typeIdentifier": "t_uint256",
+                              "typeString": "uint256"
+                            }
+                          },
+                          "nodeType": "Assignment",
+                          "operator": "=",
+                          "rightHandSide": {
+                            "argumentTypes": null,
+                            "id": 1234,
+                            "name": "lastTokenId",
+                            "nodeType": "Identifier",
+                            "overloadedDeclarations": [],
+                            "referencedDeclaration": 1222,
+                            "src": "31401:11:1",
+                            "typeDescriptions": {
+                              "typeIdentifier": "t_uint256",
+                              "typeString": "uint256"
+                            }
+                          },
+                          "src": "31368:44:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_uint256",
+                            "typeString": "uint256"
+                          }
+                        },
+                        "id": 1236,
+                        "nodeType": "ExpressionStatement",
+                        "src": "31368:44:1"
+                      },
+                      {
+                        "expression": {
+                          "argumentTypes": null,
+                          "id": 1241,
+                          "isConstant": false,
+                          "isLValue": false,
+                          "isPure": false,
+                          "lValueRequested": false,
+                          "leftHandSide": {
+                            "argumentTypes": null,
+                            "baseExpression": {
+                              "argumentTypes": null,
+                              "id": 1237,
+                              "name": "_ownedTokensIndex",
+                              "nodeType": "Identifier",
+                              "overloadedDeclarations": [],
+                              "referencedDeclaration": 985,
+                              "src": "31484:17:1",
+                              "typeDescriptions": {
+                                "typeIdentifier": "t_mapping$_t_uint256_$_t_uint256_$",
+                                "typeString": "mapping(uint256 => uint256)"
+                              }
+                            },
+                            "id": 1239,
+                            "indexExpression": {
+                              "argumentTypes": null,
+                              "id": 1238,
+                              "name": "lastTokenId",
+                              "nodeType": "Identifier",
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+                              "referencedDeclaration": 1222,
+                              "src": "31502:11:1",
+                              "typeDescriptions": {
+                                "typeIdentifier": "t_uint256",
+                                "typeString": "uint256"
+                              }
+                            },
+                            "isConstant": false,
+                            "isLValue": true,
+                            "isPure": false,
+                            "lValueRequested": true,
+                            "nodeType": "IndexAccess",
+                            "src": "31484:30:1",
+                            "typeDescriptions": {
+                              "typeIdentifier": "t_uint256",
+                              "typeString": "uint256"
+                            }
+                          },
+                          "nodeType": "Assignment",
+                          "operator": "=",
+                          "rightHandSide": {
+                            "argumentTypes": null,
+                            "id": 1240,
+                            "name": "tokenIndex",
+                            "nodeType": "Identifier",
+                            "overloadedDeclarations": [],
+                            "referencedDeclaration": 1213,
+                            "src": "31517:10:1",
+                            "typeDescriptions": {
+                              "typeIdentifier": "t_uint256",
+                              "typeString": "uint256"
+                            }
+                          },
+                          "src": "31484:43:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_uint256",
+                            "typeString": "uint256"
+                          }
+                        },
+                        "id": 1242,
+                        "nodeType": "ExpressionStatement",
+                        "src": "31484:43:1"
+                      }
+                    ]
+                  }
+                },
+                {
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+                    "id": 1249,
+                    "isConstant": false,
+                    "isLValue": false,
+                    "isPure": false,
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+                    "prefix": false,
+                    "src": "31658:27:1",
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+                      "expression": {
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+                        "baseExpression": {
+                          "argumentTypes": null,
+                          "id": 1245,
+                          "name": "_ownedTokens",
+                          "nodeType": "Identifier",
+                          "overloadedDeclarations": [],
+                          "referencedDeclaration": 981,
+                          "src": "31658:12:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_mapping$_t_address_$_t_array$_t_uint256_$dyn_storage_$",
+                            "typeString": "mapping(address => uint256[] storage ref)"
+                          }
+                        },
+                        "id": 1247,
+                        "indexExpression": {
+                          "argumentTypes": null,
+                          "id": 1246,
+                          "name": "from",
+                          "nodeType": "Identifier",
+                          "overloadedDeclarations": [],
+                          "referencedDeclaration": 1197,
+                          "src": "31671:4:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_address",
+                            "typeString": "address"
+                          }
+                        },
+                        "isConstant": false,
+                        "isLValue": true,
+                        "isPure": false,
+                        "lValueRequested": false,
+                        "nodeType": "IndexAccess",
+                        "src": "31658:18:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_array$_t_uint256_$dyn_storage",
+                          "typeString": "uint256[] storage ref"
+                        }
+                      },
+                      "id": 1248,
+                      "isConstant": false,
+                      "isLValue": true,
+                      "isPure": false,
+                      "lValueRequested": true,
+                      "memberName": "length",
+                      "nodeType": "MemberAccess",
+                      "referencedDeclaration": null,
+                      "src": "31658:25:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_uint256",
+                        "typeString": "uint256"
+                      }
+                    },
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+                      "typeIdentifier": "t_uint256",
+                      "typeString": "uint256"
+                    }
+                  },
+                  "id": 1250,
+                  "nodeType": "ExpressionStatement",
+                  "src": "31658:27:1"
+                }
+              ]
+            },
+            "documentation": "@dev Private function to remove a token from this extension's ownership-tracking data structures. Note that\nwhile the token is not assigned a new owner, the _ownedTokensIndex mapping is _not_ updated: this allows for\ngas optimizations e.g. when performing a transfer operation (avoiding double writes).\nThis has O(1) time complexity, but alters the order of the _ownedTokens array.\n@param from address representing the previous owner of the given token ID\n@param tokenId uint256 ID of the token to be removed from the tokens list of the given address",
+            "id": 1252,
+            "implemented": true,
+            "kind": "function",
+            "modifiers": [],
+            "name": "_removeTokenFromOwnerEnumeration",
+            "nodeType": "FunctionDefinition",
+            "parameters": {
+              "id": 1200,
+              "nodeType": "ParameterList",
+              "parameters": [
+                {
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+                  "id": 1197,
+                  "name": "from",
+                  "nodeType": "VariableDeclaration",
+                  "scope": 1252,
+                  "src": "30815:12:1",
+                  "stateVariable": false,
+                  "storageLocation": "default",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_address",
+                    "typeString": "address"
+                  },
+                  "typeName": {
+                    "id": 1196,
+                    "name": "address",
+                    "nodeType": "ElementaryTypeName",
+                    "src": "30815:7:1",
+                    "stateMutability": "nonpayable",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_address",
+                      "typeString": "address"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                },
+                {
+                  "constant": false,
+                  "id": 1199,
+                  "name": "tokenId",
+                  "nodeType": "VariableDeclaration",
+                  "scope": 1252,
+                  "src": "30829:15:1",
+                  "stateVariable": false,
+                  "storageLocation": "default",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_uint256",
+                    "typeString": "uint256"
+                  },
+                  "typeName": {
+                    "id": 1198,
+                    "name": "uint256",
+                    "nodeType": "ElementaryTypeName",
+                    "src": "30829:7:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_uint256",
+                      "typeString": "uint256"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                }
+              ],
+              "src": "30814:31:1"
+            },
+            "returnParameters": {
+              "id": 1201,
+              "nodeType": "ParameterList",
+              "parameters": [],
+              "src": "30854:0:1"
+            },
+            "scope": 1302,
+            "src": "30773:1128:1",
+            "stateMutability": "nonpayable",
+            "superFunction": null,
+            "visibility": "private"
+          },
+          {
+            "body": {
+              "id": 1300,
+              "nodeType": "Block",
+              "src": "32260:993:1",
+              "statements": [
+                {
+                  "assignments": [
+                    1258
+                  ],
+                  "declarations": [
+                    {
+                      "constant": false,
+                      "id": 1258,
+                      "name": "lastTokenIndex",
+                      "nodeType": "VariableDeclaration",
+                      "scope": 1300,
+                      "src": "32438:22:1",
+                      "stateVariable": false,
+                      "storageLocation": "default",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_uint256",
+                        "typeString": "uint256"
+                      },
+                      "typeName": {
+                        "id": 1257,
+                        "name": "uint256",
+                        "nodeType": "ElementaryTypeName",
+                        "src": "32438:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      },
+                      "value": null,
+                      "visibility": "internal"
+                    }
+                  ],
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+                  "initialValue": {
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+                    "arguments": [
+                      {
+                        "argumentTypes": null,
+                        "hexValue": "31",
+                        "id": 1262,
+                        "isConstant": false,
+                        "isLValue": false,
+                        "isPure": true,
+                        "kind": "number",
+                        "lValueRequested": false,
+                        "nodeType": "Literal",
+                        "src": "32485:1:1",
+                        "subdenomination": null,
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_rational_1_by_1",
+                          "typeString": "int_const 1"
+                        },
+                        "value": "1"
+                      }
+                    ],
+                    "expression": {
+                      "argumentTypes": [
+                        {
+                          "typeIdentifier": "t_rational_1_by_1",
+                          "typeString": "int_const 1"
+                        }
+                      ],
+                      "expression": {
+                        "argumentTypes": null,
+                        "expression": {
+                          "argumentTypes": null,
+                          "id": 1259,
+                          "name": "_allTokens",
+                          "nodeType": "Identifier",
+                          "overloadedDeclarations": [],
+                          "referencedDeclaration": 988,
+                          "src": "32463:10:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_array$_t_uint256_$dyn_storage",
+                            "typeString": "uint256[] storage ref"
+                          }
+                        },
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+                        "isConstant": false,
+                        "isLValue": true,
+                        "isPure": false,
+                        "lValueRequested": false,
+                        "memberName": "length",
+                        "nodeType": "MemberAccess",
+                        "referencedDeclaration": null,
+                        "src": "32463:17:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
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+                      "id": 1261,
+                      "isConstant": false,
+                      "isLValue": false,
+                      "isPure": false,
+                      "lValueRequested": false,
+                      "memberName": "sub",
+                      "nodeType": "MemberAccess",
+                      "referencedDeclaration": 190,
+                      "src": "32463:21:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_function_internal_pure$_t_uint256_$_t_uint256_$returns$_t_uint256_$bound_to$_t_uint256_$",
+                        "typeString": "function (uint256,uint256) pure returns (uint256)"
+                      }
+                    },
+                    "id": 1263,
+                    "isConstant": false,
+                    "isLValue": false,
+                    "isPure": false,
+                    "kind": "functionCall",
+                    "lValueRequested": false,
+                    "names": [],
+                    "nodeType": "FunctionCall",
+                    "src": "32463:24:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_uint256",
+                      "typeString": "uint256"
+                    }
+                  },
+                  "nodeType": "VariableDeclarationStatement",
+                  "src": "32438:49:1"
+                },
+                {
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+                  ],
+                  "declarations": [
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+                      "constant": false,
+                      "id": 1266,
+                      "name": "tokenIndex",
+                      "nodeType": "VariableDeclaration",
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+                      "src": "32497:18:1",
+                      "stateVariable": false,
+                      "storageLocation": "default",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_uint256",
+                        "typeString": "uint256"
+                      },
+                      "typeName": {
+                        "id": 1265,
+                        "name": "uint256",
+                        "nodeType": "ElementaryTypeName",
+                        "src": "32497:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      },
+                      "value": null,
+                      "visibility": "internal"
+                    }
+                  ],
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+                  "initialValue": {
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+                    "baseExpression": {
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+                      "id": 1267,
+                      "name": "_allTokensIndex",
+                      "nodeType": "Identifier",
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+                      "referencedDeclaration": 992,
+                      "src": "32518:15:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_mapping$_t_uint256_$_t_uint256_$",
+                        "typeString": "mapping(uint256 => uint256)"
+                      }
+                    },
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+                    "indexExpression": {
+                      "argumentTypes": null,
+                      "id": 1268,
+                      "name": "tokenId",
+                      "nodeType": "Identifier",
+                      "overloadedDeclarations": [],
+                      "referencedDeclaration": 1254,
+                      "src": "32534:7:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_uint256",
+                        "typeString": "uint256"
+                      }
+                    },
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+                    "isLValue": true,
+                    "isPure": false,
+                    "lValueRequested": false,
+                    "nodeType": "IndexAccess",
+                    "src": "32518:24:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_uint256",
+                      "typeString": "uint256"
+                    }
+                  },
+                  "nodeType": "VariableDeclarationStatement",
+                  "src": "32497:45:1"
+                },
+                {
+                  "assignments": [
+                    1272
+                  ],
+                  "declarations": [
+                    {
+                      "constant": false,
+                      "id": 1272,
+                      "name": "lastTokenId",
+                      "nodeType": "VariableDeclaration",
+                      "scope": 1300,
+                      "src": "32864:19:1",
+                      "stateVariable": false,
+                      "storageLocation": "default",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_uint256",
+                        "typeString": "uint256"
+                      },
+                      "typeName": {
+                        "id": 1271,
+                        "name": "uint256",
+                        "nodeType": "ElementaryTypeName",
+                        "src": "32864:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      },
+                      "value": null,
+                      "visibility": "internal"
+                    }
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+                    "baseExpression": {
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+                      "name": "_allTokens",
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+                      "src": "32886:10:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_array$_t_uint256_$dyn_storage",
+                        "typeString": "uint256[] storage ref"
+                      }
+                    },
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+                    "indexExpression": {
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+                      "id": 1274,
+                      "name": "lastTokenIndex",
+                      "nodeType": "Identifier",
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+                      "src": "32897:14:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_uint256",
+                        "typeString": "uint256"
+                      }
+                    },
+                    "isConstant": false,
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+                    "isPure": false,
+                    "lValueRequested": false,
+                    "nodeType": "IndexAccess",
+                    "src": "32886:26:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_uint256",
+                      "typeString": "uint256"
+                    }
+                  },
+                  "nodeType": "VariableDeclarationStatement",
+                  "src": "32864:48:1"
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+                        "name": "_allTokens",
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+                        "src": "32923:10:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_array$_t_uint256_$dyn_storage",
+                          "typeString": "uint256[] storage ref"
+                        }
+                      },
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+                      "indexExpression": {
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+                        "name": "tokenIndex",
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+                        "src": "32934:10:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
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+                        "typeIdentifier": "t_uint256",
+                        "typeString": "uint256"
+                      }
+                    },
+                    "nodeType": "Assignment",
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+                      "name": "lastTokenId",
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+                      "src": "32948:11:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_uint256",
+                        "typeString": "uint256"
+                      }
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+                    "src": "32923:36:1",
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+                    }
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+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 992,
+                        "src": "33027:15:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_mapping$_t_uint256_$_t_uint256_$",
+                          "typeString": "mapping(uint256 => uint256)"
+                        }
+                      },
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+                        "name": "lastTokenId",
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+                        "src": "33043:11:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
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+                        "src": "33189:10:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_array$_t_uint256_$dyn_storage",
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+                        "referencedDeclaration": 882,
+                        "src": "23642:4:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        }
+                      },
+                      {
+                        "argumentTypes": null,
+                        "id": 910,
+                        "name": "tokenId",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 886,
+                        "src": "23648:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      },
+                      {
+                        "argumentTypes": null,
+                        "id": 911,
+                        "name": "_data",
+                        "nodeType": "Identifier",
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+                        "referencedDeclaration": 888,
+                        "src": "23657:5:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_bytes_memory_ptr",
+                          "typeString": "bytes memory"
+                        }
+                      }
+                    ],
+                    "expression": {
+                      "argumentTypes": [
+                        {
+                          "typeIdentifier": "t_address_payable",
+                          "typeString": "address payable"
+                        },
+                        {
+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        },
+                        {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        },
+                        {
+                          "typeIdentifier": "t_bytes_memory_ptr",
+                          "typeString": "bytes memory"
+                        }
+                      ],
+                      "expression": {
+                        "argumentTypes": null,
+                        "arguments": [
+                          {
+                            "argumentTypes": null,
+                            "id": 904,
+                            "name": "to",
+                            "nodeType": "Identifier",
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+                            "referencedDeclaration": 884,
+                            "src": "23609:2:1",
+                            "typeDescriptions": {
+                              "typeIdentifier": "t_address",
+                              "typeString": "address"
+                            }
+                          }
+                        ],
+                        "expression": {
+                          "argumentTypes": [
+                            {
+                              "typeIdentifier": "t_address",
+                              "typeString": "address"
+                            }
+                          ],
+                          "id": 903,
+                          "name": "IERC721Receiver",
+                          "nodeType": "Identifier",
+                          "overloadedDeclarations": [],
+                          "referencedDeclaration": 139,
+                          "src": "23593:15:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_type$_t_contract$_IERC721Receiver_$139_$",
+                            "typeString": "type(contract IERC721Receiver)"
+                          }
+                        },
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+                        "isLValue": false,
+                        "isPure": false,
+                        "kind": "typeConversion",
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+                        "names": [],
+                        "nodeType": "FunctionCall",
+                        "src": "23593:19:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_contract$_IERC721Receiver_$139",
+                          "typeString": "contract IERC721Receiver"
+                        }
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+                      "isLValue": false,
+                      "isPure": false,
+                      "lValueRequested": false,
+                      "memberName": "onERC721Received",
+                      "nodeType": "MemberAccess",
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+                      "src": "23593:36:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_function_external_nonpayable$_t_address_$_t_address_$_t_uint256_$_t_bytes_memory_ptr_$returns$_t_bytes4_$",
+                        "typeString": "function (address,address,uint256,bytes memory) external returns (bytes4)"
+                      }
+                    },
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+                    "isConstant": false,
+                    "isLValue": false,
+                    "isPure": false,
+                    "kind": "functionCall",
+                    "lValueRequested": false,
+                    "names": [],
+                    "nodeType": "FunctionCall",
+                    "src": "23593:70:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_bytes4",
+                      "typeString": "bytes4"
+                    }
+                  },
+                  "nodeType": "VariableDeclarationStatement",
+                  "src": "23577:86:1"
+                },
+                {
+                  "expression": {
+                    "argumentTypes": null,
+                    "components": [
+                      {
+                        "argumentTypes": null,
+                        "commonType": {
+                          "typeIdentifier": "t_bytes4",
+                          "typeString": "bytes4"
+                        },
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+                        "isPure": false,
+                        "lValueRequested": false,
+                        "leftExpression": {
+                          "argumentTypes": null,
+                          "id": 914,
+                          "name": "retval",
+                          "nodeType": "Identifier",
+                          "overloadedDeclarations": [],
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+                          "src": "23681:6:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_bytes4",
+                            "typeString": "bytes4"
+                          }
+                        },
+                        "nodeType": "BinaryOperation",
+                        "operator": "==",
+                        "rightExpression": {
+                          "argumentTypes": null,
+                          "id": 915,
+                          "name": "_ERC721_RECEIVED",
+                          "nodeType": "Identifier",
+                          "overloadedDeclarations": [],
+                          "referencedDeclaration": 403,
+                          "src": "23691:16:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_bytes4",
+                            "typeString": "bytes4"
+                          }
+                        },
+                        "src": "23681:26:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_bool",
+                          "typeString": "bool"
+                        }
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+                  "nodeType": "Return",
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+                }
+              ]
+            },
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+                  "visibility": "internal"
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+                    "src": "23426:7:1",
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+                      "typeIdentifier": "t_uint256",
+                      "typeString": "uint256"
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+                  "value": null,
+                  "visibility": "internal"
+                },
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+                  "src": "23443:18:1",
+                  "stateVariable": false,
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+                    "name": "bytes",
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+                    "src": "23443:5:1",
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+                      "typeIdentifier": "t_bytes_storage_ptr",
+                      "typeString": "bytes"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                }
+              ],
+              "src": "23399:63:1"
+            },
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+              "nodeType": "ParameterList",
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+                  "id": 891,
+                  "name": "",
+                  "nodeType": "VariableDeclaration",
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+                  "src": "23489:4:1",
+                  "stateVariable": false,
+                  "storageLocation": "default",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_bool",
+                    "typeString": "bool"
+                  },
+                  "typeName": {
+                    "id": 890,
+                    "name": "bool",
+                    "nodeType": "ElementaryTypeName",
+                    "src": "23489:4:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_bool",
+                      "typeString": "bool"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                }
+              ],
+              "src": "23488:6:1"
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+            "src": "23368:347:1",
+            "stateMutability": "nonpayable",
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+              "nodeType": "Block",
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+                    "commonType": {
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+                      "baseExpression": {
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+                        "id": 925,
+                        "name": "_tokenApprovals",
+                        "nodeType": "Identifier",
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+                        "referencedDeclaration": 411,
+                        "src": "23940:15:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_mapping$_t_uint256_$_t_address_$",
+                          "typeString": "mapping(uint256 => address)"
+                        }
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+                        "id": 926,
+                        "name": "tokenId",
+                        "nodeType": "Identifier",
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+                        "referencedDeclaration": 922,
+                        "src": "23956:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
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+                        "typeString": "address"
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+                    },
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+                      "arguments": [
+                        {
+                          "argumentTypes": null,
+                          "hexValue": "30",
+                          "id": 929,
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+                          "isLValue": false,
+                          "isPure": true,
+                          "kind": "number",
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+                          "nodeType": "Literal",
+                          "src": "23976:1:1",
+                          "subdenomination": null,
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_rational_0_by_1",
+                            "typeString": "int_const 0"
+                          },
+                          "value": "0"
+                        }
+                      ],
+                      "expression": {
+                        "argumentTypes": [
+                          {
+                            "typeIdentifier": "t_rational_0_by_1",
+                            "typeString": "int_const 0"
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+                        "isConstant": false,
+                        "isLValue": false,
+                        "isPure": true,
+                        "lValueRequested": false,
+                        "nodeType": "ElementaryTypeNameExpression",
+                        "src": "23968:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_type$_t_address_$",
+                          "typeString": "type(address)"
+                        },
+                        "typeName": "address"
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+                      "isPure": true,
+                      "kind": "typeConversion",
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+                      "names": [],
+                      "nodeType": "FunctionCall",
+                      "src": "23968:10:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_address_payable",
+                        "typeString": "address payable"
+                      }
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+                    "src": "23940:38:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_bool",
+                      "typeString": "bool"
+                    }
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+                  "nodeType": "IfStatement",
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+                    "nodeType": "Block",
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+                          "id": 938,
+                          "isConstant": false,
+                          "isLValue": false,
+                          "isPure": false,
+                          "lValueRequested": false,
+                          "leftHandSide": {
+                            "argumentTypes": null,
+                            "baseExpression": {
+                              "argumentTypes": null,
+                              "id": 932,
+                              "name": "_tokenApprovals",
+                              "nodeType": "Identifier",
+                              "overloadedDeclarations": [],
+                              "referencedDeclaration": 411,
+                              "src": "23994:15:1",
+                              "typeDescriptions": {
+                                "typeIdentifier": "t_mapping$_t_uint256_$_t_address_$",
+                                "typeString": "mapping(uint256 => address)"
+                              }
+                            },
+                            "id": 934,
+                            "indexExpression": {
+                              "argumentTypes": null,
+                              "id": 933,
+                              "name": "tokenId",
+                              "nodeType": "Identifier",
+                              "overloadedDeclarations": [],
+                              "referencedDeclaration": 922,
+                              "src": "24010:7:1",
+                              "typeDescriptions": {
+                                "typeIdentifier": "t_uint256",
+                                "typeString": "uint256"
+                              }
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+                            "isConstant": false,
+                            "isLValue": true,
+                            "isPure": false,
+                            "lValueRequested": true,
+                            "nodeType": "IndexAccess",
+                            "src": "23994:24:1",
+                            "typeDescriptions": {
+                              "typeIdentifier": "t_address",
+                              "typeString": "address"
+                            }
+                          },
+                          "nodeType": "Assignment",
+                          "operator": "=",
+                          "rightHandSide": {
+                            "argumentTypes": null,
+                            "arguments": [
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+                                "argumentTypes": null,
+                                "hexValue": "30",
+                                "id": 936,
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+                                "isLValue": false,
+                                "isPure": true,
+                                "kind": "number",
+                                "lValueRequested": false,
+                                "nodeType": "Literal",
+                                "src": "24029:1:1",
+                                "subdenomination": null,
+                                "typeDescriptions": {
+                                  "typeIdentifier": "t_rational_0_by_1",
+                                  "typeString": "int_const 0"
+                                },
+                                "value": "0"
+                              }
+                            ],
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+                              "argumentTypes": [
+                                {
+                                  "typeIdentifier": "t_rational_0_by_1",
+                                  "typeString": "int_const 0"
+                                }
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+                              "isConstant": false,
+                              "isLValue": false,
+                              "isPure": true,
+                              "lValueRequested": false,
+                              "nodeType": "ElementaryTypeNameExpression",
+                              "src": "24021:7:1",
+                              "typeDescriptions": {
+                                "typeIdentifier": "t_type$_t_address_$",
+                                "typeString": "type(address)"
+                              },
+                              "typeName": "address"
+                            },
+                            "id": 937,
+                            "isConstant": false,
+                            "isLValue": false,
+                            "isPure": true,
+                            "kind": "typeConversion",
+                            "lValueRequested": false,
+                            "names": [],
+                            "nodeType": "FunctionCall",
+                            "src": "24021:10:1",
+                            "typeDescriptions": {
+                              "typeIdentifier": "t_address_payable",
+                              "typeString": "address payable"
+                            }
+                          },
+                          "src": "23994:37:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_address",
+                            "typeString": "address"
+                          }
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+                        "id": 939,
+                        "nodeType": "ExpressionStatement",
+                        "src": "23994:37:1"
+                      }
+                    ]
+                  }
+                }
+              ]
+            },
+            "documentation": "@dev Private function to clear current approval of a given token ID.\n@param tokenId uint256 ID of the token to be transferred",
+            "id": 943,
+            "implemented": true,
+            "kind": "function",
+            "modifiers": [],
+            "name": "_clearApproval",
+            "nodeType": "FunctionDefinition",
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+              "nodeType": "ParameterList",
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+                  "nodeType": "VariableDeclaration",
+                  "scope": 943,
+                  "src": "23901:15:1",
+                  "stateVariable": false,
+                  "storageLocation": "default",
+                  "typeDescriptions": {
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+                    "name": "uint256",
+                    "nodeType": "ElementaryTypeName",
+                    "src": "23901:7:1",
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+                      "typeString": "uint256"
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+                  "visibility": "internal"
+                }
+              ],
+              "src": "23900:17:1"
+            },
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+              "src": "23926:0:1"
+            },
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+            "src": "23877:171:1",
+            "stateMutability": "nonpayable",
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+            "visibility": "private"
+          }
+        ],
+        "scope": 1469,
+        "src": "11949:12101:1"
+      },
+      {
+        "id": 945,
+        "literals": [
+          "solidity",
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+          ".0"
+        ],
+        "nodeType": "PragmaDirective",
+        "src": "24121:23:1"
+      },
+      {
+        "baseContracts": [
+          {
+            "arguments": null,
+            "baseName": {
+              "contractScope": null,
+              "id": 946,
+              "name": "IERC721",
+              "nodeType": "UserDefinedTypeName",
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+              "src": "24314:7:1",
+              "typeDescriptions": {
+                "typeIdentifier": "t_contract$_IERC721_$124",
+                "typeString": "contract IERC721"
+              }
+            },
+            "id": 947,
+            "nodeType": "InheritanceSpecifier",
+            "src": "24314:7:1"
+          }
+        ],
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+        ],
+        "contractKind": "contract",
+        "documentation": "@title ERC-721 Non-Fungible Token Standard, optional enumeration extension\n@dev See https://eips.ethereum.org/EIPS/eip-721",
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+        "id": 969,
+        "linearizedBaseContracts": [
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+          23
+        ],
+        "name": "IERC721Enumerable",
+        "nodeType": "ContractDefinition",
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+            "documentation": null,
+            "id": 952,
+            "implemented": false,
+            "kind": "function",
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+            "name": "totalSupply",
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+                          "typeIdentifier": "t_mapping$_t_address_$_t_array$_t_uint256_$dyn_storage_$",
+                          "typeString": "mapping(address => uint256[] storage ref)"
+                        }
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+                        "name": "owner",
+                        "nodeType": "Identifier",
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+                        "src": "26489:5:1",
+                        "typeDescriptions": {
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+                          "typeString": "address"
+                        }
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+                      "nodeType": "IndexAccess",
+                      "src": "26476:19:1",
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+                        "typeString": "uint256[] storage ref"
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+                      "id": 1024,
+                      "name": "index",
+                      "nodeType": "Identifier",
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+                      "src": "26496:5:1",
+                      "typeDescriptions": {
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+                  "storageLocation": "default",
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+                    "typeString": "address"
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+                    "name": "address",
+                    "nodeType": "ElementaryTypeName",
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+                    "stateMutability": "nonpayable",
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+                      "typeString": "address"
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+                      "name": "_allTokens",
+                      "nodeType": "Identifier",
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+                      "src": "26732:10:1",
+                      "typeDescriptions": {
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+                    "memberName": "length",
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+                    "src": "26732:17:1",
+                    "typeDescriptions": {
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+                      "typeString": "uint256"
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+                  "nodeType": "Return",
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+                }
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+            },
+            "documentation": "@dev Gets the total amount of tokens stored by the contract.\n@return uint256 representing the total amount of tokens",
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+            "implemented": true,
+            "kind": "function",
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+            "name": "totalSupply",
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+                  "storageLocation": "default",
+                  "typeDescriptions": {
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+                    "typeString": "uint256"
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+                    "name": "uint256",
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+                      "typeString": "uint256"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                }
+              ],
+              "src": "26705:9:1"
+            },
+            "scope": 1302,
+            "src": "26662:94:1",
+            "stateMutability": "view",
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+            "visibility": "public"
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+                        "commonType": {
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+                          "typeString": "uint256"
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+                        "isLValue": false,
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+                        "lValueRequested": false,
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+                          "id": 1045,
+                          "name": "index",
+                          "nodeType": "Identifier",
+                          "overloadedDeclarations": [],
+                          "referencedDeclaration": 1039,
+                          "src": "27179:5:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_uint256",
+                            "typeString": "uint256"
+                          }
+                        },
+                        "nodeType": "BinaryOperation",
+                        "operator": "<",
+                        "rightExpression": {
+                          "argumentTypes": null,
+                          "arguments": [],
+                          "expression": {
+                            "argumentTypes": [],
+                            "id": 1046,
+                            "name": "totalSupply",
+                            "nodeType": "Identifier",
+                            "overloadedDeclarations": [
+                              1037
+                            ],
+                            "referencedDeclaration": 1037,
+                            "src": "27187:11:1",
+                            "typeDescriptions": {
+                              "typeIdentifier": "t_function_internal_view$__$returns$_t_uint256_$",
+                              "typeString": "function () view returns (uint256)"
+                            }
+                          },
+                          "id": 1047,
+                          "isConstant": false,
+                          "isLValue": false,
+                          "isPure": false,
+                          "kind": "functionCall",
+                          "lValueRequested": false,
+                          "names": [],
+                          "nodeType": "FunctionCall",
+                          "src": "27187:13:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_uint256",
+                            "typeString": "uint256"
+                          }
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+                        "src": "27179:21:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_bool",
+                          "typeString": "bool"
+                        }
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+                        "isConstant": false,
+                        "isLValue": false,
+                        "isPure": true,
+                        "kind": "string",
+                        "lValueRequested": false,
+                        "nodeType": "Literal",
+                        "src": "27202:46:1",
+                        "subdenomination": null,
+                        "typeDescriptions": {
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+                          "typeString": "literal_string \"ERC721Enumerable: global index out of bounds\""
+                        },
+                        "value": "ERC721Enumerable: global index out of bounds"
+                      }
+                    ],
+                    "expression": {
+                      "argumentTypes": [
+                        {
+                          "typeIdentifier": "t_bool",
+                          "typeString": "bool"
+                        },
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+                        1544
+                      ],
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+                      "src": "27171:7:1",
+                      "typeDescriptions": {
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+                        "typeString": "function (bool,string memory) pure"
+                      }
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+                    "id": 1050,
+                    "isConstant": false,
+                    "isLValue": false,
+                    "isPure": false,
+                    "kind": "functionCall",
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+                      "typeString": "tuple()"
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+                      "id": 1052,
+                      "name": "_allTokens",
+                      "nodeType": "Identifier",
+                      "overloadedDeclarations": [],
+                      "referencedDeclaration": 988,
+                      "src": "27266:10:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_array$_t_uint256_$dyn_storage",
+                        "typeString": "uint256[] storage ref"
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+                    "id": 1054,
+                    "indexExpression": {
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+                      "id": 1053,
+                      "name": "index",
+                      "nodeType": "Identifier",
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+                      "referencedDeclaration": 1039,
+                      "src": "27277:5:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_uint256",
+                        "typeString": "uint256"
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+                    "lValueRequested": false,
+                    "nodeType": "IndexAccess",
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+                      "typeString": "uint256"
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+                  "src": "27259:24:1"
+                }
+              ]
+            },
+            "documentation": "@dev Gets the token ID at a given index of all the tokens in this contract\nReverts if the index is greater or equal to the total number of tokens.\n@param index uint256 representing the index to be accessed of the tokens list\n@return uint256 token ID at the given index of the tokens list",
+            "id": 1057,
+            "implemented": true,
+            "kind": "function",
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+                  "name": "index",
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+                  "stateVariable": false,
+                  "storageLocation": "default",
+                  "typeDescriptions": {
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+                    "typeString": "uint256"
+                  },
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+                    "name": "uint256",
+                    "nodeType": "ElementaryTypeName",
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+                    "typeDescriptions": {
+                      "typeIdentifier": "t_uint256",
+                      "typeString": "uint256"
+                    }
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+                  "value": null,
+                  "visibility": "internal"
+                }
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+                  "nodeType": "VariableDeclaration",
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+                  "src": "27152:7:1",
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+                  "storageLocation": "default",
+                  "typeDescriptions": {
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+                    "typeString": "uint256"
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+                        "name": "from",
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+                        "src": "27770:4:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        }
+                      },
+                      {
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+                        "id": 1070,
+                        "name": "to",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 1061,
+                        "src": "27776:2:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        }
+                      },
+                      {
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+                        "id": 1071,
+                        "name": "tokenId",
+                        "nodeType": "Identifier",
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+                        "referencedDeclaration": 1063,
+                        "src": "27780:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      }
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+                      "argumentTypes": [
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+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
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+                        {
+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        },
+                        {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
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+                        "name": "super",
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+                        "src": "27750:5:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_super$_ERC721Enumerable_$1302",
+                          "typeString": "contract super ERC721Enumerable"
+                        }
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+                        "name": "from",
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+                        "src": "27832:4:1",
+                        "typeDescriptions": {
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+                          "typeString": "address"
+                        }
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+                      {
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+                        "id": 1076,
+                        "name": "tokenId",
+                        "nodeType": "Identifier",
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+                        "referencedDeclaration": 1063,
+                        "src": "27838:7:1",
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+                          "typeString": "uint256"
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+                          "typeString": "address"
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+                        {
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+                          "typeString": "uint256"
+                        }
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+                        "referencedDeclaration": 1061,
+                        "src": "27885:2:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        }
+                      },
+                      {
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+                        "id": 1081,
+                        "name": "tokenId",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 1063,
+                        "src": "27889:7:1",
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+                          "typeString": "address"
+                        },
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+                          "typeString": "uint256"
+                        }
+                      ],
+                      "id": 1079,
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+                      "nodeType": "Identifier",
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+                      "src": "27857:27:1",
+                      "typeDescriptions": {
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+                        "typeString": "function (address,uint256)"
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+                }
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+                  "storageLocation": "default",
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+                    "typeIdentifier": "t_address",
+                    "typeString": "address"
+                  },
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+                    "name": "address",
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+                    "src": "27688:7:1",
+                    "stateMutability": "nonpayable",
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+                      "typeIdentifier": "t_address",
+                      "typeString": "address"
+                    }
+                  },
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+                  "visibility": "internal"
+                },
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+                  "constant": false,
+                  "id": 1061,
+                  "name": "to",
+                  "nodeType": "VariableDeclaration",
+                  "scope": 1085,
+                  "src": "27702:10:1",
+                  "stateVariable": false,
+                  "storageLocation": "default",
+                  "typeDescriptions": {
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+                    "typeString": "address"
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+                    "name": "address",
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+                    "src": "27702:7:1",
+                    "stateMutability": "nonpayable",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_address",
+                      "typeString": "address"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                },
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+                  "constant": false,
+                  "id": 1063,
+                  "name": "tokenId",
+                  "nodeType": "VariableDeclaration",
+                  "scope": 1085,
+                  "src": "27714:15:1",
+                  "stateVariable": false,
+                  "storageLocation": "default",
+                  "typeDescriptions": {
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+                    "typeString": "uint256"
+                  },
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+                    "id": 1062,
+                    "name": "uint256",
+                    "nodeType": "ElementaryTypeName",
+                    "src": "27714:7:1",
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+                      "typeIdentifier": "t_uint256",
+                      "typeString": "uint256"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                }
+              ],
+              "src": "27687:43:1"
+            },
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+              "nodeType": "ParameterList",
+              "parameters": [],
+              "src": "27740:0:1"
+            },
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+            "src": "27665:239:1",
+            "stateMutability": "nonpayable",
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+            "visibility": "internal"
+          },
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+              "nodeType": "Block",
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+                        "referencedDeclaration": 1087,
+                        "src": "28236:2:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        }
+                      },
+                      {
+                        "argumentTypes": null,
+                        "id": 1096,
+                        "name": "tokenId",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 1089,
+                        "src": "28240:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      }
+                    ],
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+                      "argumentTypes": [
+                        {
+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        },
+                        {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      ],
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+                        "id": 1092,
+                        "name": "super",
+                        "nodeType": "Identifier",
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+                        "referencedDeclaration": 1572,
+                        "src": "28224:5:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_super$_ERC721Enumerable_$1302",
+                          "typeString": "contract super ERC721Enumerable"
+                        }
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+                      "isConstant": false,
+                      "isLValue": false,
+                      "isPure": false,
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+                      "memberName": "_mint",
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+                      "src": "28224:11:1",
+                      "typeDescriptions": {
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+                        "typeString": "function (address,uint256)"
+                      }
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+                    "isLValue": false,
+                    "isPure": false,
+                    "kind": "functionCall",
+                    "lValueRequested": false,
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+                    "src": "28224:24:1",
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+                      "typeString": "tuple()"
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+                        "id": 1100,
+                        "name": "to",
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+                        "referencedDeclaration": 1087,
+                        "src": "28287:2:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        }
+                      },
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+                        "argumentTypes": null,
+                        "id": 1101,
+                        "name": "tokenId",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 1089,
+                        "src": "28291:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
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+                    ],
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+                        {
+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        },
+                        {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      ],
+                      "id": 1099,
+                      "name": "_addTokenToOwnerEnumeration",
+                      "nodeType": "Identifier",
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+                      "src": "28259:27:1",
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+                        "typeString": "function (address,uint256)"
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+                    "src": "28259:40:1",
+                    "typeDescriptions": {
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+                      "typeString": "tuple()"
+                    }
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+                  "src": "28259:40:1"
+                },
+                {
+                  "expression": {
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+                    "arguments": [
+                      {
+                        "argumentTypes": null,
+                        "id": 1105,
+                        "name": "tokenId",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 1089,
+                        "src": "28342:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      }
+                    ],
+                    "expression": {
+                      "argumentTypes": [
+                        {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      ],
+                      "id": 1104,
+                      "name": "_addTokenToAllTokensEnumeration",
+                      "nodeType": "Identifier",
+                      "overloadedDeclarations": [],
+                      "referencedDeclaration": 1195,
+                      "src": "28310:31:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_function_internal_nonpayable$_t_uint256_$returns$__$",
+                        "typeString": "function (uint256)"
+                      }
+                    },
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+                    "isConstant": false,
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+                    "isPure": false,
+                    "kind": "functionCall",
+                    "lValueRequested": false,
+                    "names": [],
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+                    "src": "28310:40:1",
+                    "typeDescriptions": {
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+                      "typeString": "tuple()"
+                    }
+                  },
+                  "id": 1107,
+                  "nodeType": "ExpressionStatement",
+                  "src": "28310:40:1"
+                }
+              ]
+            },
+            "documentation": "@dev Internal function to mint a new token.\nReverts if the given token ID already exists.\n@param to address the beneficiary that will own the minted token\n@param tokenId uint256 ID of the token to be minted",
+            "id": 1109,
+            "implemented": true,
+            "kind": "function",
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+            "name": "_mint",
+            "nodeType": "FunctionDefinition",
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+              "nodeType": "ParameterList",
+              "parameters": [
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+                  "id": 1087,
+                  "name": "to",
+                  "nodeType": "VariableDeclaration",
+                  "scope": 1109,
+                  "src": "28176:10:1",
+                  "stateVariable": false,
+                  "storageLocation": "default",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_address",
+                    "typeString": "address"
+                  },
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+                    "name": "address",
+                    "nodeType": "ElementaryTypeName",
+                    "src": "28176:7:1",
+                    "stateMutability": "nonpayable",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_address",
+                      "typeString": "address"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                },
+                {
+                  "constant": false,
+                  "id": 1089,
+                  "name": "tokenId",
+                  "nodeType": "VariableDeclaration",
+                  "scope": 1109,
+                  "src": "28188:15:1",
+                  "stateVariable": false,
+                  "storageLocation": "default",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_uint256",
+                    "typeString": "uint256"
+                  },
+                  "typeName": {
+                    "id": 1088,
+                    "name": "uint256",
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+                    "src": "28188:7:1",
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+                      "typeString": "uint256"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                }
+              ],
+              "src": "28175:29:1"
+            },
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+              "nodeType": "ParameterList",
+              "parameters": [],
+              "src": "28214:0:1"
+            },
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+            "src": "28161:196:1",
+            "stateMutability": "nonpayable",
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+            "visibility": "internal"
+          },
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+              "src": "28688:308:1",
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+                    "arguments": [
+                      {
+                        "argumentTypes": null,
+                        "id": 1119,
+                        "name": "owner",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 1111,
+                        "src": "28710:5:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        }
+                      },
+                      {
+                        "argumentTypes": null,
+                        "id": 1120,
+                        "name": "tokenId",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 1113,
+                        "src": "28717:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      }
+                    ],
+                    "expression": {
+                      "argumentTypes": [
+                        {
+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        },
+                        {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      ],
+                      "expression": {
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+                        "id": 1116,
+                        "name": "super",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 1572,
+                        "src": "28698:5:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_super$_ERC721Enumerable_$1302",
+                          "typeString": "contract super ERC721Enumerable"
+                        }
+                      },
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+                      "isConstant": false,
+                      "isLValue": false,
+                      "isPure": false,
+                      "lValueRequested": false,
+                      "memberName": "_burn",
+                      "nodeType": "MemberAccess",
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+                      "src": "28698:11:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_function_internal_nonpayable$_t_address_$_t_uint256_$returns$__$",
+                        "typeString": "function (address,uint256)"
+                      }
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+                    "isLValue": false,
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+                    "kind": "functionCall",
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+                      "typeString": "tuple()"
+                    }
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+                  "src": "28698:27:1"
+                },
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+                    "arguments": [
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+                        "argumentTypes": null,
+                        "id": 1124,
+                        "name": "owner",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 1111,
+                        "src": "28769:5:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        }
+                      },
+                      {
+                        "argumentTypes": null,
+                        "id": 1125,
+                        "name": "tokenId",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 1113,
+                        "src": "28776:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      }
+                    ],
+                    "expression": {
+                      "argumentTypes": [
+                        {
+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        },
+                        {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      ],
+                      "id": 1123,
+                      "name": "_removeTokenFromOwnerEnumeration",
+                      "nodeType": "Identifier",
+                      "overloadedDeclarations": [],
+                      "referencedDeclaration": 1252,
+                      "src": "28736:32:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_function_internal_nonpayable$_t_address_$_t_uint256_$returns$__$",
+                        "typeString": "function (address,uint256)"
+                      }
+                    },
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+                    "isConstant": false,
+                    "isLValue": false,
+                    "isPure": false,
+                    "kind": "functionCall",
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+                    "src": "28736:48:1",
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+                      "typeString": "tuple()"
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+                  "nodeType": "ExpressionStatement",
+                  "src": "28736:48:1"
+                },
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+                    "id": 1132,
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+                    "isLValue": false,
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+                    "lValueRequested": false,
+                    "leftHandSide": {
+                      "argumentTypes": null,
+                      "baseExpression": {
+                        "argumentTypes": null,
+                        "id": 1128,
+                        "name": "_ownedTokensIndex",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 985,
+                        "src": "28903:17:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_mapping$_t_uint256_$_t_uint256_$",
+                          "typeString": "mapping(uint256 => uint256)"
+                        }
+                      },
+                      "id": 1130,
+                      "indexExpression": {
+                        "argumentTypes": null,
+                        "id": 1129,
+                        "name": "tokenId",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 1113,
+                        "src": "28921:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      },
+                      "isConstant": false,
+                      "isLValue": true,
+                      "isPure": false,
+                      "lValueRequested": true,
+                      "nodeType": "IndexAccess",
+                      "src": "28903:26:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_uint256",
+                        "typeString": "uint256"
+                      }
+                    },
+                    "nodeType": "Assignment",
+                    "operator": "=",
+                    "rightHandSide": {
+                      "argumentTypes": null,
+                      "hexValue": "30",
+                      "id": 1131,
+                      "isConstant": false,
+                      "isLValue": false,
+                      "isPure": true,
+                      "kind": "number",
+                      "lValueRequested": false,
+                      "nodeType": "Literal",
+                      "src": "28932:1:1",
+                      "subdenomination": null,
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_rational_0_by_1",
+                        "typeString": "int_const 0"
+                      },
+                      "value": "0"
+                    },
+                    "src": "28903:30:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_uint256",
+                      "typeString": "uint256"
+                    }
+                  },
+                  "id": 1133,
+                  "nodeType": "ExpressionStatement",
+                  "src": "28903:30:1"
+                },
+                {
+                  "expression": {
+                    "argumentTypes": null,
+                    "arguments": [
+                      {
+                        "argumentTypes": null,
+                        "id": 1135,
+                        "name": "tokenId",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 1113,
+                        "src": "28981:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      }
+                    ],
+                    "expression": {
+                      "argumentTypes": [
+                        {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      ],
+                      "id": 1134,
+                      "name": "_removeTokenFromAllTokensEnumeration",
+                      "nodeType": "Identifier",
+                      "overloadedDeclarations": [],
+                      "referencedDeclaration": 1301,
+                      "src": "28944:36:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_function_internal_nonpayable$_t_uint256_$returns$__$",
+                        "typeString": "function (uint256)"
+                      }
+                    },
+                    "id": 1136,
+                    "isConstant": false,
+                    "isLValue": false,
+                    "isPure": false,
+                    "kind": "functionCall",
+                    "lValueRequested": false,
+                    "names": [],
+                    "nodeType": "FunctionCall",
+                    "src": "28944:45:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_tuple$__$",
+                      "typeString": "tuple()"
+                    }
+                  },
+                  "id": 1137,
+                  "nodeType": "ExpressionStatement",
+                  "src": "28944:45:1"
+                }
+              ]
+            },
+            "documentation": "@dev Internal function to burn a specific token.\nReverts if the token does not exist.\nDeprecated, use _burn(uint256) instead.\n@param owner owner of the token to burn\n@param tokenId uint256 ID of the token being burned",
+            "id": 1139,
+            "implemented": true,
+            "kind": "function",
+            "modifiers": [],
+            "name": "_burn",
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+              "parameters": [
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+                  "constant": false,
+                  "id": 1111,
+                  "name": "owner",
+                  "nodeType": "VariableDeclaration",
+                  "scope": 1139,
+                  "src": "28647:13:1",
+                  "stateVariable": false,
+                  "storageLocation": "default",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_address",
+                    "typeString": "address"
+                  },
+                  "typeName": {
+                    "id": 1110,
+                    "name": "address",
+                    "nodeType": "ElementaryTypeName",
+                    "src": "28647:7:1",
+                    "stateMutability": "nonpayable",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_address",
+                      "typeString": "address"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                },
+                {
+                  "constant": false,
+                  "id": 1113,
+                  "name": "tokenId",
+                  "nodeType": "VariableDeclaration",
+                  "scope": 1139,
+                  "src": "28662:15:1",
+                  "stateVariable": false,
+                  "storageLocation": "default",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_uint256",
+                    "typeString": "uint256"
+                  },
+                  "typeName": {
+                    "id": 1112,
+                    "name": "uint256",
+                    "nodeType": "ElementaryTypeName",
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+                            "typeDescriptions": {
+                              "typeIdentifier": "t_mapping$_t_address_$_t_array$_t_uint256_$dyn_storage_$",
+                              "typeString": "mapping(address => uint256[] storage ref)"
+                            }
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+                            "referencedDeclaration": 1197,
+                            "src": "31073:4:1",
+                            "typeDescriptions": {
+                              "typeIdentifier": "t_address",
+                              "typeString": "address"
+                            }
+                          },
+                          "isConstant": false,
+                          "isLValue": true,
+                          "isPure": false,
+                          "lValueRequested": false,
+                          "nodeType": "IndexAccess",
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+                            "typeIdentifier": "t_array$_t_uint256_$dyn_storage",
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+                          }
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+                        "memberName": "length",
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+                        "src": "31060:25:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      },
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+                      "memberName": "sub",
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+                      "src": "31060:29:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_function_internal_pure$_t_uint256_$_t_uint256_$returns$_t_uint256_$bound_to$_t_uint256_$",
+                        "typeString": "function (uint256,uint256) pure returns (uint256)"
+                      }
+                    },
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+                    "isConstant": false,
+                    "isLValue": false,
+                    "isPure": false,
+                    "kind": "functionCall",
+                    "lValueRequested": false,
+                    "names": [],
+                    "nodeType": "FunctionCall",
+                    "src": "31060:32:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_uint256",
+                      "typeString": "uint256"
+                    }
+                  },
+                  "nodeType": "VariableDeclarationStatement",
+                  "src": "31035:57:1"
+                },
+                {
+                  "assignments": [
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+                  ],
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+                      "stateVariable": false,
+                      "storageLocation": "default",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_uint256",
+                        "typeString": "uint256"
+                      },
+                      "typeName": {
+                        "id": 1212,
+                        "name": "uint256",
+                        "nodeType": "ElementaryTypeName",
+                        "src": "31102:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      },
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+                    }
+                  ],
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+                      "src": "31123:17:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_mapping$_t_uint256_$_t_uint256_$",
+                        "typeString": "mapping(uint256 => uint256)"
+                      }
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+                        "typeIdentifier": "t_uint256",
+                        "typeString": "uint256"
+                      }
+                    },
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+                    "nodeType": "IndexAccess",
+                    "src": "31123:26:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_uint256",
+                      "typeString": "uint256"
+                    }
+                  },
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+                },
+                {
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+                    },
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+                      "src": "31253:10:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_uint256",
+                        "typeString": "uint256"
+                      }
+                    },
+                    "nodeType": "BinaryOperation",
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+                      "name": "lastTokenIndex",
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+                      "referencedDeclaration": 1203,
+                      "src": "31267:14:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_uint256",
+                        "typeString": "uint256"
+                      }
+                    },
+                    "src": "31253:28:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_bool",
+                      "typeString": "bool"
+                    }
+                  },
+                  "falseBody": null,
+                  "id": 1244,
+                  "nodeType": "IfStatement",
+                  "src": "31249:323:1",
+                  "trueBody": {
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+                    "nodeType": "Block",
+                    "src": "31283:289:1",
+                    "statements": [
+                      {
+                        "assignments": [
+                          1222
+                        ],
+                        "declarations": [
+                          {
+                            "constant": false,
+                            "id": 1222,
+                            "name": "lastTokenId",
+                            "nodeType": "VariableDeclaration",
+                            "scope": 1243,
+                            "src": "31297:19:1",
+                            "stateVariable": false,
+                            "storageLocation": "default",
+                            "typeDescriptions": {
+                              "typeIdentifier": "t_uint256",
+                              "typeString": "uint256"
+                            },
+                            "typeName": {
+                              "id": 1221,
+                              "name": "uint256",
+                              "nodeType": "ElementaryTypeName",
+                              "src": "31297:7:1",
+                              "typeDescriptions": {
+                                "typeIdentifier": "t_uint256",
+                                "typeString": "uint256"
+                              }
+                            },
+                            "value": null,
+                            "visibility": "internal"
+                          }
+                        ],
+                        "id": 1228,
+                        "initialValue": {
+                          "argumentTypes": null,
+                          "baseExpression": {
+                            "argumentTypes": null,
+                            "baseExpression": {
+                              "argumentTypes": null,
+                              "id": 1223,
+                              "name": "_ownedTokens",
+                              "nodeType": "Identifier",
+                              "overloadedDeclarations": [],
+                              "referencedDeclaration": 981,
+                              "src": "31319:12:1",
+                              "typeDescriptions": {
+                                "typeIdentifier": "t_mapping$_t_address_$_t_array$_t_uint256_$dyn_storage_$",
+                                "typeString": "mapping(address => uint256[] storage ref)"
+                              }
+                            },
+                            "id": 1225,
+                            "indexExpression": {
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+                              "id": 1224,
+                              "name": "from",
+                              "nodeType": "Identifier",
+                              "overloadedDeclarations": [],
+                              "referencedDeclaration": 1197,
+                              "src": "31332:4:1",
+                              "typeDescriptions": {
+                                "typeIdentifier": "t_address",
+                                "typeString": "address"
+                              }
+                            },
+                            "isConstant": false,
+                            "isLValue": true,
+                            "isPure": false,
+                            "lValueRequested": false,
+                            "nodeType": "IndexAccess",
+                            "src": "31319:18:1",
+                            "typeDescriptions": {
+                              "typeIdentifier": "t_array$_t_uint256_$dyn_storage",
+                              "typeString": "uint256[] storage ref"
+                            }
+                          },
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+                            "argumentTypes": null,
+                            "id": 1226,
+                            "name": "lastTokenIndex",
+                            "nodeType": "Identifier",
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+                            "referencedDeclaration": 1203,
+                            "src": "31338:14:1",
+                            "typeDescriptions": {
+                              "typeIdentifier": "t_uint256",
+                              "typeString": "uint256"
+                            }
+                          },
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+                          "isPure": false,
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+                          "nodeType": "IndexAccess",
+                          "src": "31319:34:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_uint256",
+                            "typeString": "uint256"
+                          }
+                        },
+                        "nodeType": "VariableDeclarationStatement",
+                        "src": "31297:56:1"
+                      },
+                      {
+                        "expression": {
+                          "argumentTypes": null,
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+                          "isConstant": false,
+                          "isLValue": false,
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+                          "lValueRequested": false,
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+                            "baseExpression": {
+                              "argumentTypes": null,
+                              "baseExpression": {
+                                "argumentTypes": null,
+                                "id": 1229,
+                                "name": "_ownedTokens",
+                                "nodeType": "Identifier",
+                                "overloadedDeclarations": [],
+                                "referencedDeclaration": 981,
+                                "src": "31368:12:1",
+                                "typeDescriptions": {
+                                  "typeIdentifier": "t_mapping$_t_address_$_t_array$_t_uint256_$dyn_storage_$",
+                                  "typeString": "mapping(address => uint256[] storage ref)"
+                                }
+                              },
+                              "id": 1232,
+                              "indexExpression": {
+                                "argumentTypes": null,
+                                "id": 1230,
+                                "name": "from",
+                                "nodeType": "Identifier",
+                                "overloadedDeclarations": [],
+                                "referencedDeclaration": 1197,
+                                "src": "31381:4:1",
+                                "typeDescriptions": {
+                                  "typeIdentifier": "t_address",
+                                  "typeString": "address"
+                                }
+                              },
+                              "isConstant": false,
+                              "isLValue": true,
+                              "isPure": false,
+                              "lValueRequested": false,
+                              "nodeType": "IndexAccess",
+                              "src": "31368:18:1",
+                              "typeDescriptions": {
+                                "typeIdentifier": "t_array$_t_uint256_$dyn_storage",
+                                "typeString": "uint256[] storage ref"
+                              }
+                            },
+                            "id": 1233,
+                            "indexExpression": {
+                              "argumentTypes": null,
+                              "id": 1231,
+                              "name": "tokenIndex",
+                              "nodeType": "Identifier",
+                              "overloadedDeclarations": [],
+                              "referencedDeclaration": 1213,
+                              "src": "31387:10:1",
+                              "typeDescriptions": {
+                                "typeIdentifier": "t_uint256",
+                                "typeString": "uint256"
+                              }
+                            },
+                            "isConstant": false,
+                            "isLValue": true,
+                            "isPure": false,
+                            "lValueRequested": true,
+                            "nodeType": "IndexAccess",
+                            "src": "31368:30:1",
+                            "typeDescriptions": {
+                              "typeIdentifier": "t_uint256",
+                              "typeString": "uint256"
+                            }
+                          },
+                          "nodeType": "Assignment",
+                          "operator": "=",
+                          "rightHandSide": {
+                            "argumentTypes": null,
+                            "id": 1234,
+                            "name": "lastTokenId",
+                            "nodeType": "Identifier",
+                            "overloadedDeclarations": [],
+                            "referencedDeclaration": 1222,
+                            "src": "31401:11:1",
+                            "typeDescriptions": {
+                              "typeIdentifier": "t_uint256",
+                              "typeString": "uint256"
+                            }
+                          },
+                          "src": "31368:44:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_uint256",
+                            "typeString": "uint256"
+                          }
+                        },
+                        "id": 1236,
+                        "nodeType": "ExpressionStatement",
+                        "src": "31368:44:1"
+                      },
+                      {
+                        "expression": {
+                          "argumentTypes": null,
+                          "id": 1241,
+                          "isConstant": false,
+                          "isLValue": false,
+                          "isPure": false,
+                          "lValueRequested": false,
+                          "leftHandSide": {
+                            "argumentTypes": null,
+                            "baseExpression": {
+                              "argumentTypes": null,
+                              "id": 1237,
+                              "name": "_ownedTokensIndex",
+                              "nodeType": "Identifier",
+                              "overloadedDeclarations": [],
+                              "referencedDeclaration": 985,
+                              "src": "31484:17:1",
+                              "typeDescriptions": {
+                                "typeIdentifier": "t_mapping$_t_uint256_$_t_uint256_$",
+                                "typeString": "mapping(uint256 => uint256)"
+                              }
+                            },
+                            "id": 1239,
+                            "indexExpression": {
+                              "argumentTypes": null,
+                              "id": 1238,
+                              "name": "lastTokenId",
+                              "nodeType": "Identifier",
+                              "overloadedDeclarations": [],
+                              "referencedDeclaration": 1222,
+                              "src": "31502:11:1",
+                              "typeDescriptions": {
+                                "typeIdentifier": "t_uint256",
+                                "typeString": "uint256"
+                              }
+                            },
+                            "isConstant": false,
+                            "isLValue": true,
+                            "isPure": false,
+                            "lValueRequested": true,
+                            "nodeType": "IndexAccess",
+                            "src": "31484:30:1",
+                            "typeDescriptions": {
+                              "typeIdentifier": "t_uint256",
+                              "typeString": "uint256"
+                            }
+                          },
+                          "nodeType": "Assignment",
+                          "operator": "=",
+                          "rightHandSide": {
+                            "argumentTypes": null,
+                            "id": 1240,
+                            "name": "tokenIndex",
+                            "nodeType": "Identifier",
+                            "overloadedDeclarations": [],
+                            "referencedDeclaration": 1213,
+                            "src": "31517:10:1",
+                            "typeDescriptions": {
+                              "typeIdentifier": "t_uint256",
+                              "typeString": "uint256"
+                            }
+                          },
+                          "src": "31484:43:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_uint256",
+                            "typeString": "uint256"
+                          }
+                        },
+                        "id": 1242,
+                        "nodeType": "ExpressionStatement",
+                        "src": "31484:43:1"
+                      }
+                    ]
+                  }
+                },
+                {
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+                    "id": 1249,
+                    "isConstant": false,
+                    "isLValue": false,
+                    "isPure": false,
+                    "lValueRequested": false,
+                    "nodeType": "UnaryOperation",
+                    "operator": "--",
+                    "prefix": false,
+                    "src": "31658:27:1",
+                    "subExpression": {
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+                      "expression": {
+                        "argumentTypes": null,
+                        "baseExpression": {
+                          "argumentTypes": null,
+                          "id": 1245,
+                          "name": "_ownedTokens",
+                          "nodeType": "Identifier",
+                          "overloadedDeclarations": [],
+                          "referencedDeclaration": 981,
+                          "src": "31658:12:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_mapping$_t_address_$_t_array$_t_uint256_$dyn_storage_$",
+                            "typeString": "mapping(address => uint256[] storage ref)"
+                          }
+                        },
+                        "id": 1247,
+                        "indexExpression": {
+                          "argumentTypes": null,
+                          "id": 1246,
+                          "name": "from",
+                          "nodeType": "Identifier",
+                          "overloadedDeclarations": [],
+                          "referencedDeclaration": 1197,
+                          "src": "31671:4:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_address",
+                            "typeString": "address"
+                          }
+                        },
+                        "isConstant": false,
+                        "isLValue": true,
+                        "isPure": false,
+                        "lValueRequested": false,
+                        "nodeType": "IndexAccess",
+                        "src": "31658:18:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_array$_t_uint256_$dyn_storage",
+                          "typeString": "uint256[] storage ref"
+                        }
+                      },
+                      "id": 1248,
+                      "isConstant": false,
+                      "isLValue": true,
+                      "isPure": false,
+                      "lValueRequested": true,
+                      "memberName": "length",
+                      "nodeType": "MemberAccess",
+                      "referencedDeclaration": null,
+                      "src": "31658:25:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_uint256",
+                        "typeString": "uint256"
+                      }
+                    },
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_uint256",
+                      "typeString": "uint256"
+                    }
+                  },
+                  "id": 1250,
+                  "nodeType": "ExpressionStatement",
+                  "src": "31658:27:1"
+                }
+              ]
+            },
+            "documentation": "@dev Private function to remove a token from this extension's ownership-tracking data structures. Note that\nwhile the token is not assigned a new owner, the _ownedTokensIndex mapping is _not_ updated: this allows for\ngas optimizations e.g. when performing a transfer operation (avoiding double writes).\nThis has O(1) time complexity, but alters the order of the _ownedTokens array.\n@param from address representing the previous owner of the given token ID\n@param tokenId uint256 ID of the token to be removed from the tokens list of the given address",
+            "id": 1252,
+            "implemented": true,
+            "kind": "function",
+            "modifiers": [],
+            "name": "_removeTokenFromOwnerEnumeration",
+            "nodeType": "FunctionDefinition",
+            "parameters": {
+              "id": 1200,
+              "nodeType": "ParameterList",
+              "parameters": [
+                {
+                  "constant": false,
+                  "id": 1197,
+                  "name": "from",
+                  "nodeType": "VariableDeclaration",
+                  "scope": 1252,
+                  "src": "30815:12:1",
+                  "stateVariable": false,
+                  "storageLocation": "default",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_address",
+                    "typeString": "address"
+                  },
+                  "typeName": {
+                    "id": 1196,
+                    "name": "address",
+                    "nodeType": "ElementaryTypeName",
+                    "src": "30815:7:1",
+                    "stateMutability": "nonpayable",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_address",
+                      "typeString": "address"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                },
+                {
+                  "constant": false,
+                  "id": 1199,
+                  "name": "tokenId",
+                  "nodeType": "VariableDeclaration",
+                  "scope": 1252,
+                  "src": "30829:15:1",
+                  "stateVariable": false,
+                  "storageLocation": "default",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_uint256",
+                    "typeString": "uint256"
+                  },
+                  "typeName": {
+                    "id": 1198,
+                    "name": "uint256",
+                    "nodeType": "ElementaryTypeName",
+                    "src": "30829:7:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_uint256",
+                      "typeString": "uint256"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                }
+              ],
+              "src": "30814:31:1"
+            },
+            "returnParameters": {
+              "id": 1201,
+              "nodeType": "ParameterList",
+              "parameters": [],
+              "src": "30854:0:1"
+            },
+            "scope": 1302,
+            "src": "30773:1128:1",
+            "stateMutability": "nonpayable",
+            "superFunction": null,
+            "visibility": "private"
+          },
+          {
+            "body": {
+              "id": 1300,
+              "nodeType": "Block",
+              "src": "32260:993:1",
+              "statements": [
+                {
+                  "assignments": [
+                    1258
+                  ],
+                  "declarations": [
+                    {
+                      "constant": false,
+                      "id": 1258,
+                      "name": "lastTokenIndex",
+                      "nodeType": "VariableDeclaration",
+                      "scope": 1300,
+                      "src": "32438:22:1",
+                      "stateVariable": false,
+                      "storageLocation": "default",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_uint256",
+                        "typeString": "uint256"
+                      },
+                      "typeName": {
+                        "id": 1257,
+                        "name": "uint256",
+                        "nodeType": "ElementaryTypeName",
+                        "src": "32438:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      },
+                      "value": null,
+                      "visibility": "internal"
+                    }
+                  ],
+                  "id": 1264,
+                  "initialValue": {
+                    "argumentTypes": null,
+                    "arguments": [
+                      {
+                        "argumentTypes": null,
+                        "hexValue": "31",
+                        "id": 1262,
+                        "isConstant": false,
+                        "isLValue": false,
+                        "isPure": true,
+                        "kind": "number",
+                        "lValueRequested": false,
+                        "nodeType": "Literal",
+                        "src": "32485:1:1",
+                        "subdenomination": null,
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_rational_1_by_1",
+                          "typeString": "int_const 1"
+                        },
+                        "value": "1"
+                      }
+                    ],
+                    "expression": {
+                      "argumentTypes": [
+                        {
+                          "typeIdentifier": "t_rational_1_by_1",
+                          "typeString": "int_const 1"
+                        }
+                      ],
+                      "expression": {
+                        "argumentTypes": null,
+                        "expression": {
+                          "argumentTypes": null,
+                          "id": 1259,
+                          "name": "_allTokens",
+                          "nodeType": "Identifier",
+                          "overloadedDeclarations": [],
+                          "referencedDeclaration": 988,
+                          "src": "32463:10:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_array$_t_uint256_$dyn_storage",
+                            "typeString": "uint256[] storage ref"
+                          }
+                        },
+                        "id": 1260,
+                        "isConstant": false,
+                        "isLValue": true,
+                        "isPure": false,
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+                        "src": "36290:5:1",
+                        "typeDescriptions": {
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+                          "typeString": "address"
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+                        "name": "tokenId",
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+                        "src": "36297:7:1",
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+                        "src": "36278:5:1",
+                        "typeDescriptions": {
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+                          "typeString": "contract super ERC721Metadata"
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+                      "src": "36278:11:1",
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+                              "src": "36361:10:1",
+                              "typeDescriptions": {
+                                "typeIdentifier": "t_mapping$_t_uint256_$_t_string_storage_$",
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+                              "src": "36372:7:1",
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+                        "kind": "typeConversion",
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+                          "isLValue": false,
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+                          "nodeType": "UnaryOperation",
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+                          "src": "36409:26:1",
+                          "subExpression": {
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+                            "baseExpression": {
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+                              "nodeType": "Identifier",
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+                              "referencedDeclaration": 1338,
+                              "src": "36416:10:1",
+                              "typeDescriptions": {
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+                              "src": "36427:7:1",
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+                            "isLValue": true,
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+                            "typeString": "tuple()"
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+                    "name": "address",
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+                  "visibility": "internal"
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+                  "storageLocation": "default",
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+                      "typeString": "uint256"
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+            "src": "36212:240:1",
+            "stateMutability": "nonpayable",
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+        "src": "33817:2637:1"
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+        "literals": [
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+          "^",
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+          ".0"
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+        "nodeType": "PragmaDirective",
+        "src": "36518:23:1"
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+            "baseName": {
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+              "id": 1450,
+              "name": "ERC721",
+              "nodeType": "UserDefinedTypeName",
+              "referencedDeclaration": 944,
+              "src": "36838:6:1",
+              "typeDescriptions": {
+                "typeIdentifier": "t_contract$_ERC721_$944",
+                "typeString": "contract ERC721"
+              }
+            },
+            "id": 1451,
+            "nodeType": "InheritanceSpecifier",
+            "src": "36838:6:1"
+          },
+          {
+            "arguments": null,
+            "baseName": {
+              "contractScope": null,
+              "id": 1452,
+              "name": "ERC721Enumerable",
+              "nodeType": "UserDefinedTypeName",
+              "referencedDeclaration": 1302,
+              "src": "36846:16:1",
+              "typeDescriptions": {
+                "typeIdentifier": "t_contract$_ERC721Enumerable_$1302",
+                "typeString": "contract ERC721Enumerable"
+              }
+            },
+            "id": 1453,
+            "nodeType": "InheritanceSpecifier",
+            "src": "36846:16:1"
+          },
+          {
+            "arguments": null,
+            "baseName": {
+              "contractScope": null,
+              "id": 1454,
+              "name": "ERC721Metadata",
+              "nodeType": "UserDefinedTypeName",
+              "referencedDeclaration": 1448,
+              "src": "36864:14:1",
+              "typeDescriptions": {
+                "typeIdentifier": "t_contract$_ERC721Metadata_$1448",
+                "typeString": "contract ERC721Metadata"
+              }
+            },
+            "id": 1455,
+            "nodeType": "InheritanceSpecifier",
+            "src": "36864:14:1"
+          }
+        ],
+        "contractDependencies": [
+          944,
+          969,
+          23,
+          124,
+          386,
+          1302,
+          1323,
+          1448
+        ],
+        "contractKind": "contract",
+        "documentation": "@title Full ERC721 Token\nThis implementation includes all the required and some optional functionality of the ERC721 standard\nMoreover, it includes approve all functionality using operator terminology\n@dev see https://eips.ethereum.org/EIPS/eip-721",
+        "fullyImplemented": true,
+        "id": 1468,
+        "linearizedBaseContracts": [
+          1468,
+          1448,
+          1323,
+          1302,
+          969,
+          944,
+          124,
+          386,
+          23
+        ],
+        "name": "ERC721Full",
+        "nodeType": "ContractDefinition",
+        "nodes": [
+          {
+            "body": {
+              "id": 1466,
+              "nodeType": "Block",
+              "src": "36976:64:1",
+              "statements": []
+            },
+            "documentation": null,
+            "id": 1467,
+            "implemented": true,
+            "kind": "constructor",
+            "modifiers": [
+              {
+                "arguments": [
+                  {
+                    "argumentTypes": null,
+                    "id": 1462,
+                    "name": "name",
+                    "nodeType": "Identifier",
+                    "overloadedDeclarations": [],
+                    "referencedDeclaration": 1457,
+                    "src": "36962:4:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_string_memory_ptr",
+                      "typeString": "string memory"
+                    }
+                  },
+                  {
+                    "argumentTypes": null,
+                    "id": 1463,
+                    "name": "symbol",
+                    "nodeType": "Identifier",
+                    "overloadedDeclarations": [],
+                    "referencedDeclaration": 1459,
+                    "src": "36968:6:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_string_memory_ptr",
+                      "typeString": "string memory"
+                    }
+                  }
+                ],
+                "id": 1464,
+                "modifierName": {
+                  "argumentTypes": null,
+                  "id": 1461,
+                  "name": "ERC721Metadata",
+                  "nodeType": "Identifier",
+                  "overloadedDeclarations": [],
+                  "referencedDeclaration": 1448,
+                  "src": "36947:14:1",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_type$_t_contract$_ERC721Metadata_$1448_$",
+                    "typeString": "type(contract ERC721Metadata)"
+                  }
+                },
+                "nodeType": "ModifierInvocation",
+                "src": "36947:28:1"
+              }
+            ],
+            "name": "",
+            "nodeType": "FunctionDefinition",
+            "parameters": {
+              "id": 1460,
+              "nodeType": "ParameterList",
+              "parameters": [
+                {
+                  "constant": false,
+                  "id": 1457,
+                  "name": "name",
+                  "nodeType": "VariableDeclaration",
+                  "scope": 1467,
+                  "src": "36898:18:1",
+                  "stateVariable": false,
+                  "storageLocation": "memory",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_string_memory_ptr",
+                    "typeString": "string"
+                  },
+                  "typeName": {
+                    "id": 1456,
+                    "name": "string",
+                    "nodeType": "ElementaryTypeName",
+                    "src": "36898:6:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_string_storage_ptr",
+                      "typeString": "string"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                },
+                {
+                  "constant": false,
+                  "id": 1459,
+                  "name": "symbol",
+                  "nodeType": "VariableDeclaration",
+                  "scope": 1467,
+                  "src": "36918:20:1",
+                  "stateVariable": false,
+                  "storageLocation": "memory",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_string_memory_ptr",
+                    "typeString": "string"
+                  },
+                  "typeName": {
+                    "id": 1458,
+                    "name": "string",
+                    "nodeType": "ElementaryTypeName",
+                    "src": "36918:6:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_string_storage_ptr",
+                      "typeString": "string"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                }
+              ],
+              "src": "36897:42:1"
+            },
+            "returnParameters": {
+              "id": 1465,
+              "nodeType": "ParameterList",
+              "parameters": [],
+              "src": "36976:0:1"
+            },
+            "scope": 1468,
+            "src": "36885:155:1",
+            "stateMutability": "nonpayable",
+            "superFunction": null,
+            "visibility": "public"
+          }
+        ],
+        "scope": 1469,
+        "src": "36815:227:1"
+      }
+    ],
+    "src": "61:36982:1"
+  },
+  "compiler": {
+    "name": "solc",
+    "version": "0.5.0+commit.1d4f565a.Emscripten.clang"
+  },
+  "networks": {},
+  "schemaVersion": "3.0.2",
+  "updatedAt": "2019-09-05T15:01:08.957Z",
+  "devdoc": {
+    "details": "See https://eips.ethereum.org/EIPS/eip-721",
+    "methods": {
+      "balanceOf(address)": {
+        "details": "Returns the number of NFTs in `owner`'s account."
+      },
+      "ownerOf(uint256)": {
+        "details": "Returns the owner of the NFT specified by `tokenId`."
+      },
+      "safeTransferFrom(address,address,uint256)": {
+        "details": "Transfers a specific NFT (`tokenId`) from one account (`from`) to another (`to`).     *      * Requirements: - `from`, `to` cannot be zero. - `tokenId` must be owned by `from`. - If the caller is not `from`, it must be have been allowed to move this NFT by either `approve` or `setApproveForAll`."
+      },
+      "supportsInterface(bytes4)": {
+        "details": "Returns true if this contract implements the interface defined by `interfaceId`. See the corresponding [EIP section](https://eips.ethereum.org/EIPS/eip-165#how-interfaces-are-identified) to learn more about how these ids are created.     * This function call must use less than 30 000 gas."
+      },
+      "transferFrom(address,address,uint256)": {
+        "details": "Transfers a specific NFT (`tokenId`) from one account (`from`) to another (`to`).     * Requirements: - If the caller is not `from`, it must be approved to move this NFT by either `approve` or `setApproveForAll`."
+      }
+    },
+    "title": "ERC-721 Non-Fungible Token Standard, optional metadata extension"
+  },
+  "userdoc": {
+    "methods": {}
+  }
+}
\ No newline at end of file
diff --git a/src/abis/IERC721Receiver.json b/src/abis/IERC721Receiver.json
new file mode 100644
index 0000000..ba8d307
--- /dev/null
+++ b/src/abis/IERC721Receiver.json
@@ -0,0 +1,37496 @@
+{
+  "contractName": "IERC721Receiver",
+  "abi": [
+    {
+      "constant": false,
+      "inputs": [
+        {
+          "name": "operator",
+          "type": "address"
+        },
+        {
+          "name": "from",
+          "type": "address"
+        },
+        {
+          "name": "tokenId",
+          "type": "uint256"
+        },
+        {
+          "name": "data",
+          "type": "bytes"
+        }
+      ],
+      "name": "onERC721Received",
+      "outputs": [
+        {
+          "name": "",
+          "type": "bytes4"
+        }
+      ],
+      "payable": false,
+      "stateMutability": "nonpayable",
+      "type": "function"
+    }
+  ],
+  "bytecode": "0x",
+  "deployedBytecode": "0x",
+  "sourceMap": "",
+  "deployedSourceMap": "",
+  "source": "\n// File: @openzeppelin/contracts/introspection/IERC165.sol\n\npragma solidity ^0.5.0;\n\n/**\n * @dev Interface of the ERC165 standard, as defined in the\n * [EIP](https://eips.ethereum.org/EIPS/eip-165).\n *\n * Implementers can declare support of contract interfaces, which can then be\n * queried by others (`ERC165Checker`).\n *\n * For an implementation, see `ERC165`.\n */\ninterface IERC165 {\n    /**\n     * @dev Returns true if this contract implements the interface defined by\n     * `interfaceId`. See the corresponding\n     * [EIP section](https://eips.ethereum.org/EIPS/eip-165#how-interfaces-are-identified)\n     * to learn more about how these ids are created.\n     *\n     * This function call must use less than 30 000 gas.\n     */\n    function supportsInterface(bytes4 interfaceId) external view returns (bool);\n}\n\n// File: @openzeppelin/contracts/token/ERC721/IERC721.sol\n\npragma solidity ^0.5.0;\n\n\n/**\n * @dev Required interface of an ERC721 compliant contract.\n */\ncontract IERC721 is IERC165 {\n    event Transfer(address indexed from, address indexed to, uint256 indexed tokenId);\n    event Approval(address indexed owner, address indexed approved, uint256 indexed tokenId);\n    event ApprovalForAll(address indexed owner, address indexed operator, bool approved);\n\n    /**\n     * @dev Returns the number of NFTs in `owner`'s account.\n     */\n    function balanceOf(address owner) public view returns (uint256 balance);\n\n    /**\n     * @dev Returns the owner of the NFT specified by `tokenId`.\n     */\n    function ownerOf(uint256 tokenId) public view returns (address owner);\n\n    /**\n     * @dev Transfers a specific NFT (`tokenId`) from one account (`from`) to\n     * another (`to`).\n     *\n     * \n     *\n     * Requirements:\n     * - `from`, `to` cannot be zero.\n     * - `tokenId` must be owned by `from`.\n     * - If the caller is not `from`, it must be have been allowed to move this\n     * NFT by either `approve` or `setApproveForAll`.\n     */\n    function safeTransferFrom(address from, address to, uint256 tokenId) public;\n    /**\n     * @dev Transfers a specific NFT (`tokenId`) from one account (`from`) to\n     * another (`to`).\n     *\n     * Requirements:\n     * - If the caller is not `from`, it must be approved to move this NFT by\n     * either `approve` or `setApproveForAll`.\n     */\n    function transferFrom(address from, address to, uint256 tokenId) public;\n    function approve(address to, uint256 tokenId) public;\n    function getApproved(uint256 tokenId) public view returns (address operator);\n\n    function setApprovalForAll(address operator, bool _approved) public;\n    function isApprovedForAll(address owner, address operator) public view returns (bool);\n\n\n    function safeTransferFrom(address from, address to, uint256 tokenId, bytes memory data) public;\n}\n\n// File: @openzeppelin/contracts/token/ERC721/IERC721Receiver.sol\n\npragma solidity ^0.5.0;\n\n/**\n * @title ERC721 token receiver interface\n * @dev Interface for any contract that wants to support safeTransfers\n * from ERC721 asset contracts.\n */\ncontract IERC721Receiver {\n    /**\n     * @notice Handle the receipt of an NFT\n     * @dev The ERC721 smart contract calls this function on the recipient\n     * after a `safeTransfer`. This function MUST return the function selector,\n     * otherwise the caller will revert the transaction. The selector to be\n     * returned can be obtained as `this.onERC721Received.selector`. This\n     * function MAY throw to revert and reject the transfer.\n     * Note: the ERC721 contract address is always the message sender.\n     * @param operator The address which called `safeTransferFrom` function\n     * @param from The address which previously owned the token\n     * @param tokenId The NFT identifier which is being transferred\n     * @param data Additional data with no specified format\n     * @return bytes4 `bytes4(keccak256(\"onERC721Received(address,address,uint256,bytes)\"))`\n     */\n    function onERC721Received(address operator, address from, uint256 tokenId, bytes memory data)\n    public returns (bytes4);\n}\n\n// File: @openzeppelin/contracts/math/SafeMath.sol\n\npragma solidity ^0.5.0;\n\n/**\n * @dev Wrappers over Solidity's arithmetic operations with added overflow\n * checks.\n *\n * Arithmetic operations in Solidity wrap on overflow. This can easily result\n * in bugs, because programmers usually assume that an overflow raises an\n * error, which is the standard behavior in high level programming languages.\n * `SafeMath` restores this intuition by reverting the transaction when an\n * operation overflows.\n *\n * Using this library instead of the unchecked operations eliminates an entire\n * class of bugs, so it's recommended to use it always.\n */\nlibrary SafeMath {\n    /**\n     * @dev Returns the addition of two unsigned integers, reverting on\n     * overflow.\n     *\n     * Counterpart to Solidity's `+` operator.\n     *\n     * Requirements:\n     * - Addition cannot overflow.\n     */\n    function add(uint256 a, uint256 b) internal pure returns (uint256) {\n        uint256 c = a + b;\n        require(c >= a, \"SafeMath: addition overflow\");\n\n        return c;\n    }\n\n    /**\n     * @dev Returns the subtraction of two unsigned integers, reverting on\n     * overflow (when the result is negative).\n     *\n     * Counterpart to Solidity's `-` operator.\n     *\n     * Requirements:\n     * - Subtraction cannot overflow.\n     */\n    function sub(uint256 a, uint256 b) internal pure returns (uint256) {\n        require(b <= a, \"SafeMath: subtraction overflow\");\n        uint256 c = a - b;\n\n        return c;\n    }\n\n    /**\n     * @dev Returns the multiplication of two unsigned integers, reverting on\n     * overflow.\n     *\n     * Counterpart to Solidity's `*` operator.\n     *\n     * Requirements:\n     * - Multiplication cannot overflow.\n     */\n    function mul(uint256 a, uint256 b) internal pure returns (uint256) {\n        // Gas optimization: this is cheaper than requiring 'a' not being zero, but the\n        // benefit is lost if 'b' is also tested.\n        // See: https://github.com/OpenZeppelin/openzeppelin-contracts/pull/522\n        if (a == 0) {\n            return 0;\n        }\n\n        uint256 c = a * b;\n        require(c / a == b, \"SafeMath: multiplication overflow\");\n\n        return c;\n    }\n\n    /**\n     * @dev Returns the integer division of two unsigned integers. Reverts on\n     * division by zero. The result is rounded towards zero.\n     *\n     * Counterpart to Solidity's `/` operator. Note: this function uses a\n     * `revert` opcode (which leaves remaining gas untouched) while Solidity\n     * uses an invalid opcode to revert (consuming all remaining gas).\n     *\n     * Requirements:\n     * - The divisor cannot be zero.\n     */\n    function div(uint256 a, uint256 b) internal pure returns (uint256) {\n        // Solidity only automatically asserts when dividing by 0\n        require(b > 0, \"SafeMath: division by zero\");\n        uint256 c = a / b;\n        // assert(a == b * c + a % b); // There is no case in which this doesn't hold\n\n        return c;\n    }\n\n    /**\n     * @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo),\n     * Reverts when dividing by zero.\n     *\n     * Counterpart to Solidity's `%` operator. This function uses a `revert`\n     * opcode (which leaves remaining gas untouched) while Solidity uses an\n     * invalid opcode to revert (consuming all remaining gas).\n     *\n     * Requirements:\n     * - The divisor cannot be zero.\n     */\n    function mod(uint256 a, uint256 b) internal pure returns (uint256) {\n        require(b != 0, \"SafeMath: modulo by zero\");\n        return a % b;\n    }\n}\n\n// File: @openzeppelin/contracts/utils/Address.sol\n\npragma solidity ^0.5.0;\n\n/**\n * @dev Collection of functions related to the address type,\n */\nlibrary Address {\n    /**\n     * @dev Returns true if `account` is a contract.\n     *\n     * This test is non-exhaustive, and there may be false-negatives: during the\n     * execution of a contract's constructor, its address will be reported as\n     * not containing a contract.\n     *\n     * > It is unsafe to assume that an address for which this function returns\n     * false is an externally-owned account (EOA) and not a contract.\n     */\n    function isContract(address account) internal view returns (bool) {\n        // This method relies in extcodesize, which returns 0 for contracts in\n        // construction, since the code is only stored at the end of the\n        // constructor execution.\n\n        uint256 size;\n        // solhint-disable-next-line no-inline-assembly\n        assembly { size := extcodesize(account) }\n        return size > 0;\n    }\n}\n\n// File: @openzeppelin/contracts/drafts/Counters.sol\n\npragma solidity ^0.5.0;\n\n\n/**\n * @title Counters\n * @author Matt Condon (@shrugs)\n * @dev Provides counters that can only be incremented or decremented by one. This can be used e.g. to track the number\n * of elements in a mapping, issuing ERC721 ids, or counting request ids.\n *\n * Include with `using Counters for Counters.Counter;`\n * Since it is not possible to overflow a 256 bit integer with increments of one, `increment` can skip the SafeMath\n * overflow check, thereby saving gas. This does assume however correct usage, in that the underlying `_value` is never\n * directly accessed.\n */\nlibrary Counters {\n    using SafeMath for uint256;\n\n    struct Counter {\n        // This variable should never be directly accessed by users of the library: interactions must be restricted to\n        // the library's function. As of Solidity v0.5.2, this cannot be enforced, though there is a proposal to add\n        // this feature: see https://github.com/ethereum/solidity/issues/4637\n        uint256 _value; // default: 0\n    }\n\n    function current(Counter storage counter) internal view returns (uint256) {\n        return counter._value;\n    }\n\n    function increment(Counter storage counter) internal {\n        counter._value += 1;\n    }\n\n    function decrement(Counter storage counter) internal {\n        counter._value = counter._value.sub(1);\n    }\n}\n\n// File: @openzeppelin/contracts/introspection/ERC165.sol\n\npragma solidity ^0.5.0;\n\n\n/**\n * @dev Implementation of the `IERC165` interface.\n *\n * Contracts may inherit from this and call `_registerInterface` to declare\n * their support of an interface.\n */\ncontract ERC165 is IERC165 {\n    /*\n     * bytes4(keccak256('supportsInterface(bytes4)')) == 0x01ffc9a7\n     */\n    bytes4 private constant _INTERFACE_ID_ERC165 = 0x01ffc9a7;\n\n    /**\n     * @dev Mapping of interface ids to whether or not it's supported.\n     */\n    mapping(bytes4 => bool) private _supportedInterfaces;\n\n    constructor () internal {\n        // Derived contracts need only register support for their own interfaces,\n        // we register support for ERC165 itself here\n        _registerInterface(_INTERFACE_ID_ERC165);\n    }\n\n    /**\n     * @dev See `IERC165.supportsInterface`.\n     *\n     * Time complexity O(1), guaranteed to always use less than 30 000 gas.\n     */\n    function supportsInterface(bytes4 interfaceId) external view returns (bool) {\n        return _supportedInterfaces[interfaceId];\n    }\n\n    /**\n     * @dev Registers the contract as an implementer of the interface defined by\n     * `interfaceId`. Support of the actual ERC165 interface is automatic and\n     * registering its interface id is not required.\n     *\n     * See `IERC165.supportsInterface`.\n     *\n     * Requirements:\n     *\n     * - `interfaceId` cannot be the ERC165 invalid interface (`0xffffffff`).\n     */\n    function _registerInterface(bytes4 interfaceId) internal {\n        require(interfaceId != 0xffffffff, \"ERC165: invalid interface id\");\n        _supportedInterfaces[interfaceId] = true;\n    }\n}\n\n// File: @openzeppelin/contracts/token/ERC721/ERC721.sol\n\npragma solidity ^0.5.0;\n\n\n\n\n\n\n\n/**\n * @title ERC721 Non-Fungible Token Standard basic implementation\n * @dev see https://eips.ethereum.org/EIPS/eip-721\n */\ncontract ERC721 is ERC165, IERC721 {\n    using SafeMath for uint256;\n    using Address for address;\n    using Counters for Counters.Counter;\n\n    // Equals to `bytes4(keccak256(\"onERC721Received(address,address,uint256,bytes)\"))`\n    // which can be also obtained as `IERC721Receiver(0).onERC721Received.selector`\n    bytes4 private constant _ERC721_RECEIVED = 0x150b7a02;\n\n    // Mapping from token ID to owner\n    mapping (uint256 => address) private _tokenOwner;\n\n    // Mapping from token ID to approved address\n    mapping (uint256 => address) private _tokenApprovals;\n\n    // Mapping from owner to number of owned token\n    mapping (address => Counters.Counter) private _ownedTokensCount;\n\n    // Mapping from owner to operator approvals\n    mapping (address => mapping (address => bool)) private _operatorApprovals;\n\n    /*\n     *     bytes4(keccak256('balanceOf(address)')) == 0x70a08231\n     *     bytes4(keccak256('ownerOf(uint256)')) == 0x6352211e\n     *     bytes4(keccak256('approve(address,uint256)')) == 0x095ea7b3\n     *     bytes4(keccak256('getApproved(uint256)')) == 0x081812fc\n     *     bytes4(keccak256('setApprovalForAll(address,bool)')) == 0xa22cb465\n     *     bytes4(keccak256('isApprovedForAll(address,address)')) == 0xe985e9c\n     *     bytes4(keccak256('transferFrom(address,address,uint256)')) == 0x23b872dd\n     *     bytes4(keccak256('safeTransferFrom(address,address,uint256)')) == 0x42842e0e\n     *     bytes4(keccak256('safeTransferFrom(address,address,uint256,bytes)')) == 0xb88d4fde\n     *\n     *     => 0x70a08231 ^ 0x6352211e ^ 0x095ea7b3 ^ 0x081812fc ^\n     *        0xa22cb465 ^ 0xe985e9c ^ 0x23b872dd ^ 0x42842e0e ^ 0xb88d4fde == 0x80ac58cd\n     */\n    bytes4 private constant _INTERFACE_ID_ERC721 = 0x80ac58cd;\n\n    constructor () public {\n        // register the supported interfaces to conform to ERC721 via ERC165\n        _registerInterface(_INTERFACE_ID_ERC721);\n    }\n\n    /**\n     * @dev Gets the balance of the specified address.\n     * @param owner address to query the balance of\n     * @return uint256 representing the amount owned by the passed address\n     */\n    function balanceOf(address owner) public view returns (uint256) {\n        require(owner != address(0), \"ERC721: balance query for the zero address\");\n\n        return _ownedTokensCount[owner].current();\n    }\n\n    /**\n     * @dev Gets the owner of the specified token ID.\n     * @param tokenId uint256 ID of the token to query the owner of\n     * @return address currently marked as the owner of the given token ID\n     */\n    function ownerOf(uint256 tokenId) public view returns (address) {\n        address owner = _tokenOwner[tokenId];\n        require(owner != address(0), \"ERC721: owner query for nonexistent token\");\n\n        return owner;\n    }\n\n    /**\n     * @dev Approves another address to transfer the given token ID\n     * The zero address indicates there is no approved address.\n     * There can only be one approved address per token at a given time.\n     * Can only be called by the token owner or an approved operator.\n     * @param to address to be approved for the given token ID\n     * @param tokenId uint256 ID of the token to be approved\n     */\n    function approve(address to, uint256 tokenId) public {\n        address owner = ownerOf(tokenId);\n        require(to != owner, \"ERC721: approval to current owner\");\n\n        require(msg.sender == owner || isApprovedForAll(owner, msg.sender),\n            \"ERC721: approve caller is not owner nor approved for all\"\n        );\n\n        _tokenApprovals[tokenId] = to;\n        emit Approval(owner, to, tokenId);\n    }\n\n    /**\n     * @dev Gets the approved address for a token ID, or zero if no address set\n     * Reverts if the token ID does not exist.\n     * @param tokenId uint256 ID of the token to query the approval of\n     * @return address currently approved for the given token ID\n     */\n    function getApproved(uint256 tokenId) public view returns (address) {\n        require(_exists(tokenId), \"ERC721: approved query for nonexistent token\");\n\n        return _tokenApprovals[tokenId];\n    }\n\n    /**\n     * @dev Sets or unsets the approval of a given operator\n     * An operator is allowed to transfer all tokens of the sender on their behalf.\n     * @param to operator address to set the approval\n     * @param approved representing the status of the approval to be set\n     */\n    function setApprovalForAll(address to, bool approved) public {\n        require(to != msg.sender, \"ERC721: approve to caller\");\n\n        _operatorApprovals[msg.sender][to] = approved;\n        emit ApprovalForAll(msg.sender, to, approved);\n    }\n\n    /**\n     * @dev Tells whether an operator is approved by a given owner.\n     * @param owner owner address which you want to query the approval of\n     * @param operator operator address which you want to query the approval of\n     * @return bool whether the given operator is approved by the given owner\n     */\n    function isApprovedForAll(address owner, address operator) public view returns (bool) {\n        return _operatorApprovals[owner][operator];\n    }\n\n    /**\n     * @dev Transfers the ownership of a given token ID to another address.\n     * Usage of this method is discouraged, use `safeTransferFrom` whenever possible.\n     * Requires the msg.sender to be the owner, approved, or operator.\n     * @param from current owner of the token\n     * @param to address to receive the ownership of the given token ID\n     * @param tokenId uint256 ID of the token to be transferred\n     */\n    function transferFrom(address from, address to, uint256 tokenId) public {\n        //solhint-disable-next-line max-line-length\n        require(_isApprovedOrOwner(msg.sender, tokenId), \"ERC721: transfer caller is not owner nor approved\");\n\n        _transferFrom(from, to, tokenId);\n    }\n\n    /**\n     * @dev Safely transfers the ownership of a given token ID to another address\n     * If the target address is a contract, it must implement `onERC721Received`,\n     * which is called upon a safe transfer, and return the magic value\n     * `bytes4(keccak256(\"onERC721Received(address,address,uint256,bytes)\"))`; otherwise,\n     * the transfer is reverted.\n     * Requires the msg.sender to be the owner, approved, or operator\n     * @param from current owner of the token\n     * @param to address to receive the ownership of the given token ID\n     * @param tokenId uint256 ID of the token to be transferred\n     */\n    function safeTransferFrom(address from, address to, uint256 tokenId) public {\n        safeTransferFrom(from, to, tokenId, \"\");\n    }\n\n    /**\n     * @dev Safely transfers the ownership of a given token ID to another address\n     * If the target address is a contract, it must implement `onERC721Received`,\n     * which is called upon a safe transfer, and return the magic value\n     * `bytes4(keccak256(\"onERC721Received(address,address,uint256,bytes)\"))`; otherwise,\n     * the transfer is reverted.\n     * Requires the msg.sender to be the owner, approved, or operator\n     * @param from current owner of the token\n     * @param to address to receive the ownership of the given token ID\n     * @param tokenId uint256 ID of the token to be transferred\n     * @param _data bytes data to send along with a safe transfer check\n     */\n    function safeTransferFrom(address from, address to, uint256 tokenId, bytes memory _data) public {\n        transferFrom(from, to, tokenId);\n        require(_checkOnERC721Received(from, to, tokenId, _data), \"ERC721: transfer to non ERC721Receiver implementer\");\n    }\n\n    /**\n     * @dev Returns whether the specified token exists.\n     * @param tokenId uint256 ID of the token to query the existence of\n     * @return bool whether the token exists\n     */\n    function _exists(uint256 tokenId) internal view returns (bool) {\n        address owner = _tokenOwner[tokenId];\n        return owner != address(0);\n    }\n\n    /**\n     * @dev Returns whether the given spender can transfer a given token ID.\n     * @param spender address of the spender to query\n     * @param tokenId uint256 ID of the token to be transferred\n     * @return bool whether the msg.sender is approved for the given token ID,\n     * is an operator of the owner, or is the owner of the token\n     */\n    function _isApprovedOrOwner(address spender, uint256 tokenId) internal view returns (bool) {\n        require(_exists(tokenId), \"ERC721: operator query for nonexistent token\");\n        address owner = ownerOf(tokenId);\n        return (spender == owner || getApproved(tokenId) == spender || isApprovedForAll(owner, spender));\n    }\n\n    /**\n     * @dev Internal function to mint a new token.\n     * Reverts if the given token ID already exists.\n     * @param to The address that will own the minted token\n     * @param tokenId uint256 ID of the token to be minted\n     */\n    function _mint(address to, uint256 tokenId) internal {\n        require(to != address(0), \"ERC721: mint to the zero address\");\n        require(!_exists(tokenId), \"ERC721: token already minted\");\n\n        _tokenOwner[tokenId] = to;\n        _ownedTokensCount[to].increment();\n\n        emit Transfer(address(0), to, tokenId);\n    }\n\n    /**\n     * @dev Internal function to burn a specific token.\n     * Reverts if the token does not exist.\n     * Deprecated, use _burn(uint256) instead.\n     * @param owner owner of the token to burn\n     * @param tokenId uint256 ID of the token being burned\n     */\n    function _burn(address owner, uint256 tokenId) internal {\n        require(ownerOf(tokenId) == owner, \"ERC721: burn of token that is not own\");\n\n        _clearApproval(tokenId);\n\n        _ownedTokensCount[owner].decrement();\n        _tokenOwner[tokenId] = address(0);\n\n        emit Transfer(owner, address(0), tokenId);\n    }\n\n    /**\n     * @dev Internal function to burn a specific token.\n     * Reverts if the token does not exist.\n     * @param tokenId uint256 ID of the token being burned\n     */\n    function _burn(uint256 tokenId) internal {\n        _burn(ownerOf(tokenId), tokenId);\n    }\n\n    /**\n     * @dev Internal function to transfer ownership of a given token ID to another address.\n     * As opposed to transferFrom, this imposes no restrictions on msg.sender.\n     * @param from current owner of the token\n     * @param to address to receive the ownership of the given token ID\n     * @param tokenId uint256 ID of the token to be transferred\n     */\n    function _transferFrom(address from, address to, uint256 tokenId) internal {\n        require(ownerOf(tokenId) == from, \"ERC721: transfer of token that is not own\");\n        require(to != address(0), \"ERC721: transfer to the zero address\");\n\n        _clearApproval(tokenId);\n\n        _ownedTokensCount[from].decrement();\n        _ownedTokensCount[to].increment();\n\n        _tokenOwner[tokenId] = to;\n\n        emit Transfer(from, to, tokenId);\n    }\n\n    /**\n     * @dev Internal function to invoke `onERC721Received` on a target address.\n     * The call is not executed if the target address is not a contract.\n     *\n     * This function is deprecated.\n     * @param from address representing the previous owner of the given token ID\n     * @param to target address that will receive the tokens\n     * @param tokenId uint256 ID of the token to be transferred\n     * @param _data bytes optional data to send along with the call\n     * @return bool whether the call correctly returned the expected magic value\n     */\n    function _checkOnERC721Received(address from, address to, uint256 tokenId, bytes memory _data)\n        internal returns (bool)\n    {\n        if (!to.isContract()) {\n            return true;\n        }\n\n        bytes4 retval = IERC721Receiver(to).onERC721Received(msg.sender, from, tokenId, _data);\n        return (retval == _ERC721_RECEIVED);\n    }\n\n    /**\n     * @dev Private function to clear current approval of a given token ID.\n     * @param tokenId uint256 ID of the token to be transferred\n     */\n    function _clearApproval(uint256 tokenId) private {\n        if (_tokenApprovals[tokenId] != address(0)) {\n            _tokenApprovals[tokenId] = address(0);\n        }\n    }\n}\n\n// File: @openzeppelin/contracts/token/ERC721/IERC721Enumerable.sol\n\npragma solidity ^0.5.0;\n\n\n/**\n * @title ERC-721 Non-Fungible Token Standard, optional enumeration extension\n * @dev See https://eips.ethereum.org/EIPS/eip-721\n */\ncontract IERC721Enumerable is IERC721 {\n    function totalSupply() public view returns (uint256);\n    function tokenOfOwnerByIndex(address owner, uint256 index) public view returns (uint256 tokenId);\n\n    function tokenByIndex(uint256 index) public view returns (uint256);\n}\n\n// File: @openzeppelin/contracts/token/ERC721/ERC721Enumerable.sol\n\npragma solidity ^0.5.0;\n\n\n\n\n/**\n * @title ERC-721 Non-Fungible Token with optional enumeration extension logic\n * @dev See https://eips.ethereum.org/EIPS/eip-721\n */\ncontract ERC721Enumerable is ERC165, ERC721, IERC721Enumerable {\n    // Mapping from owner to list of owned token IDs\n    mapping(address => uint256[]) private _ownedTokens;\n\n    // Mapping from token ID to index of the owner tokens list\n    mapping(uint256 => uint256) private _ownedTokensIndex;\n\n    // Array with all token ids, used for enumeration\n    uint256[] private _allTokens;\n\n    // Mapping from token id to position in the allTokens array\n    mapping(uint256 => uint256) private _allTokensIndex;\n\n    /*\n     *     bytes4(keccak256('totalSupply()')) == 0x18160ddd\n     *     bytes4(keccak256('tokenOfOwnerByIndex(address,uint256)')) == 0x2f745c59\n     *     bytes4(keccak256('tokenByIndex(uint256)')) == 0x4f6ccce7\n     *\n     *     => 0x18160ddd ^ 0x2f745c59 ^ 0x4f6ccce7 == 0x780e9d63\n     */\n    bytes4 private constant _INTERFACE_ID_ERC721_ENUMERABLE = 0x780e9d63;\n\n    /**\n     * @dev Constructor function.\n     */\n    constructor () public {\n        // register the supported interface to conform to ERC721Enumerable via ERC165\n        _registerInterface(_INTERFACE_ID_ERC721_ENUMERABLE);\n    }\n\n    /**\n     * @dev Gets the token ID at a given index of the tokens list of the requested owner.\n     * @param owner address owning the tokens list to be accessed\n     * @param index uint256 representing the index to be accessed of the requested tokens list\n     * @return uint256 token ID at the given index of the tokens list owned by the requested address\n     */\n    function tokenOfOwnerByIndex(address owner, uint256 index) public view returns (uint256) {\n        require(index < balanceOf(owner), \"ERC721Enumerable: owner index out of bounds\");\n        return _ownedTokens[owner][index];\n    }\n\n    /**\n     * @dev Gets the total amount of tokens stored by the contract.\n     * @return uint256 representing the total amount of tokens\n     */\n    function totalSupply() public view returns (uint256) {\n        return _allTokens.length;\n    }\n\n    /**\n     * @dev Gets the token ID at a given index of all the tokens in this contract\n     * Reverts if the index is greater or equal to the total number of tokens.\n     * @param index uint256 representing the index to be accessed of the tokens list\n     * @return uint256 token ID at the given index of the tokens list\n     */\n    function tokenByIndex(uint256 index) public view returns (uint256) {\n        require(index < totalSupply(), \"ERC721Enumerable: global index out of bounds\");\n        return _allTokens[index];\n    }\n\n    /**\n     * @dev Internal function to transfer ownership of a given token ID to another address.\n     * As opposed to transferFrom, this imposes no restrictions on msg.sender.\n     * @param from current owner of the token\n     * @param to address to receive the ownership of the given token ID\n     * @param tokenId uint256 ID of the token to be transferred\n     */\n    function _transferFrom(address from, address to, uint256 tokenId) internal {\n        super._transferFrom(from, to, tokenId);\n\n        _removeTokenFromOwnerEnumeration(from, tokenId);\n\n        _addTokenToOwnerEnumeration(to, tokenId);\n    }\n\n    /**\n     * @dev Internal function to mint a new token.\n     * Reverts if the given token ID already exists.\n     * @param to address the beneficiary that will own the minted token\n     * @param tokenId uint256 ID of the token to be minted\n     */\n    function _mint(address to, uint256 tokenId) internal {\n        super._mint(to, tokenId);\n\n        _addTokenToOwnerEnumeration(to, tokenId);\n\n        _addTokenToAllTokensEnumeration(tokenId);\n    }\n\n    /**\n     * @dev Internal function to burn a specific token.\n     * Reverts if the token does not exist.\n     * Deprecated, use _burn(uint256) instead.\n     * @param owner owner of the token to burn\n     * @param tokenId uint256 ID of the token being burned\n     */\n    function _burn(address owner, uint256 tokenId) internal {\n        super._burn(owner, tokenId);\n\n        _removeTokenFromOwnerEnumeration(owner, tokenId);\n        // Since tokenId will be deleted, we can clear its slot in _ownedTokensIndex to trigger a gas refund\n        _ownedTokensIndex[tokenId] = 0;\n\n        _removeTokenFromAllTokensEnumeration(tokenId);\n    }\n\n    /**\n     * @dev Gets the list of token IDs of the requested owner.\n     * @param owner address owning the tokens\n     * @return uint256[] List of token IDs owned by the requested address\n     */\n    function _tokensOfOwner(address owner) internal view returns (uint256[] storage) {\n        return _ownedTokens[owner];\n    }\n\n    /**\n     * @dev Private function to add a token to this extension's ownership-tracking data structures.\n     * @param to address representing the new owner of the given token ID\n     * @param tokenId uint256 ID of the token to be added to the tokens list of the given address\n     */\n    function _addTokenToOwnerEnumeration(address to, uint256 tokenId) private {\n        _ownedTokensIndex[tokenId] = _ownedTokens[to].length;\n        _ownedTokens[to].push(tokenId);\n    }\n\n    /**\n     * @dev Private function to add a token to this extension's token tracking data structures.\n     * @param tokenId uint256 ID of the token to be added to the tokens list\n     */\n    function _addTokenToAllTokensEnumeration(uint256 tokenId) private {\n        _allTokensIndex[tokenId] = _allTokens.length;\n        _allTokens.push(tokenId);\n    }\n\n    /**\n     * @dev Private function to remove a token from this extension's ownership-tracking data structures. Note that\n     * while the token is not assigned a new owner, the _ownedTokensIndex mapping is _not_ updated: this allows for\n     * gas optimizations e.g. when performing a transfer operation (avoiding double writes).\n     * This has O(1) time complexity, but alters the order of the _ownedTokens array.\n     * @param from address representing the previous owner of the given token ID\n     * @param tokenId uint256 ID of the token to be removed from the tokens list of the given address\n     */\n    function _removeTokenFromOwnerEnumeration(address from, uint256 tokenId) private {\n        // To prevent a gap in from's tokens array, we store the last token in the index of the token to delete, and\n        // then delete the last slot (swap and pop).\n\n        uint256 lastTokenIndex = _ownedTokens[from].length.sub(1);\n        uint256 tokenIndex = _ownedTokensIndex[tokenId];\n\n        // When the token to delete is the last token, the swap operation is unnecessary\n        if (tokenIndex != lastTokenIndex) {\n            uint256 lastTokenId = _ownedTokens[from][lastTokenIndex];\n\n            _ownedTokens[from][tokenIndex] = lastTokenId; // Move the last token to the slot of the to-delete token\n            _ownedTokensIndex[lastTokenId] = tokenIndex; // Update the moved token's index\n        }\n\n        // This also deletes the contents at the last position of the array\n        _ownedTokens[from].length--;\n\n        // Note that _ownedTokensIndex[tokenId] hasn't been cleared: it still points to the old slot (now occupied by\n        // lastTokenId, or just over the end of the array if the token was the last one).\n    }\n\n    /**\n     * @dev Private function to remove a token from this extension's token tracking data structures.\n     * This has O(1) time complexity, but alters the order of the _allTokens array.\n     * @param tokenId uint256 ID of the token to be removed from the tokens list\n     */\n    function _removeTokenFromAllTokensEnumeration(uint256 tokenId) private {\n        // To prevent a gap in the tokens array, we store the last token in the index of the token to delete, and\n        // then delete the last slot (swap and pop).\n\n        uint256 lastTokenIndex = _allTokens.length.sub(1);\n        uint256 tokenIndex = _allTokensIndex[tokenId];\n\n        // When the token to delete is the last token, the swap operation is unnecessary. However, since this occurs so\n        // rarely (when the last minted token is burnt) that we still do the swap here to avoid the gas cost of adding\n        // an 'if' statement (like in _removeTokenFromOwnerEnumeration)\n        uint256 lastTokenId = _allTokens[lastTokenIndex];\n\n        _allTokens[tokenIndex] = lastTokenId; // Move the last token to the slot of the to-delete token\n        _allTokensIndex[lastTokenId] = tokenIndex; // Update the moved token's index\n\n        // This also deletes the contents at the last position of the array\n        _allTokens.length--;\n        _allTokensIndex[tokenId] = 0;\n    }\n}\n\n// File: @openzeppelin/contracts/token/ERC721/IERC721Metadata.sol\n\npragma solidity ^0.5.0;\n\n\n/**\n * @title ERC-721 Non-Fungible Token Standard, optional metadata extension\n * @dev See https://eips.ethereum.org/EIPS/eip-721\n */\ncontract IERC721Metadata is IERC721 {\n    function name() external view returns (string memory);\n    function symbol() external view returns (string memory);\n    function tokenURI(uint256 tokenId) external view returns (string memory);\n}\n\n// File: @openzeppelin/contracts/token/ERC721/ERC721Metadata.sol\n\npragma solidity ^0.5.0;\n\n\n\n\ncontract ERC721Metadata is ERC165, ERC721, IERC721Metadata {\n    // Token name\n    string private _name;\n\n    // Token symbol\n    string private _symbol;\n\n    // Optional mapping for token URIs\n    mapping(uint256 => string) private _tokenURIs;\n\n    /*\n     *     bytes4(keccak256('name()')) == 0x06fdde03\n     *     bytes4(keccak256('symbol()')) == 0x95d89b41\n     *     bytes4(keccak256('tokenURI(uint256)')) == 0xc87b56dd\n     *\n     *     => 0x06fdde03 ^ 0x95d89b41 ^ 0xc87b56dd == 0x5b5e139f\n     */\n    bytes4 private constant _INTERFACE_ID_ERC721_METADATA = 0x5b5e139f;\n\n    /**\n     * @dev Constructor function\n     */\n    constructor (string memory name, string memory symbol) public {\n        _name = name;\n        _symbol = symbol;\n\n        // register the supported interfaces to conform to ERC721 via ERC165\n        _registerInterface(_INTERFACE_ID_ERC721_METADATA);\n    }\n\n    /**\n     * @dev Gets the token name.\n     * @return string representing the token name\n     */\n    function name() external view returns (string memory) {\n        return _name;\n    }\n\n    /**\n     * @dev Gets the token symbol.\n     * @return string representing the token symbol\n     */\n    function symbol() external view returns (string memory) {\n        return _symbol;\n    }\n\n    /**\n     * @dev Returns an URI for a given token ID.\n     * Throws if the token ID does not exist. May return an empty string.\n     * @param tokenId uint256 ID of the token to query\n     */\n    function tokenURI(uint256 tokenId) external view returns (string memory) {\n        require(_exists(tokenId), \"ERC721Metadata: URI query for nonexistent token\");\n        return _tokenURIs[tokenId];\n    }\n\n    /**\n     * @dev Internal function to set the token URI for a given token.\n     * Reverts if the token ID does not exist.\n     * @param tokenId uint256 ID of the token to set its URI\n     * @param uri string URI to assign\n     */\n    function _setTokenURI(uint256 tokenId, string memory uri) internal {\n        require(_exists(tokenId), \"ERC721Metadata: URI set of nonexistent token\");\n        _tokenURIs[tokenId] = uri;\n    }\n\n    /**\n     * @dev Internal function to burn a specific token.\n     * Reverts if the token does not exist.\n     * Deprecated, use _burn(uint256) instead.\n     * @param owner owner of the token to burn\n     * @param tokenId uint256 ID of the token being burned by the msg.sender\n     */\n    function _burn(address owner, uint256 tokenId) internal {\n        super._burn(owner, tokenId);\n\n        // Clear metadata (if any)\n        if (bytes(_tokenURIs[tokenId]).length != 0) {\n            delete _tokenURIs[tokenId];\n        }\n    }\n}\n\n// File: @openzeppelin/contracts/token/ERC721/ERC721Full.sol\n\npragma solidity ^0.5.0;\n\n\n\n\n/**\n * @title Full ERC721 Token\n * This implementation includes all the required and some optional functionality of the ERC721 standard\n * Moreover, it includes approve all functionality using operator terminology\n * @dev see https://eips.ethereum.org/EIPS/eip-721\n */\ncontract ERC721Full is ERC721, ERC721Enumerable, ERC721Metadata {\n    constructor (string memory name, string memory symbol) public ERC721Metadata(name, symbol) {\n        // solhint-disable-previous-line no-empty-blocks\n    }\n}\n",
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+                          "src": "21564:17:1",
+                          "typeDescriptions": {
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+                          "id": 789,
+                          "name": "owner",
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+                          "src": "21582:5:1",
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+                            "typeString": "address"
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+                          "typeString": "address payable"
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+                          "typeString": "uint256"
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+                          "typeString": "address"
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+                          "typeString": "address payable"
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+                          "typeString": "uint256"
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+                      "typeString": "address"
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+                              "typeString": "uint256"
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+                          ],
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+                          "typeDescriptions": {
+                            "typeIdentifier": "t_magic_message",
+                            "typeString": "msg"
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+                          "typeString": "address payable"
+                        }
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+                        "src": "23642:4:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
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+                        "name": "tokenId",
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+                        "src": "23648:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
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+                        "src": "23657:5:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_bytes_memory_ptr",
+                          "typeString": "bytes memory"
+                        }
+                      }
+                    ],
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+                      "argumentTypes": [
+                        {
+                          "typeIdentifier": "t_address_payable",
+                          "typeString": "address payable"
+                        },
+                        {
+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        },
+                        {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        },
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+                          "typeIdentifier": "t_bytes_memory_ptr",
+                          "typeString": "bytes memory"
+                        }
+                      ],
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+                        "arguments": [
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+                            "argumentTypes": null,
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+                            }
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+                          "name": "IERC721Receiver",
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+                          "src": "23593:15:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_type$_t_contract$_IERC721Receiver_$139_$",
+                            "typeString": "type(contract IERC721Receiver)"
+                          }
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+                          "typeIdentifier": "t_contract$_IERC721Receiver_$139",
+                          "typeString": "contract IERC721Receiver"
+                        }
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+                      }
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+                    "nodeType": "FunctionCall",
+                    "src": "23593:70:1",
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+                      "typeIdentifier": "t_bytes4",
+                      "typeString": "bytes4"
+                    }
+                  },
+                  "nodeType": "VariableDeclarationStatement",
+                  "src": "23577:86:1"
+                },
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+                    "components": [
+                      {
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+                        "commonType": {
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+                          "typeString": "bytes4"
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+                        "isPure": false,
+                        "lValueRequested": false,
+                        "leftExpression": {
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+                          "name": "retval",
+                          "nodeType": "Identifier",
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+                            "typeIdentifier": "t_bytes4",
+                            "typeString": "bytes4"
+                          }
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+                        "operator": "==",
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+                          "name": "_ERC721_RECEIVED",
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+                          "referencedDeclaration": 403,
+                          "src": "23691:16:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_bytes4",
+                            "typeString": "bytes4"
+                          }
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+                }
+              ]
+            },
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+                      "typeString": "uint256"
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+                  "visibility": "internal"
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+                      "typeString": "bytes"
+                    }
+                  },
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+                }
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+              "src": "23399:63:1"
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+                  "storageLocation": "default",
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+                    "typeString": "bool"
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+                    "src": "23489:4:1",
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+                      "typeString": "bool"
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+                  "visibility": "internal"
+                }
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+                        "src": "23940:15:1",
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+                          "typeIdentifier": "t_mapping$_t_uint256_$_t_address_$",
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+                        "src": "23956:7:1",
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+                          "subdenomination": null,
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_rational_0_by_1",
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+                          },
+                          "value": "0"
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+                            "typeIdentifier": "t_rational_0_by_1",
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+                        "isPure": true,
+                        "lValueRequested": false,
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+                        "typeDescriptions": {
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+                          "typeString": "type(address)"
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+                      "typeDescriptions": {
+                        "typeIdentifier": "t_address_payable",
+                        "typeString": "address payable"
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+                          "leftHandSide": {
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+                              "name": "_tokenApprovals",
+                              "nodeType": "Identifier",
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+                              "referencedDeclaration": 411,
+                              "src": "23994:15:1",
+                              "typeDescriptions": {
+                                "typeIdentifier": "t_mapping$_t_uint256_$_t_address_$",
+                                "typeString": "mapping(uint256 => address)"
+                              }
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+                              "name": "tokenId",
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+                                "typeIdentifier": "t_type$_t_address_$",
+                                "typeString": "type(address)"
+                              },
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+                            "kind": "typeConversion",
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+                            "names": [],
+                            "nodeType": "FunctionCall",
+                            "src": "24021:10:1",
+                            "typeDescriptions": {
+                              "typeIdentifier": "t_address_payable",
+                              "typeString": "address payable"
+                            }
+                          },
+                          "src": "23994:37:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_address",
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+                        "nodeType": "ExpressionStatement",
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+                      }
+                    ]
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+            },
+            "documentation": "@dev Private function to clear current approval of a given token ID.\n@param tokenId uint256 ID of the token to be transferred",
+            "id": 943,
+            "implemented": true,
+            "kind": "function",
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+                  "stateVariable": false,
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+                    "name": "uint256",
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+                    "src": "23901:7:1",
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+                    }
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+                  "visibility": "internal"
+                }
+              ],
+              "src": "23900:17:1"
+            },
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+              "src": "23926:0:1"
+            },
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+            "src": "23877:171:1",
+            "stateMutability": "nonpayable",
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+            "visibility": "private"
+          }
+        ],
+        "scope": 1469,
+        "src": "11949:12101:1"
+      },
+      {
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+        "literals": [
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+          ".0"
+        ],
+        "nodeType": "PragmaDirective",
+        "src": "24121:23:1"
+      },
+      {
+        "baseContracts": [
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+            "baseName": {
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+              "id": 946,
+              "name": "IERC721",
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+              "src": "24314:7:1",
+              "typeDescriptions": {
+                "typeIdentifier": "t_contract$_IERC721_$124",
+                "typeString": "contract IERC721"
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+            "nodeType": "InheritanceSpecifier",
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+        "documentation": "@title ERC-721 Non-Fungible Token Standard, optional enumeration extension\n@dev See https://eips.ethereum.org/EIPS/eip-721",
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+        "id": 969,
+        "linearizedBaseContracts": [
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+        "name": "IERC721Enumerable",
+        "nodeType": "ContractDefinition",
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+                        "src": "26476:12:1",
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+                          "typeString": "mapping(address => uint256[] storage ref)"
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+                        "name": "owner",
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+                          "typeString": "address"
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+                          "name": "index",
+                          "nodeType": "Identifier",
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+                          "src": "27179:5:1",
+                          "typeDescriptions": {
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+                          "arguments": [],
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+                            "id": 1046,
+                            "name": "totalSupply",
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+                            ],
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+                            "src": "27187:11:1",
+                            "typeDescriptions": {
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+                              "typeString": "function () view returns (uint256)"
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+                          "nodeType": "FunctionCall",
+                          "src": "27187:13:1",
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+                            "typeIdentifier": "t_uint256",
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+                        "nodeType": "Literal",
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+                          "typeString": "literal_string \"ERC721Enumerable: global index out of bounds\""
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+                      "name": "_allTokens",
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+                      "src": "27266:10:1",
+                      "typeDescriptions": {
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+                      "name": "index",
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+                      "src": "27277:5:1",
+                      "typeDescriptions": {
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+                        "typeString": "uint256"
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+            "documentation": "@dev Gets the token ID at a given index of all the tokens in this contract\nReverts if the index is greater or equal to the total number of tokens.\n@param index uint256 representing the index to be accessed of the tokens list\n@return uint256 token ID at the given index of the tokens list",
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+            "implemented": true,
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+                    "name": "uint256",
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+                      "typeString": "uint256"
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+                  "storageLocation": "default",
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+                        "src": "27770:4:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        }
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+                        "id": 1070,
+                        "name": "to",
+                        "nodeType": "Identifier",
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+                        "typeDescriptions": {
+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
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+                        "id": 1071,
+                        "name": "tokenId",
+                        "nodeType": "Identifier",
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+                        "src": "27780:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
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+                          "typeString": "address"
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+                        "src": "27832:4:1",
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+                          "typeString": "address"
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+                        "id": 1076,
+                        "name": "tokenId",
+                        "nodeType": "Identifier",
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+                        "src": "27885:2:1",
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+                          "typeString": "address"
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+                        "name": "tokenId",
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+                          "typeString": "uint256"
+                        }
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+                        {
+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        },
+                        {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
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+                      "name": "_addTokenToOwnerEnumeration",
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+                      "src": "27857:27:1",
+                      "typeDescriptions": {
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+                }
+              ]
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+            "kind": "function",
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+            "name": "_transferFrom",
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+                  "storageLocation": "default",
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+                    "typeIdentifier": "t_address",
+                    "typeString": "address"
+                  },
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+                    "name": "address",
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+                    "src": "27688:7:1",
+                    "stateMutability": "nonpayable",
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+                      "typeIdentifier": "t_address",
+                      "typeString": "address"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                },
+                {
+                  "constant": false,
+                  "id": 1061,
+                  "name": "to",
+                  "nodeType": "VariableDeclaration",
+                  "scope": 1085,
+                  "src": "27702:10:1",
+                  "stateVariable": false,
+                  "storageLocation": "default",
+                  "typeDescriptions": {
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+                    "typeString": "address"
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+                    "id": 1060,
+                    "name": "address",
+                    "nodeType": "ElementaryTypeName",
+                    "src": "27702:7:1",
+                    "stateMutability": "nonpayable",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_address",
+                      "typeString": "address"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                },
+                {
+                  "constant": false,
+                  "id": 1063,
+                  "name": "tokenId",
+                  "nodeType": "VariableDeclaration",
+                  "scope": 1085,
+                  "src": "27714:15:1",
+                  "stateVariable": false,
+                  "storageLocation": "default",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_uint256",
+                    "typeString": "uint256"
+                  },
+                  "typeName": {
+                    "id": 1062,
+                    "name": "uint256",
+                    "nodeType": "ElementaryTypeName",
+                    "src": "27714:7:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_uint256",
+                      "typeString": "uint256"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                }
+              ],
+              "src": "27687:43:1"
+            },
+            "returnParameters": {
+              "id": 1065,
+              "nodeType": "ParameterList",
+              "parameters": [],
+              "src": "27740:0:1"
+            },
+            "scope": 1302,
+            "src": "27665:239:1",
+            "stateMutability": "nonpayable",
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+            "visibility": "internal"
+          },
+          {
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+              "nodeType": "Block",
+              "src": "28214:143:1",
+              "statements": [
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+                    "arguments": [
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+                        "id": 1095,
+                        "name": "to",
+                        "nodeType": "Identifier",
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+                        "referencedDeclaration": 1087,
+                        "src": "28236:2:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        }
+                      },
+                      {
+                        "argumentTypes": null,
+                        "id": 1096,
+                        "name": "tokenId",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 1089,
+                        "src": "28240:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      }
+                    ],
+                    "expression": {
+                      "argumentTypes": [
+                        {
+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        },
+                        {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      ],
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+                        "id": 1092,
+                        "name": "super",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 1572,
+                        "src": "28224:5:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_super$_ERC721Enumerable_$1302",
+                          "typeString": "contract super ERC721Enumerable"
+                        }
+                      },
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+                      "isConstant": false,
+                      "isLValue": false,
+                      "isPure": false,
+                      "lValueRequested": false,
+                      "memberName": "_mint",
+                      "nodeType": "MemberAccess",
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+                      "src": "28224:11:1",
+                      "typeDescriptions": {
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+                        "typeString": "function (address,uint256)"
+                      }
+                    },
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+                    "isLValue": false,
+                    "isPure": false,
+                    "kind": "functionCall",
+                    "lValueRequested": false,
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+                    "src": "28224:24:1",
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+                      "typeString": "tuple()"
+                    }
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+                  "src": "28224:24:1"
+                },
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+                        "id": 1100,
+                        "name": "to",
+                        "nodeType": "Identifier",
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+                        "referencedDeclaration": 1087,
+                        "src": "28287:2:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        }
+                      },
+                      {
+                        "argumentTypes": null,
+                        "id": 1101,
+                        "name": "tokenId",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 1089,
+                        "src": "28291:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      }
+                    ],
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+                      "argumentTypes": [
+                        {
+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        },
+                        {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      ],
+                      "id": 1099,
+                      "name": "_addTokenToOwnerEnumeration",
+                      "nodeType": "Identifier",
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+                      "referencedDeclaration": 1176,
+                      "src": "28259:27:1",
+                      "typeDescriptions": {
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+                        "typeString": "function (address,uint256)"
+                      }
+                    },
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+                    "isConstant": false,
+                    "isLValue": false,
+                    "isPure": false,
+                    "kind": "functionCall",
+                    "lValueRequested": false,
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+                    "nodeType": "FunctionCall",
+                    "src": "28259:40:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_tuple$__$",
+                      "typeString": "tuple()"
+                    }
+                  },
+                  "id": 1103,
+                  "nodeType": "ExpressionStatement",
+                  "src": "28259:40:1"
+                },
+                {
+                  "expression": {
+                    "argumentTypes": null,
+                    "arguments": [
+                      {
+                        "argumentTypes": null,
+                        "id": 1105,
+                        "name": "tokenId",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 1089,
+                        "src": "28342:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      }
+                    ],
+                    "expression": {
+                      "argumentTypes": [
+                        {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      ],
+                      "id": 1104,
+                      "name": "_addTokenToAllTokensEnumeration",
+                      "nodeType": "Identifier",
+                      "overloadedDeclarations": [],
+                      "referencedDeclaration": 1195,
+                      "src": "28310:31:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_function_internal_nonpayable$_t_uint256_$returns$__$",
+                        "typeString": "function (uint256)"
+                      }
+                    },
+                    "id": 1106,
+                    "isConstant": false,
+                    "isLValue": false,
+                    "isPure": false,
+                    "kind": "functionCall",
+                    "lValueRequested": false,
+                    "names": [],
+                    "nodeType": "FunctionCall",
+                    "src": "28310:40:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_tuple$__$",
+                      "typeString": "tuple()"
+                    }
+                  },
+                  "id": 1107,
+                  "nodeType": "ExpressionStatement",
+                  "src": "28310:40:1"
+                }
+              ]
+            },
+            "documentation": "@dev Internal function to mint a new token.\nReverts if the given token ID already exists.\n@param to address the beneficiary that will own the minted token\n@param tokenId uint256 ID of the token to be minted",
+            "id": 1109,
+            "implemented": true,
+            "kind": "function",
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+            "name": "_mint",
+            "nodeType": "FunctionDefinition",
+            "parameters": {
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+              "nodeType": "ParameterList",
+              "parameters": [
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+                  "constant": false,
+                  "id": 1087,
+                  "name": "to",
+                  "nodeType": "VariableDeclaration",
+                  "scope": 1109,
+                  "src": "28176:10:1",
+                  "stateVariable": false,
+                  "storageLocation": "default",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_address",
+                    "typeString": "address"
+                  },
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+                    "id": 1086,
+                    "name": "address",
+                    "nodeType": "ElementaryTypeName",
+                    "src": "28176:7:1",
+                    "stateMutability": "nonpayable",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_address",
+                      "typeString": "address"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                },
+                {
+                  "constant": false,
+                  "id": 1089,
+                  "name": "tokenId",
+                  "nodeType": "VariableDeclaration",
+                  "scope": 1109,
+                  "src": "28188:15:1",
+                  "stateVariable": false,
+                  "storageLocation": "default",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_uint256",
+                    "typeString": "uint256"
+                  },
+                  "typeName": {
+                    "id": 1088,
+                    "name": "uint256",
+                    "nodeType": "ElementaryTypeName",
+                    "src": "28188:7:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_uint256",
+                      "typeString": "uint256"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                }
+              ],
+              "src": "28175:29:1"
+            },
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+              "id": 1091,
+              "nodeType": "ParameterList",
+              "parameters": [],
+              "src": "28214:0:1"
+            },
+            "scope": 1302,
+            "src": "28161:196:1",
+            "stateMutability": "nonpayable",
+            "superFunction": 768,
+            "visibility": "internal"
+          },
+          {
+            "body": {
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+              "nodeType": "Block",
+              "src": "28688:308:1",
+              "statements": [
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+                    "arguments": [
+                      {
+                        "argumentTypes": null,
+                        "id": 1119,
+                        "name": "owner",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 1111,
+                        "src": "28710:5:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        }
+                      },
+                      {
+                        "argumentTypes": null,
+                        "id": 1120,
+                        "name": "tokenId",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 1113,
+                        "src": "28717:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      }
+                    ],
+                    "expression": {
+                      "argumentTypes": [
+                        {
+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        },
+                        {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      ],
+                      "expression": {
+                        "argumentTypes": null,
+                        "id": 1116,
+                        "name": "super",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 1572,
+                        "src": "28698:5:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_super$_ERC721Enumerable_$1302",
+                          "typeString": "contract super ERC721Enumerable"
+                        }
+                      },
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+                      "isConstant": false,
+                      "isLValue": false,
+                      "isPure": false,
+                      "lValueRequested": false,
+                      "memberName": "_burn",
+                      "nodeType": "MemberAccess",
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+                      "src": "28698:11:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_function_internal_nonpayable$_t_address_$_t_uint256_$returns$__$",
+                        "typeString": "function (address,uint256)"
+                      }
+                    },
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+                    "isLValue": false,
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+                    "kind": "functionCall",
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+                    "src": "28698:27:1",
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+                      "typeString": "tuple()"
+                    }
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+                  "id": 1122,
+                  "nodeType": "ExpressionStatement",
+                  "src": "28698:27:1"
+                },
+                {
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+                    "arguments": [
+                      {
+                        "argumentTypes": null,
+                        "id": 1124,
+                        "name": "owner",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 1111,
+                        "src": "28769:5:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        }
+                      },
+                      {
+                        "argumentTypes": null,
+                        "id": 1125,
+                        "name": "tokenId",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 1113,
+                        "src": "28776:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      }
+                    ],
+                    "expression": {
+                      "argumentTypes": [
+                        {
+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        },
+                        {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      ],
+                      "id": 1123,
+                      "name": "_removeTokenFromOwnerEnumeration",
+                      "nodeType": "Identifier",
+                      "overloadedDeclarations": [],
+                      "referencedDeclaration": 1252,
+                      "src": "28736:32:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_function_internal_nonpayable$_t_address_$_t_uint256_$returns$__$",
+                        "typeString": "function (address,uint256)"
+                      }
+                    },
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+                    "isConstant": false,
+                    "isLValue": false,
+                    "isPure": false,
+                    "kind": "functionCall",
+                    "lValueRequested": false,
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+                    "nodeType": "FunctionCall",
+                    "src": "28736:48:1",
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+                      "typeIdentifier": "t_tuple$__$",
+                      "typeString": "tuple()"
+                    }
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+                  "id": 1127,
+                  "nodeType": "ExpressionStatement",
+                  "src": "28736:48:1"
+                },
+                {
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+                    "id": 1132,
+                    "isConstant": false,
+                    "isLValue": false,
+                    "isPure": false,
+                    "lValueRequested": false,
+                    "leftHandSide": {
+                      "argumentTypes": null,
+                      "baseExpression": {
+                        "argumentTypes": null,
+                        "id": 1128,
+                        "name": "_ownedTokensIndex",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 985,
+                        "src": "28903:17:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_mapping$_t_uint256_$_t_uint256_$",
+                          "typeString": "mapping(uint256 => uint256)"
+                        }
+                      },
+                      "id": 1130,
+                      "indexExpression": {
+                        "argumentTypes": null,
+                        "id": 1129,
+                        "name": "tokenId",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 1113,
+                        "src": "28921:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      },
+                      "isConstant": false,
+                      "isLValue": true,
+                      "isPure": false,
+                      "lValueRequested": true,
+                      "nodeType": "IndexAccess",
+                      "src": "28903:26:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_uint256",
+                        "typeString": "uint256"
+                      }
+                    },
+                    "nodeType": "Assignment",
+                    "operator": "=",
+                    "rightHandSide": {
+                      "argumentTypes": null,
+                      "hexValue": "30",
+                      "id": 1131,
+                      "isConstant": false,
+                      "isLValue": false,
+                      "isPure": true,
+                      "kind": "number",
+                      "lValueRequested": false,
+                      "nodeType": "Literal",
+                      "src": "28932:1:1",
+                      "subdenomination": null,
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_rational_0_by_1",
+                        "typeString": "int_const 0"
+                      },
+                      "value": "0"
+                    },
+                    "src": "28903:30:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_uint256",
+                      "typeString": "uint256"
+                    }
+                  },
+                  "id": 1133,
+                  "nodeType": "ExpressionStatement",
+                  "src": "28903:30:1"
+                },
+                {
+                  "expression": {
+                    "argumentTypes": null,
+                    "arguments": [
+                      {
+                        "argumentTypes": null,
+                        "id": 1135,
+                        "name": "tokenId",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 1113,
+                        "src": "28981:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      }
+                    ],
+                    "expression": {
+                      "argumentTypes": [
+                        {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      ],
+                      "id": 1134,
+                      "name": "_removeTokenFromAllTokensEnumeration",
+                      "nodeType": "Identifier",
+                      "overloadedDeclarations": [],
+                      "referencedDeclaration": 1301,
+                      "src": "28944:36:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_function_internal_nonpayable$_t_uint256_$returns$__$",
+                        "typeString": "function (uint256)"
+                      }
+                    },
+                    "id": 1136,
+                    "isConstant": false,
+                    "isLValue": false,
+                    "isPure": false,
+                    "kind": "functionCall",
+                    "lValueRequested": false,
+                    "names": [],
+                    "nodeType": "FunctionCall",
+                    "src": "28944:45:1",
+                    "typeDescriptions": {
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+                      "typeString": "tuple()"
+                    }
+                  },
+                  "id": 1137,
+                  "nodeType": "ExpressionStatement",
+                  "src": "28944:45:1"
+                }
+              ]
+            },
+            "documentation": "@dev Internal function to burn a specific token.\nReverts if the token does not exist.\nDeprecated, use _burn(uint256) instead.\n@param owner owner of the token to burn\n@param tokenId uint256 ID of the token being burned",
+            "id": 1139,
+            "implemented": true,
+            "kind": "function",
+            "modifiers": [],
+            "name": "_burn",
+            "nodeType": "FunctionDefinition",
+            "parameters": {
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+              "parameters": [
+                {
+                  "constant": false,
+                  "id": 1111,
+                  "name": "owner",
+                  "nodeType": "VariableDeclaration",
+                  "scope": 1139,
+                  "src": "28647:13:1",
+                  "stateVariable": false,
+                  "storageLocation": "default",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_address",
+                    "typeString": "address"
+                  },
+                  "typeName": {
+                    "id": 1110,
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+                        "src": "31090:1:1",
+                        "subdenomination": null,
+                        "typeDescriptions": {
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+                          "typeString": "int_const 1"
+                        },
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+                      }
+                    ],
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+                            "referencedDeclaration": 981,
+                            "src": "31060:12:1",
+                            "typeDescriptions": {
+                              "typeIdentifier": "t_mapping$_t_address_$_t_array$_t_uint256_$dyn_storage_$",
+                              "typeString": "mapping(address => uint256[] storage ref)"
+                            }
+                          },
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+                            "src": "31073:4:1",
+                            "typeDescriptions": {
+                              "typeIdentifier": "t_address",
+                              "typeString": "address"
+                            }
+                          },
+                          "isConstant": false,
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+                          "isPure": false,
+                          "lValueRequested": false,
+                          "nodeType": "IndexAccess",
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+                          "typeDescriptions": {
+                            "typeIdentifier": "t_array$_t_uint256_$dyn_storage",
+                            "typeString": "uint256[] storage ref"
+                          }
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+                        "memberName": "length",
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+                        "src": "31060:25:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
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+                      "src": "31060:29:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_function_internal_pure$_t_uint256_$_t_uint256_$returns$_t_uint256_$bound_to$_t_uint256_$",
+                        "typeString": "function (uint256,uint256) pure returns (uint256)"
+                      }
+                    },
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+                    "isConstant": false,
+                    "isLValue": false,
+                    "isPure": false,
+                    "kind": "functionCall",
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+                    "nodeType": "FunctionCall",
+                    "src": "31060:32:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_uint256",
+                      "typeString": "uint256"
+                    }
+                  },
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+                  "src": "31035:57:1"
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+                  ],
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+                      "stateVariable": false,
+                      "storageLocation": "default",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_uint256",
+                        "typeString": "uint256"
+                      },
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+                        "id": 1212,
+                        "name": "uint256",
+                        "nodeType": "ElementaryTypeName",
+                        "src": "31102:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      },
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+                    }
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+                      "typeDescriptions": {
+                        "typeIdentifier": "t_mapping$_t_uint256_$_t_uint256_$",
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+                      }
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+                      "typeDescriptions": {
+                        "typeIdentifier": "t_uint256",
+                        "typeString": "uint256"
+                      }
+                    },
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+                    "lValueRequested": false,
+                    "nodeType": "IndexAccess",
+                    "src": "31123:26:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_uint256",
+                      "typeString": "uint256"
+                    }
+                  },
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+                },
+                {
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+                      "src": "31253:10:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_uint256",
+                        "typeString": "uint256"
+                      }
+                    },
+                    "nodeType": "BinaryOperation",
+                    "operator": "!=",
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+                      "id": 1219,
+                      "name": "lastTokenIndex",
+                      "nodeType": "Identifier",
+                      "overloadedDeclarations": [],
+                      "referencedDeclaration": 1203,
+                      "src": "31267:14:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_uint256",
+                        "typeString": "uint256"
+                      }
+                    },
+                    "src": "31253:28:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_bool",
+                      "typeString": "bool"
+                    }
+                  },
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+                  "id": 1244,
+                  "nodeType": "IfStatement",
+                  "src": "31249:323:1",
+                  "trueBody": {
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+                    "nodeType": "Block",
+                    "src": "31283:289:1",
+                    "statements": [
+                      {
+                        "assignments": [
+                          1222
+                        ],
+                        "declarations": [
+                          {
+                            "constant": false,
+                            "id": 1222,
+                            "name": "lastTokenId",
+                            "nodeType": "VariableDeclaration",
+                            "scope": 1243,
+                            "src": "31297:19:1",
+                            "stateVariable": false,
+                            "storageLocation": "default",
+                            "typeDescriptions": {
+                              "typeIdentifier": "t_uint256",
+                              "typeString": "uint256"
+                            },
+                            "typeName": {
+                              "id": 1221,
+                              "name": "uint256",
+                              "nodeType": "ElementaryTypeName",
+                              "src": "31297:7:1",
+                              "typeDescriptions": {
+                                "typeIdentifier": "t_uint256",
+                                "typeString": "uint256"
+                              }
+                            },
+                            "value": null,
+                            "visibility": "internal"
+                          }
+                        ],
+                        "id": 1228,
+                        "initialValue": {
+                          "argumentTypes": null,
+                          "baseExpression": {
+                            "argumentTypes": null,
+                            "baseExpression": {
+                              "argumentTypes": null,
+                              "id": 1223,
+                              "name": "_ownedTokens",
+                              "nodeType": "Identifier",
+                              "overloadedDeclarations": [],
+                              "referencedDeclaration": 981,
+                              "src": "31319:12:1",
+                              "typeDescriptions": {
+                                "typeIdentifier": "t_mapping$_t_address_$_t_array$_t_uint256_$dyn_storage_$",
+                                "typeString": "mapping(address => uint256[] storage ref)"
+                              }
+                            },
+                            "id": 1225,
+                            "indexExpression": {
+                              "argumentTypes": null,
+                              "id": 1224,
+                              "name": "from",
+                              "nodeType": "Identifier",
+                              "overloadedDeclarations": [],
+                              "referencedDeclaration": 1197,
+                              "src": "31332:4:1",
+                              "typeDescriptions": {
+                                "typeIdentifier": "t_address",
+                                "typeString": "address"
+                              }
+                            },
+                            "isConstant": false,
+                            "isLValue": true,
+                            "isPure": false,
+                            "lValueRequested": false,
+                            "nodeType": "IndexAccess",
+                            "src": "31319:18:1",
+                            "typeDescriptions": {
+                              "typeIdentifier": "t_array$_t_uint256_$dyn_storage",
+                              "typeString": "uint256[] storage ref"
+                            }
+                          },
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+                            "argumentTypes": null,
+                            "id": 1226,
+                            "name": "lastTokenIndex",
+                            "nodeType": "Identifier",
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+                            "referencedDeclaration": 1203,
+                            "src": "31338:14:1",
+                            "typeDescriptions": {
+                              "typeIdentifier": "t_uint256",
+                              "typeString": "uint256"
+                            }
+                          },
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+                          "isPure": false,
+                          "lValueRequested": false,
+                          "nodeType": "IndexAccess",
+                          "src": "31319:34:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_uint256",
+                            "typeString": "uint256"
+                          }
+                        },
+                        "nodeType": "VariableDeclarationStatement",
+                        "src": "31297:56:1"
+                      },
+                      {
+                        "expression": {
+                          "argumentTypes": null,
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+                          "isLValue": false,
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+                          "lValueRequested": false,
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+                            "baseExpression": {
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+                              "baseExpression": {
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+                                "id": 1229,
+                                "name": "_ownedTokens",
+                                "nodeType": "Identifier",
+                                "overloadedDeclarations": [],
+                                "referencedDeclaration": 981,
+                                "src": "31368:12:1",
+                                "typeDescriptions": {
+                                  "typeIdentifier": "t_mapping$_t_address_$_t_array$_t_uint256_$dyn_storage_$",
+                                  "typeString": "mapping(address => uint256[] storage ref)"
+                                }
+                              },
+                              "id": 1232,
+                              "indexExpression": {
+                                "argumentTypes": null,
+                                "id": 1230,
+                                "name": "from",
+                                "nodeType": "Identifier",
+                                "overloadedDeclarations": [],
+                                "referencedDeclaration": 1197,
+                                "src": "31381:4:1",
+                                "typeDescriptions": {
+                                  "typeIdentifier": "t_address",
+                                  "typeString": "address"
+                                }
+                              },
+                              "isConstant": false,
+                              "isLValue": true,
+                              "isPure": false,
+                              "lValueRequested": false,
+                              "nodeType": "IndexAccess",
+                              "src": "31368:18:1",
+                              "typeDescriptions": {
+                                "typeIdentifier": "t_array$_t_uint256_$dyn_storage",
+                                "typeString": "uint256[] storage ref"
+                              }
+                            },
+                            "id": 1233,
+                            "indexExpression": {
+                              "argumentTypes": null,
+                              "id": 1231,
+                              "name": "tokenIndex",
+                              "nodeType": "Identifier",
+                              "overloadedDeclarations": [],
+                              "referencedDeclaration": 1213,
+                              "src": "31387:10:1",
+                              "typeDescriptions": {
+                                "typeIdentifier": "t_uint256",
+                                "typeString": "uint256"
+                              }
+                            },
+                            "isConstant": false,
+                            "isLValue": true,
+                            "isPure": false,
+                            "lValueRequested": true,
+                            "nodeType": "IndexAccess",
+                            "src": "31368:30:1",
+                            "typeDescriptions": {
+                              "typeIdentifier": "t_uint256",
+                              "typeString": "uint256"
+                            }
+                          },
+                          "nodeType": "Assignment",
+                          "operator": "=",
+                          "rightHandSide": {
+                            "argumentTypes": null,
+                            "id": 1234,
+                            "name": "lastTokenId",
+                            "nodeType": "Identifier",
+                            "overloadedDeclarations": [],
+                            "referencedDeclaration": 1222,
+                            "src": "31401:11:1",
+                            "typeDescriptions": {
+                              "typeIdentifier": "t_uint256",
+                              "typeString": "uint256"
+                            }
+                          },
+                          "src": "31368:44:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_uint256",
+                            "typeString": "uint256"
+                          }
+                        },
+                        "id": 1236,
+                        "nodeType": "ExpressionStatement",
+                        "src": "31368:44:1"
+                      },
+                      {
+                        "expression": {
+                          "argumentTypes": null,
+                          "id": 1241,
+                          "isConstant": false,
+                          "isLValue": false,
+                          "isPure": false,
+                          "lValueRequested": false,
+                          "leftHandSide": {
+                            "argumentTypes": null,
+                            "baseExpression": {
+                              "argumentTypes": null,
+                              "id": 1237,
+                              "name": "_ownedTokensIndex",
+                              "nodeType": "Identifier",
+                              "overloadedDeclarations": [],
+                              "referencedDeclaration": 985,
+                              "src": "31484:17:1",
+                              "typeDescriptions": {
+                                "typeIdentifier": "t_mapping$_t_uint256_$_t_uint256_$",
+                                "typeString": "mapping(uint256 => uint256)"
+                              }
+                            },
+                            "id": 1239,
+                            "indexExpression": {
+                              "argumentTypes": null,
+                              "id": 1238,
+                              "name": "lastTokenId",
+                              "nodeType": "Identifier",
+                              "overloadedDeclarations": [],
+                              "referencedDeclaration": 1222,
+                              "src": "31502:11:1",
+                              "typeDescriptions": {
+                                "typeIdentifier": "t_uint256",
+                                "typeString": "uint256"
+                              }
+                            },
+                            "isConstant": false,
+                            "isLValue": true,
+                            "isPure": false,
+                            "lValueRequested": true,
+                            "nodeType": "IndexAccess",
+                            "src": "31484:30:1",
+                            "typeDescriptions": {
+                              "typeIdentifier": "t_uint256",
+                              "typeString": "uint256"
+                            }
+                          },
+                          "nodeType": "Assignment",
+                          "operator": "=",
+                          "rightHandSide": {
+                            "argumentTypes": null,
+                            "id": 1240,
+                            "name": "tokenIndex",
+                            "nodeType": "Identifier",
+                            "overloadedDeclarations": [],
+                            "referencedDeclaration": 1213,
+                            "src": "31517:10:1",
+                            "typeDescriptions": {
+                              "typeIdentifier": "t_uint256",
+                              "typeString": "uint256"
+                            }
+                          },
+                          "src": "31484:43:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_uint256",
+                            "typeString": "uint256"
+                          }
+                        },
+                        "id": 1242,
+                        "nodeType": "ExpressionStatement",
+                        "src": "31484:43:1"
+                      }
+                    ]
+                  }
+                },
+                {
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+                    "id": 1249,
+                    "isConstant": false,
+                    "isLValue": false,
+                    "isPure": false,
+                    "lValueRequested": false,
+                    "nodeType": "UnaryOperation",
+                    "operator": "--",
+                    "prefix": false,
+                    "src": "31658:27:1",
+                    "subExpression": {
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+                      "expression": {
+                        "argumentTypes": null,
+                        "baseExpression": {
+                          "argumentTypes": null,
+                          "id": 1245,
+                          "name": "_ownedTokens",
+                          "nodeType": "Identifier",
+                          "overloadedDeclarations": [],
+                          "referencedDeclaration": 981,
+                          "src": "31658:12:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_mapping$_t_address_$_t_array$_t_uint256_$dyn_storage_$",
+                            "typeString": "mapping(address => uint256[] storage ref)"
+                          }
+                        },
+                        "id": 1247,
+                        "indexExpression": {
+                          "argumentTypes": null,
+                          "id": 1246,
+                          "name": "from",
+                          "nodeType": "Identifier",
+                          "overloadedDeclarations": [],
+                          "referencedDeclaration": 1197,
+                          "src": "31671:4:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_address",
+                            "typeString": "address"
+                          }
+                        },
+                        "isConstant": false,
+                        "isLValue": true,
+                        "isPure": false,
+                        "lValueRequested": false,
+                        "nodeType": "IndexAccess",
+                        "src": "31658:18:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_array$_t_uint256_$dyn_storage",
+                          "typeString": "uint256[] storage ref"
+                        }
+                      },
+                      "id": 1248,
+                      "isConstant": false,
+                      "isLValue": true,
+                      "isPure": false,
+                      "lValueRequested": true,
+                      "memberName": "length",
+                      "nodeType": "MemberAccess",
+                      "referencedDeclaration": null,
+                      "src": "31658:25:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_uint256",
+                        "typeString": "uint256"
+                      }
+                    },
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_uint256",
+                      "typeString": "uint256"
+                    }
+                  },
+                  "id": 1250,
+                  "nodeType": "ExpressionStatement",
+                  "src": "31658:27:1"
+                }
+              ]
+            },
+            "documentation": "@dev Private function to remove a token from this extension's ownership-tracking data structures. Note that\nwhile the token is not assigned a new owner, the _ownedTokensIndex mapping is _not_ updated: this allows for\ngas optimizations e.g. when performing a transfer operation (avoiding double writes).\nThis has O(1) time complexity, but alters the order of the _ownedTokens array.\n@param from address representing the previous owner of the given token ID\n@param tokenId uint256 ID of the token to be removed from the tokens list of the given address",
+            "id": 1252,
+            "implemented": true,
+            "kind": "function",
+            "modifiers": [],
+            "name": "_removeTokenFromOwnerEnumeration",
+            "nodeType": "FunctionDefinition",
+            "parameters": {
+              "id": 1200,
+              "nodeType": "ParameterList",
+              "parameters": [
+                {
+                  "constant": false,
+                  "id": 1197,
+                  "name": "from",
+                  "nodeType": "VariableDeclaration",
+                  "scope": 1252,
+                  "src": "30815:12:1",
+                  "stateVariable": false,
+                  "storageLocation": "default",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_address",
+                    "typeString": "address"
+                  },
+                  "typeName": {
+                    "id": 1196,
+                    "name": "address",
+                    "nodeType": "ElementaryTypeName",
+                    "src": "30815:7:1",
+                    "stateMutability": "nonpayable",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_address",
+                      "typeString": "address"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                },
+                {
+                  "constant": false,
+                  "id": 1199,
+                  "name": "tokenId",
+                  "nodeType": "VariableDeclaration",
+                  "scope": 1252,
+                  "src": "30829:15:1",
+                  "stateVariable": false,
+                  "storageLocation": "default",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_uint256",
+                    "typeString": "uint256"
+                  },
+                  "typeName": {
+                    "id": 1198,
+                    "name": "uint256",
+                    "nodeType": "ElementaryTypeName",
+                    "src": "30829:7:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_uint256",
+                      "typeString": "uint256"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                }
+              ],
+              "src": "30814:31:1"
+            },
+            "returnParameters": {
+              "id": 1201,
+              "nodeType": "ParameterList",
+              "parameters": [],
+              "src": "30854:0:1"
+            },
+            "scope": 1302,
+            "src": "30773:1128:1",
+            "stateMutability": "nonpayable",
+            "superFunction": null,
+            "visibility": "private"
+          },
+          {
+            "body": {
+              "id": 1300,
+              "nodeType": "Block",
+              "src": "32260:993:1",
+              "statements": [
+                {
+                  "assignments": [
+                    1258
+                  ],
+                  "declarations": [
+                    {
+                      "constant": false,
+                      "id": 1258,
+                      "name": "lastTokenIndex",
+                      "nodeType": "VariableDeclaration",
+                      "scope": 1300,
+                      "src": "32438:22:1",
+                      "stateVariable": false,
+                      "storageLocation": "default",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_uint256",
+                        "typeString": "uint256"
+                      },
+                      "typeName": {
+                        "id": 1257,
+                        "name": "uint256",
+                        "nodeType": "ElementaryTypeName",
+                        "src": "32438:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      },
+                      "value": null,
+                      "visibility": "internal"
+                    }
+                  ],
+                  "id": 1264,
+                  "initialValue": {
+                    "argumentTypes": null,
+                    "arguments": [
+                      {
+                        "argumentTypes": null,
+                        "hexValue": "31",
+                        "id": 1262,
+                        "isConstant": false,
+                        "isLValue": false,
+                        "isPure": true,
+                        "kind": "number",
+                        "lValueRequested": false,
+                        "nodeType": "Literal",
+                        "src": "32485:1:1",
+                        "subdenomination": null,
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_rational_1_by_1",
+                          "typeString": "int_const 1"
+                        },
+                        "value": "1"
+                      }
+                    ],
+                    "expression": {
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+                            "src": "35820:7:1",
+                            "typeDescriptions": {
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+                          "name": "_exists",
+                          "nodeType": "Identifier",
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+                          "referencedDeclaration": 684,
+                          "src": "35812:7:1",
+                          "typeDescriptions": {
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+                            "typeString": "function (uint256) view returns (bool)"
+                          }
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+                        "kind": "functionCall",
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+                        "nodeType": "FunctionCall",
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+                        "typeDescriptions": {
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+                      }
+                    ],
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+                        "src": "35887:10:1",
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+                          "typeIdentifier": "t_mapping$_t_uint256_$_t_string_storage_$",
+                          "typeString": "mapping(uint256 => string storage ref)"
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+                        "src": "35898:7:1",
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+                          "typeString": "uint256"
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+                        "typeString": "string storage ref"
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+                      "typeDescriptions": {
+                        "typeIdentifier": "t_string_memory_ptr",
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+                }
+              ]
+            },
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+            "kind": "function",
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+                  "storageLocation": "default",
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+                    "name": "uint256",
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+                      "typeString": "string"
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+                  "visibility": "internal"
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+            "src": "35727:192:1",
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+            "visibility": "internal"
+          },
+          {
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+                    "arguments": [
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+                        "name": "owner",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 1419,
+                        "src": "36290:5:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        }
+                      },
+                      {
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+                        "id": 1428,
+                        "name": "tokenId",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 1421,
+                        "src": "36297:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      }
+                    ],
+                    "expression": {
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+                          "typeString": "address"
+                        },
+                        {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      ],
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+                        "id": 1424,
+                        "name": "super",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 1576,
+                        "src": "36278:5:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_super$_ERC721Metadata_$1448",
+                          "typeString": "contract super ERC721Metadata"
+                        }
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+                      "isConstant": false,
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+                      "nodeType": "MemberAccess",
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+                      "src": "36278:11:1",
+                      "typeDescriptions": {
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+                        "typeString": "function (address,uint256)"
+                      }
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+                        "arguments": [
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+                            "baseExpression": {
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+                              "id": 1432,
+                              "name": "_tokenURIs",
+                              "nodeType": "Identifier",
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+                              "referencedDeclaration": 1338,
+                              "src": "36361:10:1",
+                              "typeDescriptions": {
+                                "typeIdentifier": "t_mapping$_t_uint256_$_t_string_storage_$",
+                                "typeString": "mapping(uint256 => string storage ref)"
+                              }
+                            },
+                            "id": 1434,
+                            "indexExpression": {
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+                              "id": 1433,
+                              "name": "tokenId",
+                              "nodeType": "Identifier",
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+                              "referencedDeclaration": 1421,
+                              "src": "36372:7:1",
+                              "typeDescriptions": {
+                                "typeIdentifier": "t_uint256",
+                                "typeString": "uint256"
+                              }
+                            },
+                            "isConstant": false,
+                            "isLValue": true,
+                            "isPure": false,
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+                            "nodeType": "IndexAccess",
+                            "src": "36361:19:1",
+                            "typeDescriptions": {
+                              "typeIdentifier": "t_string_storage",
+                              "typeString": "string storage ref"
+                            }
+                          }
+                        ],
+                        "expression": {
+                          "argumentTypes": [
+                            {
+                              "typeIdentifier": "t_string_storage",
+                              "typeString": "string storage ref"
+                            }
+                          ],
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+                          "nodeType": "ElementaryTypeNameExpression",
+                          "src": "36355:5:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_type$_t_bytes_storage_ptr_$",
+                            "typeString": "type(bytes storage pointer)"
+                          },
+                          "typeName": "bytes"
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+                        "isConstant": false,
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+                        "isPure": false,
+                        "kind": "typeConversion",
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+                        "names": [],
+                        "nodeType": "FunctionCall",
+                        "src": "36355:26:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_bytes_storage_ptr",
+                          "typeString": "bytes storage pointer"
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+                      "src": "36355:33:1",
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+                        "typeString": "uint256"
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+                      "id": 1437,
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+                      "kind": "number",
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+                      "nodeType": "Literal",
+                      "src": "36392:1:1",
+                      "subdenomination": null,
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_rational_0_by_1",
+                        "typeString": "int_const 0"
+                      },
+                      "value": "0"
+                    },
+                    "src": "36355:38:1",
+                    "typeDescriptions": {
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+                      "typeString": "bool"
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+                    "nodeType": "Block",
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+                    "statements": [
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+                          "argumentTypes": null,
+                          "id": 1442,
+                          "isConstant": false,
+                          "isLValue": false,
+                          "isPure": false,
+                          "lValueRequested": false,
+                          "nodeType": "UnaryOperation",
+                          "operator": "delete",
+                          "prefix": true,
+                          "src": "36409:26:1",
+                          "subExpression": {
+                            "argumentTypes": null,
+                            "baseExpression": {
+                              "argumentTypes": null,
+                              "id": 1439,
+                              "name": "_tokenURIs",
+                              "nodeType": "Identifier",
+                              "overloadedDeclarations": [],
+                              "referencedDeclaration": 1338,
+                              "src": "36416:10:1",
+                              "typeDescriptions": {
+                                "typeIdentifier": "t_mapping$_t_uint256_$_t_string_storage_$",
+                                "typeString": "mapping(uint256 => string storage ref)"
+                              }
+                            },
+                            "id": 1441,
+                            "indexExpression": {
+                              "argumentTypes": null,
+                              "id": 1440,
+                              "name": "tokenId",
+                              "nodeType": "Identifier",
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+                              "referencedDeclaration": 1421,
+                              "src": "36427:7:1",
+                              "typeDescriptions": {
+                                "typeIdentifier": "t_uint256",
+                                "typeString": "uint256"
+                              }
+                            },
+                            "isConstant": false,
+                            "isLValue": true,
+                            "isPure": false,
+                            "lValueRequested": true,
+                            "nodeType": "IndexAccess",
+                            "src": "36416:19:1",
+                            "typeDescriptions": {
+                              "typeIdentifier": "t_string_storage",
+                              "typeString": "string storage ref"
+                            }
+                          },
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_tuple$__$",
+                            "typeString": "tuple()"
+                          }
+                        },
+                        "id": 1443,
+                        "nodeType": "ExpressionStatement",
+                        "src": "36409:26:1"
+                      }
+                    ]
+                  }
+                }
+              ]
+            },
+            "documentation": "@dev Internal function to burn a specific token.\nReverts if the token does not exist.\nDeprecated, use _burn(uint256) instead.\n@param owner owner of the token to burn\n@param tokenId uint256 ID of the token being burned by the msg.sender",
+            "id": 1447,
+            "implemented": true,
+            "kind": "function",
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+            "name": "_burn",
+            "nodeType": "FunctionDefinition",
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+                  "id": 1419,
+                  "name": "owner",
+                  "nodeType": "VariableDeclaration",
+                  "scope": 1447,
+                  "src": "36227:13:1",
+                  "stateVariable": false,
+                  "storageLocation": "default",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_address",
+                    "typeString": "address"
+                  },
+                  "typeName": {
+                    "id": 1418,
+                    "name": "address",
+                    "nodeType": "ElementaryTypeName",
+                    "src": "36227:7:1",
+                    "stateMutability": "nonpayable",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_address",
+                      "typeString": "address"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                },
+                {
+                  "constant": false,
+                  "id": 1421,
+                  "name": "tokenId",
+                  "nodeType": "VariableDeclaration",
+                  "scope": 1447,
+                  "src": "36242:15:1",
+                  "stateVariable": false,
+                  "storageLocation": "default",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_uint256",
+                    "typeString": "uint256"
+                  },
+                  "typeName": {
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+                    "name": "uint256",
+                    "nodeType": "ElementaryTypeName",
+                    "src": "36242:7:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_uint256",
+                      "typeString": "uint256"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                }
+              ],
+              "src": "36226:32:1"
+            },
+            "returnParameters": {
+              "id": 1423,
+              "nodeType": "ParameterList",
+              "parameters": [],
+              "src": "36268:0:1"
+            },
+            "scope": 1448,
+            "src": "36212:240:1",
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+                        }
+                      },
+                      {
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+                        "id": 764,
+                        "name": "tokenId",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 727,
+                        "src": "21088:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      }
+                    ],
+                    "expression": {
+                      "argumentTypes": [
+                        {
+                          "typeIdentifier": "t_address_payable",
+                          "typeString": "address payable"
+                        },
+                        {
+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        },
+                        {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      ],
+                      "id": 759,
+                      "name": "Transfer",
+                      "nodeType": "Identifier",
+                      "overloadedDeclarations": [],
+                      "referencedDeclaration": 34,
+                      "src": "21063:8:1",
+                      "typeDescriptions": {
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+                        "typeString": "function (address,address,uint256)"
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+                    "isConstant": false,
+                    "isLValue": false,
+                    "isPure": false,
+                    "kind": "functionCall",
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+                    "names": [],
+                    "nodeType": "FunctionCall",
+                    "src": "21063:33:1",
+                    "typeDescriptions": {
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+                      "typeString": "tuple()"
+                    }
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+                  "nodeType": "EmitStatement",
+                  "src": "21058:38:1"
+                }
+              ]
+            },
+            "documentation": "@dev Internal function to mint a new token.\nReverts if the given token ID already exists.\n@param to The address that will own the minted token\n@param tokenId uint256 ID of the token to be minted",
+            "id": 768,
+            "implemented": true,
+            "kind": "function",
+            "modifiers": [],
+            "name": "_mint",
+            "nodeType": "FunctionDefinition",
+            "parameters": {
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+              "nodeType": "ParameterList",
+              "parameters": [
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+                  "id": 725,
+                  "name": "to",
+                  "nodeType": "VariableDeclaration",
+                  "scope": 768,
+                  "src": "20791:10:1",
+                  "stateVariable": false,
+                  "storageLocation": "default",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_address",
+                    "typeString": "address"
+                  },
+                  "typeName": {
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+                    "name": "address",
+                    "nodeType": "ElementaryTypeName",
+                    "src": "20791:7:1",
+                    "stateMutability": "nonpayable",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_address",
+                      "typeString": "address"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                },
+                {
+                  "constant": false,
+                  "id": 727,
+                  "name": "tokenId",
+                  "nodeType": "VariableDeclaration",
+                  "scope": 768,
+                  "src": "20803:15:1",
+                  "stateVariable": false,
+                  "storageLocation": "default",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_uint256",
+                    "typeString": "uint256"
+                  },
+                  "typeName": {
+                    "id": 726,
+                    "name": "uint256",
+                    "nodeType": "ElementaryTypeName",
+                    "src": "20803:7:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_uint256",
+                      "typeString": "uint256"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                }
+              ],
+              "src": "20790:29:1"
+            },
+            "returnParameters": {
+              "id": 729,
+              "nodeType": "ParameterList",
+              "parameters": [],
+              "src": "20829:0:1"
+            },
+            "scope": 944,
+            "src": "20776:327:1",
+            "stateMutability": "nonpayable",
+            "superFunction": null,
+            "visibility": "internal"
+          },
+          {
+            "body": {
+              "id": 810,
+              "nodeType": "Block",
+              "src": "21434:268:1",
+              "statements": [
+                {
+                  "expression": {
+                    "argumentTypes": null,
+                    "arguments": [
+                      {
+                        "argumentTypes": null,
+                        "commonType": {
+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        },
+                        "id": 780,
+                        "isConstant": false,
+                        "isLValue": false,
+                        "isPure": false,
+                        "lValueRequested": false,
+                        "leftExpression": {
+                          "argumentTypes": null,
+                          "arguments": [
+                            {
+                              "argumentTypes": null,
+                              "id": 777,
+                              "name": "tokenId",
+                              "nodeType": "Identifier",
+                              "overloadedDeclarations": [],
+                              "referencedDeclaration": 772,
+                              "src": "21460:7:1",
+                              "typeDescriptions": {
+                                "typeIdentifier": "t_uint256",
+                                "typeString": "uint256"
+                              }
+                            }
+                          ],
+                          "expression": {
+                            "argumentTypes": [
+                              {
+                                "typeIdentifier": "t_uint256",
+                                "typeString": "uint256"
+                              }
+                            ],
+                            "id": 776,
+                            "name": "ownerOf",
+                            "nodeType": "Identifier",
+                            "overloadedDeclarations": [
+                              480
+                            ],
+                            "referencedDeclaration": 480,
+                            "src": "21452:7:1",
+                            "typeDescriptions": {
+                              "typeIdentifier": "t_function_internal_view$_t_uint256_$returns$_t_address_$",
+                              "typeString": "function (uint256) view returns (address)"
+                            }
+                          },
+                          "id": 778,
+                          "isConstant": false,
+                          "isLValue": false,
+                          "isPure": false,
+                          "kind": "functionCall",
+                          "lValueRequested": false,
+                          "names": [],
+                          "nodeType": "FunctionCall",
+                          "src": "21452:16:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_address",
+                            "typeString": "address"
+                          }
+                        },
+                        "nodeType": "BinaryOperation",
+                        "operator": "==",
+                        "rightExpression": {
+                          "argumentTypes": null,
+                          "id": 779,
+                          "name": "owner",
+                          "nodeType": "Identifier",
+                          "overloadedDeclarations": [],
+                          "referencedDeclaration": 770,
+                          "src": "21472:5:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_address",
+                            "typeString": "address"
+                          }
+                        },
+                        "src": "21452:25:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_bool",
+                          "typeString": "bool"
+                        }
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+                        "hexValue": "4552433732313a206275726e206f6620746f6b656e2074686174206973206e6f74206f776e",
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+                        "isConstant": false,
+                        "isLValue": false,
+                        "isPure": true,
+                        "kind": "string",
+                        "lValueRequested": false,
+                        "nodeType": "Literal",
+                        "src": "21479:39:1",
+                        "subdenomination": null,
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_stringliteral_d9af5b321f427d3820b5fc07b432b1ddf1bb6411d5d926d9de9773fd616ab5ee",
+                          "typeString": "literal_string \"ERC721: burn of token that is not own\""
+                        },
+                        "value": "ERC721: burn of token that is not own"
+                      }
+                    ],
+                    "expression": {
+                      "argumentTypes": [
+                        {
+                          "typeIdentifier": "t_bool",
+                          "typeString": "bool"
+                        },
+                        {
+                          "typeIdentifier": "t_stringliteral_d9af5b321f427d3820b5fc07b432b1ddf1bb6411d5d926d9de9773fd616ab5ee",
+                          "typeString": "literal_string \"ERC721: burn of token that is not own\""
+                        }
+                      ],
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+                      "name": "require",
+                      "nodeType": "Identifier",
+                      "overloadedDeclarations": [
+                        1543,
+                        1544
+                      ],
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+                      "src": "21444:7:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_function_require_pure$_t_bool_$_t_string_memory_ptr_$returns$__$",
+                        "typeString": "function (bool,string memory) pure"
+                      }
+                    },
+                    "id": 782,
+                    "isConstant": false,
+                    "isLValue": false,
+                    "isPure": false,
+                    "kind": "functionCall",
+                    "lValueRequested": false,
+                    "names": [],
+                    "nodeType": "FunctionCall",
+                    "src": "21444:75:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_tuple$__$",
+                      "typeString": "tuple()"
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+                  },
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+                  "nodeType": "ExpressionStatement",
+                  "src": "21444:75:1"
+                },
+                {
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+                    "arguments": [
+                      {
+                        "argumentTypes": null,
+                        "id": 785,
+                        "name": "tokenId",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 772,
+                        "src": "21545:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      }
+                    ],
+                    "expression": {
+                      "argumentTypes": [
+                        {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      ],
+                      "id": 784,
+                      "name": "_clearApproval",
+                      "nodeType": "Identifier",
+                      "overloadedDeclarations": [],
+                      "referencedDeclaration": 943,
+                      "src": "21530:14:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_function_internal_nonpayable$_t_uint256_$returns$__$",
+                        "typeString": "function (uint256)"
+                      }
+                    },
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+                    "isConstant": false,
+                    "isLValue": false,
+                    "isPure": false,
+                    "kind": "functionCall",
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+                    "names": [],
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+                    "src": "21530:23:1",
+                    "typeDescriptions": {
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+                      "typeString": "tuple()"
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+                  "nodeType": "ExpressionStatement",
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+                },
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+                      "expression": {
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+                        "baseExpression": {
+                          "argumentTypes": null,
+                          "id": 788,
+                          "name": "_ownedTokensCount",
+                          "nodeType": "Identifier",
+                          "overloadedDeclarations": [],
+                          "referencedDeclaration": 415,
+                          "src": "21564:17:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_mapping$_t_address_$_t_struct$_Counter_$296_storage_$",
+                            "typeString": "mapping(address => struct Counters.Counter storage ref)"
+                          }
+                        },
+                        "id": 790,
+                        "indexExpression": {
+                          "argumentTypes": null,
+                          "id": 789,
+                          "name": "owner",
+                          "nodeType": "Identifier",
+                          "overloadedDeclarations": [],
+                          "referencedDeclaration": 770,
+                          "src": "21582:5:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_address",
+                            "typeString": "address"
+                          }
+                        },
+                        "isConstant": false,
+                        "isLValue": true,
+                        "isPure": false,
+                        "lValueRequested": false,
+                        "nodeType": "IndexAccess",
+                        "src": "21564:24:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_struct$_Counter_$296_storage",
+                          "typeString": "struct Counters.Counter storage ref"
+                        }
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+                      "id": 791,
+                      "isConstant": false,
+                      "isLValue": true,
+                      "isPure": false,
+                      "lValueRequested": false,
+                      "memberName": "decrement",
+                      "nodeType": "MemberAccess",
+                      "referencedDeclaration": 335,
+                      "src": "21564:34:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_function_internal_nonpayable$_t_struct$_Counter_$296_storage_ptr_$returns$__$bound_to$_t_struct$_Counter_$296_storage_ptr_$",
+                        "typeString": "function (struct Counters.Counter storage pointer)"
+                      }
+                    },
+                    "id": 792,
+                    "isConstant": false,
+                    "isLValue": false,
+                    "isPure": false,
+                    "kind": "functionCall",
+                    "lValueRequested": false,
+                    "names": [],
+                    "nodeType": "FunctionCall",
+                    "src": "21564:36:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_tuple$__$",
+                      "typeString": "tuple()"
+                    }
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+                  "id": 793,
+                  "nodeType": "ExpressionStatement",
+                  "src": "21564:36:1"
+                },
+                {
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+                    "id": 800,
+                    "isConstant": false,
+                    "isLValue": false,
+                    "isPure": false,
+                    "lValueRequested": false,
+                    "leftHandSide": {
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+                      "baseExpression": {
+                        "argumentTypes": null,
+                        "id": 794,
+                        "name": "_tokenOwner",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 407,
+                        "src": "21610:11:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_mapping$_t_uint256_$_t_address_$",
+                          "typeString": "mapping(uint256 => address)"
+                        }
+                      },
+                      "id": 796,
+                      "indexExpression": {
+                        "argumentTypes": null,
+                        "id": 795,
+                        "name": "tokenId",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 772,
+                        "src": "21622:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      },
+                      "isConstant": false,
+                      "isLValue": true,
+                      "isPure": false,
+                      "lValueRequested": true,
+                      "nodeType": "IndexAccess",
+                      "src": "21610:20:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_address",
+                        "typeString": "address"
+                      }
+                    },
+                    "nodeType": "Assignment",
+                    "operator": "=",
+                    "rightHandSide": {
+                      "argumentTypes": null,
+                      "arguments": [
+                        {
+                          "argumentTypes": null,
+                          "hexValue": "30",
+                          "id": 798,
+                          "isConstant": false,
+                          "isLValue": false,
+                          "isPure": true,
+                          "kind": "number",
+                          "lValueRequested": false,
+                          "nodeType": "Literal",
+                          "src": "21641:1:1",
+                          "subdenomination": null,
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_rational_0_by_1",
+                            "typeString": "int_const 0"
+                          },
+                          "value": "0"
+                        }
+                      ],
+                      "expression": {
+                        "argumentTypes": [
+                          {
+                            "typeIdentifier": "t_rational_0_by_1",
+                            "typeString": "int_const 0"
+                          }
+                        ],
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+                        "isConstant": false,
+                        "isLValue": false,
+                        "isPure": true,
+                        "lValueRequested": false,
+                        "nodeType": "ElementaryTypeNameExpression",
+                        "src": "21633:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_type$_t_address_$",
+                          "typeString": "type(address)"
+                        },
+                        "typeName": "address"
+                      },
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+                      "isConstant": false,
+                      "isLValue": false,
+                      "isPure": true,
+                      "kind": "typeConversion",
+                      "lValueRequested": false,
+                      "names": [],
+                      "nodeType": "FunctionCall",
+                      "src": "21633:10:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_address_payable",
+                        "typeString": "address payable"
+                      }
+                    },
+                    "src": "21610:33:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_address",
+                      "typeString": "address"
+                    }
+                  },
+                  "id": 801,
+                  "nodeType": "ExpressionStatement",
+                  "src": "21610:33:1"
+                },
+                {
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+                    "arguments": [
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+                        "argumentTypes": null,
+                        "id": 803,
+                        "name": "owner",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 770,
+                        "src": "21668:5:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        }
+                      },
+                      {
+                        "argumentTypes": null,
+                        "arguments": [
+                          {
+                            "argumentTypes": null,
+                            "hexValue": "30",
+                            "id": 805,
+                            "isConstant": false,
+                            "isLValue": false,
+                            "isPure": true,
+                            "kind": "number",
+                            "lValueRequested": false,
+                            "nodeType": "Literal",
+                            "src": "21683:1:1",
+                            "subdenomination": null,
+                            "typeDescriptions": {
+                              "typeIdentifier": "t_rational_0_by_1",
+                              "typeString": "int_const 0"
+                            },
+                            "value": "0"
+                          }
+                        ],
+                        "expression": {
+                          "argumentTypes": [
+                            {
+                              "typeIdentifier": "t_rational_0_by_1",
+                              "typeString": "int_const 0"
+                            }
+                          ],
+                          "id": 804,
+                          "isConstant": false,
+                          "isLValue": false,
+                          "isPure": true,
+                          "lValueRequested": false,
+                          "nodeType": "ElementaryTypeNameExpression",
+                          "src": "21675:7:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_type$_t_address_$",
+                            "typeString": "type(address)"
+                          },
+                          "typeName": "address"
+                        },
+                        "id": 806,
+                        "isConstant": false,
+                        "isLValue": false,
+                        "isPure": true,
+                        "kind": "typeConversion",
+                        "lValueRequested": false,
+                        "names": [],
+                        "nodeType": "FunctionCall",
+                        "src": "21675:10:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_address_payable",
+                          "typeString": "address payable"
+                        }
+                      },
+                      {
+                        "argumentTypes": null,
+                        "id": 807,
+                        "name": "tokenId",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 772,
+                        "src": "21687:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      }
+                    ],
+                    "expression": {
+                      "argumentTypes": [
+                        {
+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        },
+                        {
+                          "typeIdentifier": "t_address_payable",
+                          "typeString": "address payable"
+                        },
+                        {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      ],
+                      "id": 802,
+                      "name": "Transfer",
+                      "nodeType": "Identifier",
+                      "overloadedDeclarations": [],
+                      "referencedDeclaration": 34,
+                      "src": "21659:8:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_function_event_nonpayable$_t_address_$_t_address_$_t_uint256_$returns$__$",
+                        "typeString": "function (address,address,uint256)"
+                      }
+                    },
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+                    "isConstant": false,
+                    "isLValue": false,
+                    "isPure": false,
+                    "kind": "functionCall",
+                    "lValueRequested": false,
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+                    "nodeType": "FunctionCall",
+                    "src": "21659:36:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_tuple$__$",
+                      "typeString": "tuple()"
+                    }
+                  },
+                  "id": 809,
+                  "nodeType": "EmitStatement",
+                  "src": "21654:41:1"
+                }
+              ]
+            },
+            "documentation": "@dev Internal function to burn a specific token.\nReverts if the token does not exist.\nDeprecated, use _burn(uint256) instead.\n@param owner owner of the token to burn\n@param tokenId uint256 ID of the token being burned",
+            "id": 811,
+            "implemented": true,
+            "kind": "function",
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+            "name": "_burn",
+            "nodeType": "FunctionDefinition",
+            "parameters": {
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+              "nodeType": "ParameterList",
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+                  "id": 770,
+                  "name": "owner",
+                  "nodeType": "VariableDeclaration",
+                  "scope": 811,
+                  "src": "21393:13:1",
+                  "stateVariable": false,
+                  "storageLocation": "default",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_address",
+                    "typeString": "address"
+                  },
+                  "typeName": {
+                    "id": 769,
+                    "name": "address",
+                    "nodeType": "ElementaryTypeName",
+                    "src": "21393:7:1",
+                    "stateMutability": "nonpayable",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_address",
+                      "typeString": "address"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                },
+                {
+                  "constant": false,
+                  "id": 772,
+                  "name": "tokenId",
+                  "nodeType": "VariableDeclaration",
+                  "scope": 811,
+                  "src": "21408:15:1",
+                  "stateVariable": false,
+                  "storageLocation": "default",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_uint256",
+                    "typeString": "uint256"
+                  },
+                  "typeName": {
+                    "id": 771,
+                    "name": "uint256",
+                    "nodeType": "ElementaryTypeName",
+                    "src": "21408:7:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_uint256",
+                      "typeString": "uint256"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                }
+              ],
+              "src": "21392:32:1"
+            },
+            "returnParameters": {
+              "id": 774,
+              "nodeType": "ParameterList",
+              "parameters": [],
+              "src": "21434:0:1"
+            },
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+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        },
+                        {
+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        },
+                        {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
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+                        "typeDescriptions": {
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+                          "typeString": "address payable"
+                        }
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+                          "typeString": "bytes memory"
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+                    ],
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+                          "typeIdentifier": "t_address_payable",
+                          "typeString": "address payable"
+                        },
+                        {
+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
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+                          "typeIdentifier": "t_uint256",
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+                          "name": "IERC721Receiver",
+                          "nodeType": "Identifier",
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+                          "src": "23593:15:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_type$_t_contract$_IERC721Receiver_$139_$",
+                            "typeString": "type(contract IERC721Receiver)"
+                          }
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+                            "typeIdentifier": "t_bytes4",
+                            "typeString": "bytes4"
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+                          "name": "_ERC721_RECEIVED",
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+                }
+              ]
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+                          "typeIdentifier": "t_stringliteral_d269a4e9f5820dcdb69ea21f528512eb9b927c8d846d48aa51c9219f461d4dcc",
+                          "typeString": "literal_string \"ERC721Enumerable: global index out of bounds\""
+                        }
+                      ],
+                      "id": 1044,
+                      "name": "require",
+                      "nodeType": "Identifier",
+                      "overloadedDeclarations": [
+                        1543,
+                        1544
+                      ],
+                      "referencedDeclaration": 1544,
+                      "src": "27171:7:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_function_require_pure$_t_bool_$_t_string_memory_ptr_$returns$__$",
+                        "typeString": "function (bool,string memory) pure"
+                      }
+                    },
+                    "id": 1050,
+                    "isConstant": false,
+                    "isLValue": false,
+                    "isPure": false,
+                    "kind": "functionCall",
+                    "lValueRequested": false,
+                    "names": [],
+                    "nodeType": "FunctionCall",
+                    "src": "27171:78:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_tuple$__$",
+                      "typeString": "tuple()"
+                    }
+                  },
+                  "id": 1051,
+                  "nodeType": "ExpressionStatement",
+                  "src": "27171:78:1"
+                },
+                {
+                  "expression": {
+                    "argumentTypes": null,
+                    "baseExpression": {
+                      "argumentTypes": null,
+                      "id": 1052,
+                      "name": "_allTokens",
+                      "nodeType": "Identifier",
+                      "overloadedDeclarations": [],
+                      "referencedDeclaration": 988,
+                      "src": "27266:10:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_array$_t_uint256_$dyn_storage",
+                        "typeString": "uint256[] storage ref"
+                      }
+                    },
+                    "id": 1054,
+                    "indexExpression": {
+                      "argumentTypes": null,
+                      "id": 1053,
+                      "name": "index",
+                      "nodeType": "Identifier",
+                      "overloadedDeclarations": [],
+                      "referencedDeclaration": 1039,
+                      "src": "27277:5:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_uint256",
+                        "typeString": "uint256"
+                      }
+                    },
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+                    "isLValue": true,
+                    "isPure": false,
+                    "lValueRequested": false,
+                    "nodeType": "IndexAccess",
+                    "src": "27266:17:1",
+                    "typeDescriptions": {
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+                      "typeString": "uint256"
+                    }
+                  },
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+                  "id": 1055,
+                  "nodeType": "Return",
+                  "src": "27259:24:1"
+                }
+              ]
+            },
+            "documentation": "@dev Gets the token ID at a given index of all the tokens in this contract\nReverts if the index is greater or equal to the total number of tokens.\n@param index uint256 representing the index to be accessed of the tokens list\n@return uint256 token ID at the given index of the tokens list",
+            "id": 1057,
+            "implemented": true,
+            "kind": "function",
+            "modifiers": [],
+            "name": "tokenByIndex",
+            "nodeType": "FunctionDefinition",
+            "parameters": {
+              "id": 1040,
+              "nodeType": "ParameterList",
+              "parameters": [
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+                  "constant": false,
+                  "id": 1039,
+                  "name": "index",
+                  "nodeType": "VariableDeclaration",
+                  "scope": 1057,
+                  "src": "27116:13:1",
+                  "stateVariable": false,
+                  "storageLocation": "default",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_uint256",
+                    "typeString": "uint256"
+                  },
+                  "typeName": {
+                    "id": 1038,
+                    "name": "uint256",
+                    "nodeType": "ElementaryTypeName",
+                    "src": "27116:7:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_uint256",
+                      "typeString": "uint256"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                }
+              ],
+              "src": "27115:15:1"
+            },
+            "returnParameters": {
+              "id": 1043,
+              "nodeType": "ParameterList",
+              "parameters": [
+                {
+                  "constant": false,
+                  "id": 1042,
+                  "name": "",
+                  "nodeType": "VariableDeclaration",
+                  "scope": 1057,
+                  "src": "27152:7:1",
+                  "stateVariable": false,
+                  "storageLocation": "default",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_uint256",
+                    "typeString": "uint256"
+                  },
+                  "typeName": {
+                    "id": 1041,
+                    "name": "uint256",
+                    "nodeType": "ElementaryTypeName",
+                    "src": "27152:7:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_uint256",
+                      "typeString": "uint256"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                }
+              ],
+              "src": "27151:9:1"
+            },
+            "scope": 1302,
+            "src": "27094:196:1",
+            "stateMutability": "view",
+            "superFunction": 968,
+            "visibility": "public"
+          },
+          {
+            "body": {
+              "id": 1084,
+              "nodeType": "Block",
+              "src": "27740:164:1",
+              "statements": [
+                {
+                  "expression": {
+                    "argumentTypes": null,
+                    "arguments": [
+                      {
+                        "argumentTypes": null,
+                        "id": 1069,
+                        "name": "from",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 1059,
+                        "src": "27770:4:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        }
+                      },
+                      {
+                        "argumentTypes": null,
+                        "id": 1070,
+                        "name": "to",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 1061,
+                        "src": "27776:2:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        }
+                      },
+                      {
+                        "argumentTypes": null,
+                        "id": 1071,
+                        "name": "tokenId",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 1063,
+                        "src": "27780:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      }
+                    ],
+                    "expression": {
+                      "argumentTypes": [
+                        {
+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        },
+                        {
+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        },
+                        {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      ],
+                      "expression": {
+                        "argumentTypes": null,
+                        "id": 1066,
+                        "name": "super",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 1572,
+                        "src": "27750:5:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_super$_ERC721Enumerable_$1302",
+                          "typeString": "contract super ERC721Enumerable"
+                        }
+                      },
+                      "id": 1068,
+                      "isConstant": false,
+                      "isLValue": false,
+                      "isPure": false,
+                      "lValueRequested": false,
+                      "memberName": "_transferFrom",
+                      "nodeType": "MemberAccess",
+                      "referencedDeclaration": 880,
+                      "src": "27750:19:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_function_internal_nonpayable$_t_address_$_t_address_$_t_uint256_$returns$__$",
+                        "typeString": "function (address,address,uint256)"
+                      }
+                    },
+                    "id": 1072,
+                    "isConstant": false,
+                    "isLValue": false,
+                    "isPure": false,
+                    "kind": "functionCall",
+                    "lValueRequested": false,
+                    "names": [],
+                    "nodeType": "FunctionCall",
+                    "src": "27750:38:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_tuple$__$",
+                      "typeString": "tuple()"
+                    }
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+                  "id": 1073,
+                  "nodeType": "ExpressionStatement",
+                  "src": "27750:38:1"
+                },
+                {
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+                    "argumentTypes": null,
+                    "arguments": [
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+                        "argumentTypes": null,
+                        "id": 1075,
+                        "name": "from",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 1059,
+                        "src": "27832:4:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        }
+                      },
+                      {
+                        "argumentTypes": null,
+                        "id": 1076,
+                        "name": "tokenId",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 1063,
+                        "src": "27838:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      }
+                    ],
+                    "expression": {
+                      "argumentTypes": [
+                        {
+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        },
+                        {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      ],
+                      "id": 1074,
+                      "name": "_removeTokenFromOwnerEnumeration",
+                      "nodeType": "Identifier",
+                      "overloadedDeclarations": [],
+                      "referencedDeclaration": 1252,
+                      "src": "27799:32:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_function_internal_nonpayable$_t_address_$_t_uint256_$returns$__$",
+                        "typeString": "function (address,uint256)"
+                      }
+                    },
+                    "id": 1077,
+                    "isConstant": false,
+                    "isLValue": false,
+                    "isPure": false,
+                    "kind": "functionCall",
+                    "lValueRequested": false,
+                    "names": [],
+                    "nodeType": "FunctionCall",
+                    "src": "27799:47:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_tuple$__$",
+                      "typeString": "tuple()"
+                    }
+                  },
+                  "id": 1078,
+                  "nodeType": "ExpressionStatement",
+                  "src": "27799:47:1"
+                },
+                {
+                  "expression": {
+                    "argumentTypes": null,
+                    "arguments": [
+                      {
+                        "argumentTypes": null,
+                        "id": 1080,
+                        "name": "to",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 1061,
+                        "src": "27885:2:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        }
+                      },
+                      {
+                        "argumentTypes": null,
+                        "id": 1081,
+                        "name": "tokenId",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 1063,
+                        "src": "27889:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      }
+                    ],
+                    "expression": {
+                      "argumentTypes": [
+                        {
+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        },
+                        {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      ],
+                      "id": 1079,
+                      "name": "_addTokenToOwnerEnumeration",
+                      "nodeType": "Identifier",
+                      "overloadedDeclarations": [],
+                      "referencedDeclaration": 1176,
+                      "src": "27857:27:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_function_internal_nonpayable$_t_address_$_t_uint256_$returns$__$",
+                        "typeString": "function (address,uint256)"
+                      }
+                    },
+                    "id": 1082,
+                    "isConstant": false,
+                    "isLValue": false,
+                    "isPure": false,
+                    "kind": "functionCall",
+                    "lValueRequested": false,
+                    "names": [],
+                    "nodeType": "FunctionCall",
+                    "src": "27857:40:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_tuple$__$",
+                      "typeString": "tuple()"
+                    }
+                  },
+                  "id": 1083,
+                  "nodeType": "ExpressionStatement",
+                  "src": "27857:40:1"
+                }
+              ]
+            },
+            "documentation": "@dev Internal function to transfer ownership of a given token ID to another address.\nAs opposed to transferFrom, this imposes no restrictions on msg.sender.\n@param from current owner of the token\n@param to address to receive the ownership of the given token ID\n@param tokenId uint256 ID of the token to be transferred",
+            "id": 1085,
+            "implemented": true,
+            "kind": "function",
+            "modifiers": [],
+            "name": "_transferFrom",
+            "nodeType": "FunctionDefinition",
+            "parameters": {
+              "id": 1064,
+              "nodeType": "ParameterList",
+              "parameters": [
+                {
+                  "constant": false,
+                  "id": 1059,
+                  "name": "from",
+                  "nodeType": "VariableDeclaration",
+                  "scope": 1085,
+                  "src": "27688:12:1",
+                  "stateVariable": false,
+                  "storageLocation": "default",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_address",
+                    "typeString": "address"
+                  },
+                  "typeName": {
+                    "id": 1058,
+                    "name": "address",
+                    "nodeType": "ElementaryTypeName",
+                    "src": "27688:7:1",
+                    "stateMutability": "nonpayable",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_address",
+                      "typeString": "address"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                },
+                {
+                  "constant": false,
+                  "id": 1061,
+                  "name": "to",
+                  "nodeType": "VariableDeclaration",
+                  "scope": 1085,
+                  "src": "27702:10:1",
+                  "stateVariable": false,
+                  "storageLocation": "default",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_address",
+                    "typeString": "address"
+                  },
+                  "typeName": {
+                    "id": 1060,
+                    "name": "address",
+                    "nodeType": "ElementaryTypeName",
+                    "src": "27702:7:1",
+                    "stateMutability": "nonpayable",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_address",
+                      "typeString": "address"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                },
+                {
+                  "constant": false,
+                  "id": 1063,
+                  "name": "tokenId",
+                  "nodeType": "VariableDeclaration",
+                  "scope": 1085,
+                  "src": "27714:15:1",
+                  "stateVariable": false,
+                  "storageLocation": "default",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_uint256",
+                    "typeString": "uint256"
+                  },
+                  "typeName": {
+                    "id": 1062,
+                    "name": "uint256",
+                    "nodeType": "ElementaryTypeName",
+                    "src": "27714:7:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_uint256",
+                      "typeString": "uint256"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                }
+              ],
+              "src": "27687:43:1"
+            },
+            "returnParameters": {
+              "id": 1065,
+              "nodeType": "ParameterList",
+              "parameters": [],
+              "src": "27740:0:1"
+            },
+            "scope": 1302,
+            "src": "27665:239:1",
+            "stateMutability": "nonpayable",
+            "superFunction": 880,
+            "visibility": "internal"
+          },
+          {
+            "body": {
+              "id": 1108,
+              "nodeType": "Block",
+              "src": "28214:143:1",
+              "statements": [
+                {
+                  "expression": {
+                    "argumentTypes": null,
+                    "arguments": [
+                      {
+                        "argumentTypes": null,
+                        "id": 1095,
+                        "name": "to",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 1087,
+                        "src": "28236:2:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        }
+                      },
+                      {
+                        "argumentTypes": null,
+                        "id": 1096,
+                        "name": "tokenId",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 1089,
+                        "src": "28240:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      }
+                    ],
+                    "expression": {
+                      "argumentTypes": [
+                        {
+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        },
+                        {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      ],
+                      "expression": {
+                        "argumentTypes": null,
+                        "id": 1092,
+                        "name": "super",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 1572,
+                        "src": "28224:5:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_super$_ERC721Enumerable_$1302",
+                          "typeString": "contract super ERC721Enumerable"
+                        }
+                      },
+                      "id": 1094,
+                      "isConstant": false,
+                      "isLValue": false,
+                      "isPure": false,
+                      "lValueRequested": false,
+                      "memberName": "_mint",
+                      "nodeType": "MemberAccess",
+                      "referencedDeclaration": 768,
+                      "src": "28224:11:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_function_internal_nonpayable$_t_address_$_t_uint256_$returns$__$",
+                        "typeString": "function (address,uint256)"
+                      }
+                    },
+                    "id": 1097,
+                    "isConstant": false,
+                    "isLValue": false,
+                    "isPure": false,
+                    "kind": "functionCall",
+                    "lValueRequested": false,
+                    "names": [],
+                    "nodeType": "FunctionCall",
+                    "src": "28224:24:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_tuple$__$",
+                      "typeString": "tuple()"
+                    }
+                  },
+                  "id": 1098,
+                  "nodeType": "ExpressionStatement",
+                  "src": "28224:24:1"
+                },
+                {
+                  "expression": {
+                    "argumentTypes": null,
+                    "arguments": [
+                      {
+                        "argumentTypes": null,
+                        "id": 1100,
+                        "name": "to",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 1087,
+                        "src": "28287:2:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        }
+                      },
+                      {
+                        "argumentTypes": null,
+                        "id": 1101,
+                        "name": "tokenId",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 1089,
+                        "src": "28291:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      }
+                    ],
+                    "expression": {
+                      "argumentTypes": [
+                        {
+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        },
+                        {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      ],
+                      "id": 1099,
+                      "name": "_addTokenToOwnerEnumeration",
+                      "nodeType": "Identifier",
+                      "overloadedDeclarations": [],
+                      "referencedDeclaration": 1176,
+                      "src": "28259:27:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_function_internal_nonpayable$_t_address_$_t_uint256_$returns$__$",
+                        "typeString": "function (address,uint256)"
+                      }
+                    },
+                    "id": 1102,
+                    "isConstant": false,
+                    "isLValue": false,
+                    "isPure": false,
+                    "kind": "functionCall",
+                    "lValueRequested": false,
+                    "names": [],
+                    "nodeType": "FunctionCall",
+                    "src": "28259:40:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_tuple$__$",
+                      "typeString": "tuple()"
+                    }
+                  },
+                  "id": 1103,
+                  "nodeType": "ExpressionStatement",
+                  "src": "28259:40:1"
+                },
+                {
+                  "expression": {
+                    "argumentTypes": null,
+                    "arguments": [
+                      {
+                        "argumentTypes": null,
+                        "id": 1105,
+                        "name": "tokenId",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 1089,
+                        "src": "28342:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      }
+                    ],
+                    "expression": {
+                      "argumentTypes": [
+                        {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      ],
+                      "id": 1104,
+                      "name": "_addTokenToAllTokensEnumeration",
+                      "nodeType": "Identifier",
+                      "overloadedDeclarations": [],
+                      "referencedDeclaration": 1195,
+                      "src": "28310:31:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_function_internal_nonpayable$_t_uint256_$returns$__$",
+                        "typeString": "function (uint256)"
+                      }
+                    },
+                    "id": 1106,
+                    "isConstant": false,
+                    "isLValue": false,
+                    "isPure": false,
+                    "kind": "functionCall",
+                    "lValueRequested": false,
+                    "names": [],
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+                    "src": "28310:40:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_tuple$__$",
+                      "typeString": "tuple()"
+                    }
+                  },
+                  "id": 1107,
+                  "nodeType": "ExpressionStatement",
+                  "src": "28310:40:1"
+                }
+              ]
+            },
+            "documentation": "@dev Internal function to mint a new token.\nReverts if the given token ID already exists.\n@param to address the beneficiary that will own the minted token\n@param tokenId uint256 ID of the token to be minted",
+            "id": 1109,
+            "implemented": true,
+            "kind": "function",
+            "modifiers": [],
+            "name": "_mint",
+            "nodeType": "FunctionDefinition",
+            "parameters": {
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+              "nodeType": "ParameterList",
+              "parameters": [
+                {
+                  "constant": false,
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+                  "name": "to",
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+                  "scope": 1109,
+                  "src": "28176:10:1",
+                  "stateVariable": false,
+                  "storageLocation": "default",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_address",
+                    "typeString": "address"
+                  },
+                  "typeName": {
+                    "id": 1086,
+                    "name": "address",
+                    "nodeType": "ElementaryTypeName",
+                    "src": "28176:7:1",
+                    "stateMutability": "nonpayable",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_address",
+                      "typeString": "address"
+                    }
+                  },
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+                  "visibility": "internal"
+                },
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+                  "stateVariable": false,
+                  "storageLocation": "default",
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+                    "typeString": "uint256"
+                  },
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+                      "typeString": "uint256"
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+                  "visibility": "internal"
+                }
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+            "src": "28161:196:1",
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+            "visibility": "internal"
+          },
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+              "nodeType": "Block",
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+                        "name": "owner",
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+                        "src": "28710:5:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        }
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+                        "id": 1120,
+                        "name": "tokenId",
+                        "nodeType": "Identifier",
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+                        "src": "28717:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
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+                      "argumentTypes": [
+                        {
+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        },
+                        {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
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+                        "name": "super",
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+                        "src": "28698:5:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_super$_ERC721Enumerable_$1302",
+                          "typeString": "contract super ERC721Enumerable"
+                        }
+                      },
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+                      "isConstant": false,
+                      "isLValue": false,
+                      "isPure": false,
+                      "lValueRequested": false,
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+                      "nodeType": "MemberAccess",
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+                      "src": "28698:11:1",
+                      "typeDescriptions": {
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+                        "typeString": "function (address,uint256)"
+                      }
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+                    "kind": "functionCall",
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+                    "src": "28698:27:1",
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+                        "src": "28769:5:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        }
+                      },
+                      {
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+                        "id": 1125,
+                        "name": "tokenId",
+                        "nodeType": "Identifier",
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+                        "referencedDeclaration": 1113,
+                        "src": "28776:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      }
+                    ],
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+                      "argumentTypes": [
+                        {
+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        },
+                        {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      ],
+                      "id": 1123,
+                      "name": "_removeTokenFromOwnerEnumeration",
+                      "nodeType": "Identifier",
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+                      "src": "28736:32:1",
+                      "typeDescriptions": {
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+                        "typeString": "function (address,uint256)"
+                      }
+                    },
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+                    "isConstant": false,
+                    "isLValue": false,
+                    "isPure": false,
+                    "kind": "functionCall",
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+                    "names": [],
+                    "nodeType": "FunctionCall",
+                    "src": "28736:48:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_tuple$__$",
+                      "typeString": "tuple()"
+                    }
+                  },
+                  "id": 1127,
+                  "nodeType": "ExpressionStatement",
+                  "src": "28736:48:1"
+                },
+                {
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+                    "isPure": false,
+                    "lValueRequested": false,
+                    "leftHandSide": {
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+                      "baseExpression": {
+                        "argumentTypes": null,
+                        "id": 1128,
+                        "name": "_ownedTokensIndex",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 985,
+                        "src": "28903:17:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_mapping$_t_uint256_$_t_uint256_$",
+                          "typeString": "mapping(uint256 => uint256)"
+                        }
+                      },
+                      "id": 1130,
+                      "indexExpression": {
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+                        "id": 1129,
+                        "name": "tokenId",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 1113,
+                        "src": "28921:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      },
+                      "isConstant": false,
+                      "isLValue": true,
+                      "isPure": false,
+                      "lValueRequested": true,
+                      "nodeType": "IndexAccess",
+                      "src": "28903:26:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_uint256",
+                        "typeString": "uint256"
+                      }
+                    },
+                    "nodeType": "Assignment",
+                    "operator": "=",
+                    "rightHandSide": {
+                      "argumentTypes": null,
+                      "hexValue": "30",
+                      "id": 1131,
+                      "isConstant": false,
+                      "isLValue": false,
+                      "isPure": true,
+                      "kind": "number",
+                      "lValueRequested": false,
+                      "nodeType": "Literal",
+                      "src": "28932:1:1",
+                      "subdenomination": null,
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_rational_0_by_1",
+                        "typeString": "int_const 0"
+                      },
+                      "value": "0"
+                    },
+                    "src": "28903:30:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_uint256",
+                      "typeString": "uint256"
+                    }
+                  },
+                  "id": 1133,
+                  "nodeType": "ExpressionStatement",
+                  "src": "28903:30:1"
+                },
+                {
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+                    "argumentTypes": null,
+                    "arguments": [
+                      {
+                        "argumentTypes": null,
+                        "id": 1135,
+                        "name": "tokenId",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 1113,
+                        "src": "28981:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      }
+                    ],
+                    "expression": {
+                      "argumentTypes": [
+                        {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      ],
+                      "id": 1134,
+                      "name": "_removeTokenFromAllTokensEnumeration",
+                      "nodeType": "Identifier",
+                      "overloadedDeclarations": [],
+                      "referencedDeclaration": 1301,
+                      "src": "28944:36:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_function_internal_nonpayable$_t_uint256_$returns$__$",
+                        "typeString": "function (uint256)"
+                      }
+                    },
+                    "id": 1136,
+                    "isConstant": false,
+                    "isLValue": false,
+                    "isPure": false,
+                    "kind": "functionCall",
+                    "lValueRequested": false,
+                    "names": [],
+                    "nodeType": "FunctionCall",
+                    "src": "28944:45:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_tuple$__$",
+                      "typeString": "tuple()"
+                    }
+                  },
+                  "id": 1137,
+                  "nodeType": "ExpressionStatement",
+                  "src": "28944:45:1"
+                }
+              ]
+            },
+            "documentation": "@dev Internal function to burn a specific token.\nReverts if the token does not exist.\nDeprecated, use _burn(uint256) instead.\n@param owner owner of the token to burn\n@param tokenId uint256 ID of the token being burned",
+            "id": 1139,
+            "implemented": true,
+            "kind": "function",
+            "modifiers": [],
+            "name": "_burn",
+            "nodeType": "FunctionDefinition",
+            "parameters": {
+              "id": 1114,
+              "nodeType": "ParameterList",
+              "parameters": [
+                {
+                  "constant": false,
+                  "id": 1111,
+                  "name": "owner",
+                  "nodeType": "VariableDeclaration",
+                  "scope": 1139,
+                  "src": "28647:13:1",
+                  "stateVariable": false,
+                  "storageLocation": "default",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_address",
+                    "typeString": "address"
+                  },
+                  "typeName": {
+                    "id": 1110,
+                    "name": "address",
+                    "nodeType": "ElementaryTypeName",
+                    "src": "28647:7:1",
+                    "stateMutability": "nonpayable",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_address",
+                      "typeString": "address"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                },
+                {
+                  "constant": false,
+                  "id": 1113,
+                  "name": "tokenId",
+                  "nodeType": "VariableDeclaration",
+                  "scope": 1139,
+                  "src": "28662:15:1",
+                  "stateVariable": false,
+                  "storageLocation": "default",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_uint256",
+                    "typeString": "uint256"
+                  },
+                  "typeName": {
+                    "id": 1112,
+                    "name": "uint256",
+                    "nodeType": "ElementaryTypeName",
+                    "src": "28662:7:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_uint256",
+                      "typeString": "uint256"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                }
+              ],
+              "src": "28646:32:1"
+            },
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+              "id": 1115,
+              "nodeType": "ParameterList",
+              "parameters": [],
+              "src": "28688:0:1"
+            },
+            "scope": 1302,
+            "src": "28632:364:1",
+            "stateMutability": "nonpayable",
+            "superFunction": 811,
+            "visibility": "internal"
+          },
+          {
+            "body": {
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+              "nodeType": "Block",
+              "src": "29282:43:1",
+              "statements": [
+                {
+                  "expression": {
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+                    "baseExpression": {
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+                      "id": 1147,
+                      "name": "_ownedTokens",
+                      "nodeType": "Identifier",
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+                      "referencedDeclaration": 981,
+                      "src": "29299:12:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_mapping$_t_address_$_t_array$_t_uint256_$dyn_storage_$",
+                        "typeString": "mapping(address => uint256[] storage ref)"
+                      }
+                    },
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+                      "id": 1148,
+                      "name": "owner",
+                      "nodeType": "Identifier",
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+                      "referencedDeclaration": 1141,
+                      "src": "29312:5:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_address",
+                        "typeString": "address"
+                      }
+                    },
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+                    "isLValue": true,
+                    "isPure": false,
+                    "lValueRequested": false,
+                    "nodeType": "IndexAccess",
+                    "src": "29299:19:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_array$_t_uint256_$dyn_storage",
+                      "typeString": "uint256[] storage ref"
+                    }
+                  },
+                  "functionReturnParameters": 1146,
+                  "id": 1150,
+                  "nodeType": "Return",
+                  "src": "29292:26:1"
+                }
+              ]
+            },
+            "documentation": "@dev Gets the list of token IDs of the requested owner.\n@param owner address owning the tokens\n@return uint256[] List of token IDs owned by the requested address",
+            "id": 1152,
+            "implemented": true,
+            "kind": "function",
+            "modifiers": [],
+            "name": "_tokensOfOwner",
+            "nodeType": "FunctionDefinition",
+            "parameters": {
+              "id": 1142,
+              "nodeType": "ParameterList",
+              "parameters": [
+                {
+                  "constant": false,
+                  "id": 1141,
+                  "name": "owner",
+                  "nodeType": "VariableDeclaration",
+                  "scope": 1152,
+                  "src": "29225:13:1",
+                  "stateVariable": false,
+                  "storageLocation": "default",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_address",
+                    "typeString": "address"
+                  },
+                  "typeName": {
+                    "id": 1140,
+                    "name": "address",
+                    "nodeType": "ElementaryTypeName",
+                    "src": "29225:7:1",
+                    "stateMutability": "nonpayable",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_address",
+                      "typeString": "address"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                }
+              ],
+              "src": "29224:15:1"
+            },
+            "returnParameters": {
+              "id": 1146,
+              "nodeType": "ParameterList",
+              "parameters": [
+                {
+                  "constant": false,
+                  "id": 1145,
+                  "name": "",
+                  "nodeType": "VariableDeclaration",
+                  "scope": 1152,
+                  "src": "29263:17:1",
+                  "stateVariable": false,
+                  "storageLocation": "storage",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_array$_t_uint256_$dyn_storage_ptr",
+                    "typeString": "uint256[]"
+                  },
+                  "typeName": {
+                    "baseType": {
+                      "id": 1143,
+                      "name": "uint256",
+                      "nodeType": "ElementaryTypeName",
+                      "src": "29263:7:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_uint256",
+                        "typeString": "uint256"
+                      }
+                    },
+                    "id": 1144,
+                    "length": null,
+                    "nodeType": "ArrayTypeName",
+                    "src": "29263:9:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_array$_t_uint256_$dyn_storage_ptr",
+                      "typeString": "uint256[]"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                }
+              ],
+              "src": "29262:19:1"
+            },
+            "scope": 1302,
+            "src": "29201:124:1",
+            "stateMutability": "view",
+            "superFunction": null,
+            "visibility": "internal"
+          },
+          {
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+              "nodeType": "Block",
+              "src": "29693:109:1",
+              "statements": [
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+                    "id": 1166,
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+                    "leftHandSide": {
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+                        "argumentTypes": null,
+                        "id": 1159,
+                        "name": "_ownedTokensIndex",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 985,
+                        "src": "29703:17:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_mapping$_t_uint256_$_t_uint256_$",
+                          "typeString": "mapping(uint256 => uint256)"
+                        }
+                      },
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+                      "indexExpression": {
+                        "argumentTypes": null,
+                        "id": 1160,
+                        "name": "tokenId",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 1156,
+                        "src": "29721:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
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+                      "isLValue": true,
+                      "isPure": false,
+                      "lValueRequested": true,
+                      "nodeType": "IndexAccess",
+                      "src": "29703:26:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_uint256",
+                        "typeString": "uint256"
+                      }
+                    },
+                    "nodeType": "Assignment",
+                    "operator": "=",
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+                      "argumentTypes": null,
+                      "expression": {
+                        "argumentTypes": null,
+                        "baseExpression": {
+                          "argumentTypes": null,
+                          "id": 1162,
+                          "name": "_ownedTokens",
+                          "nodeType": "Identifier",
+                          "overloadedDeclarations": [],
+                          "referencedDeclaration": 981,
+                          "src": "29732:12:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_mapping$_t_address_$_t_array$_t_uint256_$dyn_storage_$",
+                            "typeString": "mapping(address => uint256[] storage ref)"
+                          }
+                        },
+                        "id": 1164,
+                        "indexExpression": {
+                          "argumentTypes": null,
+                          "id": 1163,
+                          "name": "to",
+                          "nodeType": "Identifier",
+                          "overloadedDeclarations": [],
+                          "referencedDeclaration": 1154,
+                          "src": "29745:2:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_address",
+                            "typeString": "address"
+                          }
+                        },
+                        "isConstant": false,
+                        "isLValue": true,
+                        "isPure": false,
+                        "lValueRequested": false,
+                        "nodeType": "IndexAccess",
+                        "src": "29732:16:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_array$_t_uint256_$dyn_storage",
+                          "typeString": "uint256[] storage ref"
+                        }
+                      },
+                      "id": 1165,
+                      "isConstant": false,
+                      "isLValue": true,
+                      "isPure": false,
+                      "lValueRequested": false,
+                      "memberName": "length",
+                      "nodeType": "MemberAccess",
+                      "referencedDeclaration": null,
+                      "src": "29732:23:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_uint256",
+                        "typeString": "uint256"
+                      }
+                    },
+                    "src": "29703:52:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_uint256",
+                      "typeString": "uint256"
+                    }
+                  },
+                  "id": 1167,
+                  "nodeType": "ExpressionStatement",
+                  "src": "29703:52:1"
+                },
+                {
+                  "expression": {
+                    "argumentTypes": null,
+                    "arguments": [
+                      {
+                        "argumentTypes": null,
+                        "id": 1172,
+                        "name": "tokenId",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 1156,
+                        "src": "29787:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      }
+                    ],
+                    "expression": {
+                      "argumentTypes": [
+                        {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      ],
+                      "expression": {
+                        "argumentTypes": null,
+                        "baseExpression": {
+                          "argumentTypes": null,
+                          "id": 1168,
+                          "name": "_ownedTokens",
+                          "nodeType": "Identifier",
+                          "overloadedDeclarations": [],
+                          "referencedDeclaration": 981,
+                          "src": "29765:12:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_mapping$_t_address_$_t_array$_t_uint256_$dyn_storage_$",
+                            "typeString": "mapping(address => uint256[] storage ref)"
+                          }
+                        },
+                        "id": 1170,
+                        "indexExpression": {
+                          "argumentTypes": null,
+                          "id": 1169,
+                          "name": "to",
+                          "nodeType": "Identifier",
+                          "overloadedDeclarations": [],
+                          "referencedDeclaration": 1154,
+                          "src": "29778:2:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_address",
+                            "typeString": "address"
+                          }
+                        },
+                        "isConstant": false,
+                        "isLValue": true,
+                        "isPure": false,
+                        "lValueRequested": false,
+                        "nodeType": "IndexAccess",
+                        "src": "29765:16:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_array$_t_uint256_$dyn_storage",
+                          "typeString": "uint256[] storage ref"
+                        }
+                      },
+                      "id": 1171,
+                      "isConstant": false,
+                      "isLValue": false,
+                      "isPure": false,
+                      "lValueRequested": false,
+                      "memberName": "push",
+                      "nodeType": "MemberAccess",
+                      "referencedDeclaration": null,
+                      "src": "29765:21:1",
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+                              "lValueRequested": false,
+                              "nodeType": "IndexAccess",
+                              "src": "31368:18:1",
+                              "typeDescriptions": {
+                                "typeIdentifier": "t_array$_t_uint256_$dyn_storage",
+                                "typeString": "uint256[] storage ref"
+                              }
+                            },
+                            "id": 1233,
+                            "indexExpression": {
+                              "argumentTypes": null,
+                              "id": 1231,
+                              "name": "tokenIndex",
+                              "nodeType": "Identifier",
+                              "overloadedDeclarations": [],
+                              "referencedDeclaration": 1213,
+                              "src": "31387:10:1",
+                              "typeDescriptions": {
+                                "typeIdentifier": "t_uint256",
+                                "typeString": "uint256"
+                              }
+                            },
+                            "isConstant": false,
+                            "isLValue": true,
+                            "isPure": false,
+                            "lValueRequested": true,
+                            "nodeType": "IndexAccess",
+                            "src": "31368:30:1",
+                            "typeDescriptions": {
+                              "typeIdentifier": "t_uint256",
+                              "typeString": "uint256"
+                            }
+                          },
+                          "nodeType": "Assignment",
+                          "operator": "=",
+                          "rightHandSide": {
+                            "argumentTypes": null,
+                            "id": 1234,
+                            "name": "lastTokenId",
+                            "nodeType": "Identifier",
+                            "overloadedDeclarations": [],
+                            "referencedDeclaration": 1222,
+                            "src": "31401:11:1",
+                            "typeDescriptions": {
+                              "typeIdentifier": "t_uint256",
+                              "typeString": "uint256"
+                            }
+                          },
+                          "src": "31368:44:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_uint256",
+                            "typeString": "uint256"
+                          }
+                        },
+                        "id": 1236,
+                        "nodeType": "ExpressionStatement",
+                        "src": "31368:44:1"
+                      },
+                      {
+                        "expression": {
+                          "argumentTypes": null,
+                          "id": 1241,
+                          "isConstant": false,
+                          "isLValue": false,
+                          "isPure": false,
+                          "lValueRequested": false,
+                          "leftHandSide": {
+                            "argumentTypes": null,
+                            "baseExpression": {
+                              "argumentTypes": null,
+                              "id": 1237,
+                              "name": "_ownedTokensIndex",
+                              "nodeType": "Identifier",
+                              "overloadedDeclarations": [],
+                              "referencedDeclaration": 985,
+                              "src": "31484:17:1",
+                              "typeDescriptions": {
+                                "typeIdentifier": "t_mapping$_t_uint256_$_t_uint256_$",
+                                "typeString": "mapping(uint256 => uint256)"
+                              }
+                            },
+                            "id": 1239,
+                            "indexExpression": {
+                              "argumentTypes": null,
+                              "id": 1238,
+                              "name": "lastTokenId",
+                              "nodeType": "Identifier",
+                              "overloadedDeclarations": [],
+                              "referencedDeclaration": 1222,
+                              "src": "31502:11:1",
+                              "typeDescriptions": {
+                                "typeIdentifier": "t_uint256",
+                                "typeString": "uint256"
+                              }
+                            },
+                            "isConstant": false,
+                            "isLValue": true,
+                            "isPure": false,
+                            "lValueRequested": true,
+                            "nodeType": "IndexAccess",
+                            "src": "31484:30:1",
+                            "typeDescriptions": {
+                              "typeIdentifier": "t_uint256",
+                              "typeString": "uint256"
+                            }
+                          },
+                          "nodeType": "Assignment",
+                          "operator": "=",
+                          "rightHandSide": {
+                            "argumentTypes": null,
+                            "id": 1240,
+                            "name": "tokenIndex",
+                            "nodeType": "Identifier",
+                            "overloadedDeclarations": [],
+                            "referencedDeclaration": 1213,
+                            "src": "31517:10:1",
+                            "typeDescriptions": {
+                              "typeIdentifier": "t_uint256",
+                              "typeString": "uint256"
+                            }
+                          },
+                          "src": "31484:43:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_uint256",
+                            "typeString": "uint256"
+                          }
+                        },
+                        "id": 1242,
+                        "nodeType": "ExpressionStatement",
+                        "src": "31484:43:1"
+                      }
+                    ]
+                  }
+                },
+                {
+                  "expression": {
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+                    "id": 1249,
+                    "isConstant": false,
+                    "isLValue": false,
+                    "isPure": false,
+                    "lValueRequested": false,
+                    "nodeType": "UnaryOperation",
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+                    "prefix": false,
+                    "src": "31658:27:1",
+                    "subExpression": {
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+                      "expression": {
+                        "argumentTypes": null,
+                        "baseExpression": {
+                          "argumentTypes": null,
+                          "id": 1245,
+                          "name": "_ownedTokens",
+                          "nodeType": "Identifier",
+                          "overloadedDeclarations": [],
+                          "referencedDeclaration": 981,
+                          "src": "31658:12:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_mapping$_t_address_$_t_array$_t_uint256_$dyn_storage_$",
+                            "typeString": "mapping(address => uint256[] storage ref)"
+                          }
+                        },
+                        "id": 1247,
+                        "indexExpression": {
+                          "argumentTypes": null,
+                          "id": 1246,
+                          "name": "from",
+                          "nodeType": "Identifier",
+                          "overloadedDeclarations": [],
+                          "referencedDeclaration": 1197,
+                          "src": "31671:4:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_address",
+                            "typeString": "address"
+                          }
+                        },
+                        "isConstant": false,
+                        "isLValue": true,
+                        "isPure": false,
+                        "lValueRequested": false,
+                        "nodeType": "IndexAccess",
+                        "src": "31658:18:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_array$_t_uint256_$dyn_storage",
+                          "typeString": "uint256[] storage ref"
+                        }
+                      },
+                      "id": 1248,
+                      "isConstant": false,
+                      "isLValue": true,
+                      "isPure": false,
+                      "lValueRequested": true,
+                      "memberName": "length",
+                      "nodeType": "MemberAccess",
+                      "referencedDeclaration": null,
+                      "src": "31658:25:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_uint256",
+                        "typeString": "uint256"
+                      }
+                    },
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_uint256",
+                      "typeString": "uint256"
+                    }
+                  },
+                  "id": 1250,
+                  "nodeType": "ExpressionStatement",
+                  "src": "31658:27:1"
+                }
+              ]
+            },
+            "documentation": "@dev Private function to remove a token from this extension's ownership-tracking data structures. Note that\nwhile the token is not assigned a new owner, the _ownedTokensIndex mapping is _not_ updated: this allows for\ngas optimizations e.g. when performing a transfer operation (avoiding double writes).\nThis has O(1) time complexity, but alters the order of the _ownedTokens array.\n@param from address representing the previous owner of the given token ID\n@param tokenId uint256 ID of the token to be removed from the tokens list of the given address",
+            "id": 1252,
+            "implemented": true,
+            "kind": "function",
+            "modifiers": [],
+            "name": "_removeTokenFromOwnerEnumeration",
+            "nodeType": "FunctionDefinition",
+            "parameters": {
+              "id": 1200,
+              "nodeType": "ParameterList",
+              "parameters": [
+                {
+                  "constant": false,
+                  "id": 1197,
+                  "name": "from",
+                  "nodeType": "VariableDeclaration",
+                  "scope": 1252,
+                  "src": "30815:12:1",
+                  "stateVariable": false,
+                  "storageLocation": "default",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_address",
+                    "typeString": "address"
+                  },
+                  "typeName": {
+                    "id": 1196,
+                    "name": "address",
+                    "nodeType": "ElementaryTypeName",
+                    "src": "30815:7:1",
+                    "stateMutability": "nonpayable",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_address",
+                      "typeString": "address"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                },
+                {
+                  "constant": false,
+                  "id": 1199,
+                  "name": "tokenId",
+                  "nodeType": "VariableDeclaration",
+                  "scope": 1252,
+                  "src": "30829:15:1",
+                  "stateVariable": false,
+                  "storageLocation": "default",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_uint256",
+                    "typeString": "uint256"
+                  },
+                  "typeName": {
+                    "id": 1198,
+                    "name": "uint256",
+                    "nodeType": "ElementaryTypeName",
+                    "src": "30829:7:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_uint256",
+                      "typeString": "uint256"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                }
+              ],
+              "src": "30814:31:1"
+            },
+            "returnParameters": {
+              "id": 1201,
+              "nodeType": "ParameterList",
+              "parameters": [],
+              "src": "30854:0:1"
+            },
+            "scope": 1302,
+            "src": "30773:1128:1",
+            "stateMutability": "nonpayable",
+            "superFunction": null,
+            "visibility": "private"
+          },
+          {
+            "body": {
+              "id": 1300,
+              "nodeType": "Block",
+              "src": "32260:993:1",
+              "statements": [
+                {
+                  "assignments": [
+                    1258
+                  ],
+                  "declarations": [
+                    {
+                      "constant": false,
+                      "id": 1258,
+                      "name": "lastTokenIndex",
+                      "nodeType": "VariableDeclaration",
+                      "scope": 1300,
+                      "src": "32438:22:1",
+                      "stateVariable": false,
+                      "storageLocation": "default",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_uint256",
+                        "typeString": "uint256"
+                      },
+                      "typeName": {
+                        "id": 1257,
+                        "name": "uint256",
+                        "nodeType": "ElementaryTypeName",
+                        "src": "32438:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      },
+                      "value": null,
+                      "visibility": "internal"
+                    }
+                  ],
+                  "id": 1264,
+                  "initialValue": {
+                    "argumentTypes": null,
+                    "arguments": [
+                      {
+                        "argumentTypes": null,
+                        "hexValue": "31",
+                        "id": 1262,
+                        "isConstant": false,
+                        "isLValue": false,
+                        "isPure": true,
+                        "kind": "number",
+                        "lValueRequested": false,
+                        "nodeType": "Literal",
+                        "src": "32485:1:1",
+                        "subdenomination": null,
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_rational_1_by_1",
+                          "typeString": "int_const 1"
+                        },
+                        "value": "1"
+                      }
+                    ],
+                    "expression": {
+                      "argumentTypes": [
+                        {
+                          "typeIdentifier": "t_rational_1_by_1",
+                          "typeString": "int_const 1"
+                        }
+                      ],
+                      "expression": {
+                        "argumentTypes": null,
+                        "expression": {
+                          "argumentTypes": null,
+                          "id": 1259,
+                          "name": "_allTokens",
+                          "nodeType": "Identifier",
+                          "overloadedDeclarations": [],
+                          "referencedDeclaration": 988,
+                          "src": "32463:10:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_array$_t_uint256_$dyn_storage",
+                            "typeString": "uint256[] storage ref"
+                          }
+                        },
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+                        "isConstant": false,
+                        "isLValue": true,
+                        "isPure": false,
+                        "lValueRequested": false,
+                        "memberName": "length",
+                        "nodeType": "MemberAccess",
+                        "referencedDeclaration": null,
+                        "src": "32463:17:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      },
+                      "id": 1261,
+                      "isConstant": false,
+                      "isLValue": false,
+                      "isPure": false,
+                      "lValueRequested": false,
+                      "memberName": "sub",
+                      "nodeType": "MemberAccess",
+                      "referencedDeclaration": 190,
+                      "src": "32463:21:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_function_internal_pure$_t_uint256_$_t_uint256_$returns$_t_uint256_$bound_to$_t_uint256_$",
+                        "typeString": "function (uint256,uint256) pure returns (uint256)"
+                      }
+                    },
+                    "id": 1263,
+                    "isConstant": false,
+                    "isLValue": false,
+                    "isPure": false,
+                    "kind": "functionCall",
+                    "lValueRequested": false,
+                    "names": [],
+                    "nodeType": "FunctionCall",
+                    "src": "32463:24:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_uint256",
+                      "typeString": "uint256"
+                    }
+                  },
+                  "nodeType": "VariableDeclarationStatement",
+                  "src": "32438:49:1"
+                },
+                {
+                  "assignments": [
+                    1266
+                  ],
+                  "declarations": [
+                    {
+                      "constant": false,
+                      "id": 1266,
+                      "name": "tokenIndex",
+                      "nodeType": "VariableDeclaration",
+                      "scope": 1300,
+                      "src": "32497:18:1",
+                      "stateVariable": false,
+                      "storageLocation": "default",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_uint256",
+                        "typeString": "uint256"
+                      },
+                      "typeName": {
+                        "id": 1265,
+                        "name": "uint256",
+                        "nodeType": "ElementaryTypeName",
+                        "src": "32497:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      },
+                      "value": null,
+                      "visibility": "internal"
+                    }
+                  ],
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+                  "initialValue": {
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+                    "baseExpression": {
+                      "argumentTypes": null,
+                      "id": 1267,
+                      "name": "_allTokensIndex",
+                      "nodeType": "Identifier",
+                      "overloadedDeclarations": [],
+                      "referencedDeclaration": 992,
+                      "src": "32518:15:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_mapping$_t_uint256_$_t_uint256_$",
+                        "typeString": "mapping(uint256 => uint256)"
+                      }
+                    },
+                    "id": 1269,
+                    "indexExpression": {
+                      "argumentTypes": null,
+                      "id": 1268,
+                      "name": "tokenId",
+                      "nodeType": "Identifier",
+                      "overloadedDeclarations": [],
+                      "referencedDeclaration": 1254,
+                      "src": "32534:7:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_uint256",
+                        "typeString": "uint256"
+                      }
+                    },
+                    "isConstant": false,
+                    "isLValue": true,
+                    "isPure": false,
+                    "lValueRequested": false,
+                    "nodeType": "IndexAccess",
+                    "src": "32518:24:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_uint256",
+                      "typeString": "uint256"
+                    }
+                  },
+                  "nodeType": "VariableDeclarationStatement",
+                  "src": "32497:45:1"
+                },
+                {
+                  "assignments": [
+                    1272
+                  ],
+                  "declarations": [
+                    {
+                      "constant": false,
+                      "id": 1272,
+                      "name": "lastTokenId",
+                      "nodeType": "VariableDeclaration",
+                      "scope": 1300,
+                      "src": "32864:19:1",
+                      "stateVariable": false,
+                      "storageLocation": "default",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_uint256",
+                        "typeString": "uint256"
+                      },
+                      "typeName": {
+                        "id": 1271,
+                        "name": "uint256",
+                        "nodeType": "ElementaryTypeName",
+                        "src": "32864:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      },
+                      "value": null,
+                      "visibility": "internal"
+                    }
+                  ],
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+                  "initialValue": {
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+                    "baseExpression": {
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+                      "id": 1273,
+                      "name": "_allTokens",
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+                      "src": "32886:10:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_array$_t_uint256_$dyn_storage",
+                        "typeString": "uint256[] storage ref"
+                      }
+                    },
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+                    "indexExpression": {
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+                      "id": 1274,
+                      "name": "lastTokenIndex",
+                      "nodeType": "Identifier",
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+                      "src": "32897:14:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_uint256",
+                        "typeString": "uint256"
+                      }
+                    },
+                    "isConstant": false,
+                    "isLValue": true,
+                    "isPure": false,
+                    "lValueRequested": false,
+                    "nodeType": "IndexAccess",
+                    "src": "32886:26:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_uint256",
+                      "typeString": "uint256"
+                    }
+                  },
+                  "nodeType": "VariableDeclarationStatement",
+                  "src": "32864:48:1"
+                },
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+                        "name": "_allTokens",
+                        "nodeType": "Identifier",
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+                        "referencedDeclaration": 988,
+                        "src": "32923:10:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_array$_t_uint256_$dyn_storage",
+                          "typeString": "uint256[] storage ref"
+                        }
+                      },
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+                      "indexExpression": {
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+                        "name": "tokenIndex",
+                        "nodeType": "Identifier",
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+                        "src": "32934:10:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
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+                      "lValueRequested": true,
+                      "nodeType": "IndexAccess",
+                      "src": "32923:22:1",
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+                        "typeIdentifier": "t_uint256",
+                        "typeString": "uint256"
+                      }
+                    },
+                    "nodeType": "Assignment",
+                    "operator": "=",
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+                      "id": 1280,
+                      "name": "lastTokenId",
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+                      "overloadedDeclarations": [],
+                      "referencedDeclaration": 1272,
+                      "src": "32948:11:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_uint256",
+                        "typeString": "uint256"
+                      }
+                    },
+                    "src": "32923:36:1",
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+                      "typeString": "uint256"
+                    }
+                  },
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+                        "name": "_allTokensIndex",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 992,
+                        "src": "33027:15:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_mapping$_t_uint256_$_t_uint256_$",
+                          "typeString": "mapping(uint256 => uint256)"
+                        }
+                      },
+                      "id": 1285,
+                      "indexExpression": {
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+                        "name": "lastTokenId",
+                        "nodeType": "Identifier",
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+                        "src": "33043:11:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
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+                      "src": "33058:10:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_uint256",
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+                    }
+                  },
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+                        "src": "33189:10:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_array$_t_uint256_$dyn_storage",
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+                      "isLValue": true,
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+                        "referencedDeclaration": 1419,
+                        "src": "36290:5:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        }
+                      },
+                      {
+                        "argumentTypes": null,
+                        "id": 1428,
+                        "name": "tokenId",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 1421,
+                        "src": "36297:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      }
+                    ],
+                    "expression": {
+                      "argumentTypes": [
+                        {
+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        },
+                        {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      ],
+                      "expression": {
+                        "argumentTypes": null,
+                        "id": 1424,
+                        "name": "super",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 1576,
+                        "src": "36278:5:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_super$_ERC721Metadata_$1448",
+                          "typeString": "contract super ERC721Metadata"
+                        }
+                      },
+                      "id": 1426,
+                      "isConstant": false,
+                      "isLValue": false,
+                      "isPure": false,
+                      "lValueRequested": false,
+                      "memberName": "_burn",
+                      "nodeType": "MemberAccess",
+                      "referencedDeclaration": 811,
+                      "src": "36278:11:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_function_internal_nonpayable$_t_address_$_t_uint256_$returns$__$",
+                        "typeString": "function (address,uint256)"
+                      }
+                    },
+                    "id": 1429,
+                    "isConstant": false,
+                    "isLValue": false,
+                    "isPure": false,
+                    "kind": "functionCall",
+                    "lValueRequested": false,
+                    "names": [],
+                    "nodeType": "FunctionCall",
+                    "src": "36278:27:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_tuple$__$",
+                      "typeString": "tuple()"
+                    }
+                  },
+                  "id": 1430,
+                  "nodeType": "ExpressionStatement",
+                  "src": "36278:27:1"
+                },
+                {
+                  "condition": {
+                    "argumentTypes": null,
+                    "commonType": {
+                      "typeIdentifier": "t_uint256",
+                      "typeString": "uint256"
+                    },
+                    "id": 1438,
+                    "isConstant": false,
+                    "isLValue": false,
+                    "isPure": false,
+                    "lValueRequested": false,
+                    "leftExpression": {
+                      "argumentTypes": null,
+                      "expression": {
+                        "argumentTypes": null,
+                        "arguments": [
+                          {
+                            "argumentTypes": null,
+                            "baseExpression": {
+                              "argumentTypes": null,
+                              "id": 1432,
+                              "name": "_tokenURIs",
+                              "nodeType": "Identifier",
+                              "overloadedDeclarations": [],
+                              "referencedDeclaration": 1338,
+                              "src": "36361:10:1",
+                              "typeDescriptions": {
+                                "typeIdentifier": "t_mapping$_t_uint256_$_t_string_storage_$",
+                                "typeString": "mapping(uint256 => string storage ref)"
+                              }
+                            },
+                            "id": 1434,
+                            "indexExpression": {
+                              "argumentTypes": null,
+                              "id": 1433,
+                              "name": "tokenId",
+                              "nodeType": "Identifier",
+                              "overloadedDeclarations": [],
+                              "referencedDeclaration": 1421,
+                              "src": "36372:7:1",
+                              "typeDescriptions": {
+                                "typeIdentifier": "t_uint256",
+                                "typeString": "uint256"
+                              }
+                            },
+                            "isConstant": false,
+                            "isLValue": true,
+                            "isPure": false,
+                            "lValueRequested": false,
+                            "nodeType": "IndexAccess",
+                            "src": "36361:19:1",
+                            "typeDescriptions": {
+                              "typeIdentifier": "t_string_storage",
+                              "typeString": "string storage ref"
+                            }
+                          }
+                        ],
+                        "expression": {
+                          "argumentTypes": [
+                            {
+                              "typeIdentifier": "t_string_storage",
+                              "typeString": "string storage ref"
+                            }
+                          ],
+                          "id": 1431,
+                          "isConstant": false,
+                          "isLValue": false,
+                          "isPure": true,
+                          "lValueRequested": false,
+                          "nodeType": "ElementaryTypeNameExpression",
+                          "src": "36355:5:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_type$_t_bytes_storage_ptr_$",
+                            "typeString": "type(bytes storage pointer)"
+                          },
+                          "typeName": "bytes"
+                        },
+                        "id": 1435,
+                        "isConstant": false,
+                        "isLValue": false,
+                        "isPure": false,
+                        "kind": "typeConversion",
+                        "lValueRequested": false,
+                        "names": [],
+                        "nodeType": "FunctionCall",
+                        "src": "36355:26:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_bytes_storage_ptr",
+                          "typeString": "bytes storage pointer"
+                        }
+                      },
+                      "id": 1436,
+                      "isConstant": false,
+                      "isLValue": true,
+                      "isPure": false,
+                      "lValueRequested": false,
+                      "memberName": "length",
+                      "nodeType": "MemberAccess",
+                      "referencedDeclaration": null,
+                      "src": "36355:33:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_uint256",
+                        "typeString": "uint256"
+                      }
+                    },
+                    "nodeType": "BinaryOperation",
+                    "operator": "!=",
+                    "rightExpression": {
+                      "argumentTypes": null,
+                      "hexValue": "30",
+                      "id": 1437,
+                      "isConstant": false,
+                      "isLValue": false,
+                      "isPure": true,
+                      "kind": "number",
+                      "lValueRequested": false,
+                      "nodeType": "Literal",
+                      "src": "36392:1:1",
+                      "subdenomination": null,
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_rational_0_by_1",
+                        "typeString": "int_const 0"
+                      },
+                      "value": "0"
+                    },
+                    "src": "36355:38:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_bool",
+                      "typeString": "bool"
+                    }
+                  },
+                  "falseBody": null,
+                  "id": 1445,
+                  "nodeType": "IfStatement",
+                  "src": "36351:95:1",
+                  "trueBody": {
+                    "id": 1444,
+                    "nodeType": "Block",
+                    "src": "36395:51:1",
+                    "statements": [
+                      {
+                        "expression": {
+                          "argumentTypes": null,
+                          "id": 1442,
+                          "isConstant": false,
+                          "isLValue": false,
+                          "isPure": false,
+                          "lValueRequested": false,
+                          "nodeType": "UnaryOperation",
+                          "operator": "delete",
+                          "prefix": true,
+                          "src": "36409:26:1",
+                          "subExpression": {
+                            "argumentTypes": null,
+                            "baseExpression": {
+                              "argumentTypes": null,
+                              "id": 1439,
+                              "name": "_tokenURIs",
+                              "nodeType": "Identifier",
+                              "overloadedDeclarations": [],
+                              "referencedDeclaration": 1338,
+                              "src": "36416:10:1",
+                              "typeDescriptions": {
+                                "typeIdentifier": "t_mapping$_t_uint256_$_t_string_storage_$",
+                                "typeString": "mapping(uint256 => string storage ref)"
+                              }
+                            },
+                            "id": 1441,
+                            "indexExpression": {
+                              "argumentTypes": null,
+                              "id": 1440,
+                              "name": "tokenId",
+                              "nodeType": "Identifier",
+                              "overloadedDeclarations": [],
+                              "referencedDeclaration": 1421,
+                              "src": "36427:7:1",
+                              "typeDescriptions": {
+                                "typeIdentifier": "t_uint256",
+                                "typeString": "uint256"
+                              }
+                            },
+                            "isConstant": false,
+                            "isLValue": true,
+                            "isPure": false,
+                            "lValueRequested": true,
+                            "nodeType": "IndexAccess",
+                            "src": "36416:19:1",
+                            "typeDescriptions": {
+                              "typeIdentifier": "t_string_storage",
+                              "typeString": "string storage ref"
+                            }
+                          },
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_tuple$__$",
+                            "typeString": "tuple()"
+                          }
+                        },
+                        "id": 1443,
+                        "nodeType": "ExpressionStatement",
+                        "src": "36409:26:1"
+                      }
+                    ]
+                  }
+                }
+              ]
+            },
+            "documentation": "@dev Internal function to burn a specific token.\nReverts if the token does not exist.\nDeprecated, use _burn(uint256) instead.\n@param owner owner of the token to burn\n@param tokenId uint256 ID of the token being burned by the msg.sender",
+            "id": 1447,
+            "implemented": true,
+            "kind": "function",
+            "modifiers": [],
+            "name": "_burn",
+            "nodeType": "FunctionDefinition",
+            "parameters": {
+              "id": 1422,
+              "nodeType": "ParameterList",
+              "parameters": [
+                {
+                  "constant": false,
+                  "id": 1419,
+                  "name": "owner",
+                  "nodeType": "VariableDeclaration",
+                  "scope": 1447,
+                  "src": "36227:13:1",
+                  "stateVariable": false,
+                  "storageLocation": "default",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_address",
+                    "typeString": "address"
+                  },
+                  "typeName": {
+                    "id": 1418,
+                    "name": "address",
+                    "nodeType": "ElementaryTypeName",
+                    "src": "36227:7:1",
+                    "stateMutability": "nonpayable",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_address",
+                      "typeString": "address"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                },
+                {
+                  "constant": false,
+                  "id": 1421,
+                  "name": "tokenId",
+                  "nodeType": "VariableDeclaration",
+                  "scope": 1447,
+                  "src": "36242:15:1",
+                  "stateVariable": false,
+                  "storageLocation": "default",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_uint256",
+                    "typeString": "uint256"
+                  },
+                  "typeName": {
+                    "id": 1420,
+                    "name": "uint256",
+                    "nodeType": "ElementaryTypeName",
+                    "src": "36242:7:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_uint256",
+                      "typeString": "uint256"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                }
+              ],
+              "src": "36226:32:1"
+            },
+            "returnParameters": {
+              "id": 1423,
+              "nodeType": "ParameterList",
+              "parameters": [],
+              "src": "36268:0:1"
+            },
+            "scope": 1448,
+            "src": "36212:240:1",
+            "stateMutability": "nonpayable",
+            "superFunction": 811,
+            "visibility": "internal"
+          }
+        ],
+        "scope": 1469,
+        "src": "33817:2637:1"
+      },
+      {
+        "id": 1449,
+        "literals": [
+          "solidity",
+          "^",
+          "0.5",
+          ".0"
+        ],
+        "nodeType": "PragmaDirective",
+        "src": "36518:23:1"
+      },
+      {
+        "baseContracts": [
+          {
+            "arguments": null,
+            "baseName": {
+              "contractScope": null,
+              "id": 1450,
+              "name": "ERC721",
+              "nodeType": "UserDefinedTypeName",
+              "referencedDeclaration": 944,
+              "src": "36838:6:1",
+              "typeDescriptions": {
+                "typeIdentifier": "t_contract$_ERC721_$944",
+                "typeString": "contract ERC721"
+              }
+            },
+            "id": 1451,
+            "nodeType": "InheritanceSpecifier",
+            "src": "36838:6:1"
+          },
+          {
+            "arguments": null,
+            "baseName": {
+              "contractScope": null,
+              "id": 1452,
+              "name": "ERC721Enumerable",
+              "nodeType": "UserDefinedTypeName",
+              "referencedDeclaration": 1302,
+              "src": "36846:16:1",
+              "typeDescriptions": {
+                "typeIdentifier": "t_contract$_ERC721Enumerable_$1302",
+                "typeString": "contract ERC721Enumerable"
+              }
+            },
+            "id": 1453,
+            "nodeType": "InheritanceSpecifier",
+            "src": "36846:16:1"
+          },
+          {
+            "arguments": null,
+            "baseName": {
+              "contractScope": null,
+              "id": 1454,
+              "name": "ERC721Metadata",
+              "nodeType": "UserDefinedTypeName",
+              "referencedDeclaration": 1448,
+              "src": "36864:14:1",
+              "typeDescriptions": {
+                "typeIdentifier": "t_contract$_ERC721Metadata_$1448",
+                "typeString": "contract ERC721Metadata"
+              }
+            },
+            "id": 1455,
+            "nodeType": "InheritanceSpecifier",
+            "src": "36864:14:1"
+          }
+        ],
+        "contractDependencies": [
+          944,
+          969,
+          23,
+          124,
+          386,
+          1302,
+          1323,
+          1448
+        ],
+        "contractKind": "contract",
+        "documentation": "@title Full ERC721 Token\nThis implementation includes all the required and some optional functionality of the ERC721 standard\nMoreover, it includes approve all functionality using operator terminology\n@dev see https://eips.ethereum.org/EIPS/eip-721",
+        "fullyImplemented": true,
+        "id": 1468,
+        "linearizedBaseContracts": [
+          1468,
+          1448,
+          1323,
+          1302,
+          969,
+          944,
+          124,
+          386,
+          23
+        ],
+        "name": "ERC721Full",
+        "nodeType": "ContractDefinition",
+        "nodes": [
+          {
+            "body": {
+              "id": 1466,
+              "nodeType": "Block",
+              "src": "36976:64:1",
+              "statements": []
+            },
+            "documentation": null,
+            "id": 1467,
+            "implemented": true,
+            "kind": "constructor",
+            "modifiers": [
+              {
+                "arguments": [
+                  {
+                    "argumentTypes": null,
+                    "id": 1462,
+                    "name": "name",
+                    "nodeType": "Identifier",
+                    "overloadedDeclarations": [],
+                    "referencedDeclaration": 1457,
+                    "src": "36962:4:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_string_memory_ptr",
+                      "typeString": "string memory"
+                    }
+                  },
+                  {
+                    "argumentTypes": null,
+                    "id": 1463,
+                    "name": "symbol",
+                    "nodeType": "Identifier",
+                    "overloadedDeclarations": [],
+                    "referencedDeclaration": 1459,
+                    "src": "36968:6:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_string_memory_ptr",
+                      "typeString": "string memory"
+                    }
+                  }
+                ],
+                "id": 1464,
+                "modifierName": {
+                  "argumentTypes": null,
+                  "id": 1461,
+                  "name": "ERC721Metadata",
+                  "nodeType": "Identifier",
+                  "overloadedDeclarations": [],
+                  "referencedDeclaration": 1448,
+                  "src": "36947:14:1",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_type$_t_contract$_ERC721Metadata_$1448_$",
+                    "typeString": "type(contract ERC721Metadata)"
+                  }
+                },
+                "nodeType": "ModifierInvocation",
+                "src": "36947:28:1"
+              }
+            ],
+            "name": "",
+            "nodeType": "FunctionDefinition",
+            "parameters": {
+              "id": 1460,
+              "nodeType": "ParameterList",
+              "parameters": [
+                {
+                  "constant": false,
+                  "id": 1457,
+                  "name": "name",
+                  "nodeType": "VariableDeclaration",
+                  "scope": 1467,
+                  "src": "36898:18:1",
+                  "stateVariable": false,
+                  "storageLocation": "memory",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_string_memory_ptr",
+                    "typeString": "string"
+                  },
+                  "typeName": {
+                    "id": 1456,
+                    "name": "string",
+                    "nodeType": "ElementaryTypeName",
+                    "src": "36898:6:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_string_storage_ptr",
+                      "typeString": "string"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                },
+                {
+                  "constant": false,
+                  "id": 1459,
+                  "name": "symbol",
+                  "nodeType": "VariableDeclaration",
+                  "scope": 1467,
+                  "src": "36918:20:1",
+                  "stateVariable": false,
+                  "storageLocation": "memory",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_string_memory_ptr",
+                    "typeString": "string"
+                  },
+                  "typeName": {
+                    "id": 1458,
+                    "name": "string",
+                    "nodeType": "ElementaryTypeName",
+                    "src": "36918:6:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_string_storage_ptr",
+                      "typeString": "string"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                }
+              ],
+              "src": "36897:42:1"
+            },
+            "returnParameters": {
+              "id": 1465,
+              "nodeType": "ParameterList",
+              "parameters": [],
+              "src": "36976:0:1"
+            },
+            "scope": 1468,
+            "src": "36885:155:1",
+            "stateMutability": "nonpayable",
+            "superFunction": null,
+            "visibility": "public"
+          }
+        ],
+        "scope": 1469,
+        "src": "36815:227:1"
+      }
+    ],
+    "src": "61:36982:1"
+  },
+  "compiler": {
+    "name": "solc",
+    "version": "0.5.0+commit.1d4f565a.Emscripten.clang"
+  },
+  "networks": {},
+  "schemaVersion": "3.0.2",
+  "updatedAt": "2019-09-05T15:01:09.096Z",
+  "devdoc": {
+    "details": "Interface for any contract that wants to support safeTransfers from ERC721 asset contracts.",
+    "methods": {
+      "onERC721Received(address,address,uint256,bytes)": {
+        "details": "The ERC721 smart contract calls this function on the recipient after a `safeTransfer`. This function MUST return the function selector, otherwise the caller will revert the transaction. The selector to be returned can be obtained as `this.onERC721Received.selector`. This function MAY throw to revert and reject the transfer. Note: the ERC721 contract address is always the message sender.",
+        "params": {
+          "data": "Additional data with no specified format",
+          "from": "The address which previously owned the token",
+          "operator": "The address which called `safeTransferFrom` function",
+          "tokenId": "The NFT identifier which is being transferred"
+        },
+        "return": "bytes4 `bytes4(keccak256(\"onERC721Received(address,address,uint256,bytes)\"))`"
+      }
+    },
+    "title": "ERC721 token receiver interface"
+  },
+  "userdoc": {
+    "methods": {
+      "onERC721Received(address,address,uint256,bytes)": {
+        "notice": "Handle the receipt of an NFT"
+      }
+    }
+  }
+}
\ No newline at end of file
diff --git a/src/abis/Migrations.json b/src/abis/Migrations.json
new file mode 100644
index 0000000..0e43b3c
--- /dev/null
+++ b/src/abis/Migrations.json
@@ -0,0 +1,1384 @@
+{
+  "contractName": "Migrations",
+  "abi": [
+    {
+      "constant": true,
+      "inputs": [],
+      "name": "last_completed_migration",
+      "outputs": [
+        {
+          "name": "",
+          "type": "uint256"
+        }
+      ],
+      "payable": false,
+      "stateMutability": "view",
+      "type": "function"
+    },
+    {
+      "constant": true,
+      "inputs": [],
+      "name": "owner",
+      "outputs": [
+        {
+          "name": "",
+          "type": "address"
+        }
+      ],
+      "payable": false,
+      "stateMutability": "view",
+      "type": "function"
+    },
+    {
+      "inputs": [],
+      "payable": false,
+      "stateMutability": "nonpayable",
+      "type": "constructor"
+    },
+    {
+      "constant": false,
+      "inputs": [
+        {
+          "name": "completed",
+          "type": "uint256"
+        }
+      ],
+      "name": "setCompleted",
+      "outputs": [],
+      "payable": false,
+      "stateMutability": "nonpayable",
+      "type": "function"
+    },
+    {
+      "constant": false,
+      "inputs": [
+        {
+          "name": "new_address",
+          "type": "address"
+        }
+      ],
+      "name": "upgrade",
+      "outputs": [],
+      "payable": false,
+      "stateMutability": "nonpayable",
+      "type": "function"
+    }
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+  }
+}
\ No newline at end of file
diff --git a/src/abis/SafeMath.json b/src/abis/SafeMath.json
new file mode 100644
index 0000000..40dd7a1
--- /dev/null
+++ b/src/abis/SafeMath.json
@@ -0,0 +1,37448 @@
+{
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+  "abi": [],
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+  "sourceMap": "4701:2939:1:-;;132:2:-1;166:7;155:9;146:7;137:37;252:7;246:14;243:1;238:23;232:4;229:33;270:1;265:20;;;;222:63;;265:20;274:9;222:63;;298:9;295:1;288:20;328:4;319:7;311:22;352:7;343;336:24",
+  "deployedSourceMap": "4701:2939:1:-;;;;;;;;",
+  "source": "\n// File: @openzeppelin/contracts/introspection/IERC165.sol\n\npragma solidity ^0.5.0;\n\n/**\n * @dev Interface of the ERC165 standard, as defined in the\n * [EIP](https://eips.ethereum.org/EIPS/eip-165).\n *\n * Implementers can declare support of contract interfaces, which can then be\n * queried by others (`ERC165Checker`).\n *\n * For an implementation, see `ERC165`.\n */\ninterface IERC165 {\n    /**\n     * @dev Returns true if this contract implements the interface defined by\n     * `interfaceId`. See the corresponding\n     * [EIP section](https://eips.ethereum.org/EIPS/eip-165#how-interfaces-are-identified)\n     * to learn more about how these ids are created.\n     *\n     * This function call must use less than 30 000 gas.\n     */\n    function supportsInterface(bytes4 interfaceId) external view returns (bool);\n}\n\n// File: @openzeppelin/contracts/token/ERC721/IERC721.sol\n\npragma solidity ^0.5.0;\n\n\n/**\n * @dev Required interface of an ERC721 compliant contract.\n */\ncontract IERC721 is IERC165 {\n    event Transfer(address indexed from, address indexed to, uint256 indexed tokenId);\n    event Approval(address indexed owner, address indexed approved, uint256 indexed tokenId);\n    event ApprovalForAll(address indexed owner, address indexed operator, bool approved);\n\n    /**\n     * @dev Returns the number of NFTs in `owner`'s account.\n     */\n    function balanceOf(address owner) public view returns (uint256 balance);\n\n    /**\n     * @dev Returns the owner of the NFT specified by `tokenId`.\n     */\n    function ownerOf(uint256 tokenId) public view returns (address owner);\n\n    /**\n     * @dev Transfers a specific NFT (`tokenId`) from one account (`from`) to\n     * another (`to`).\n     *\n     * \n     *\n     * Requirements:\n     * - `from`, `to` cannot be zero.\n     * - `tokenId` must be owned by `from`.\n     * - If the caller is not `from`, it must be have been allowed to move this\n     * NFT by either `approve` or `setApproveForAll`.\n     */\n    function safeTransferFrom(address from, address to, uint256 tokenId) public;\n    /**\n     * @dev Transfers a specific NFT (`tokenId`) from one account (`from`) to\n     * another (`to`).\n     *\n     * Requirements:\n     * - If the caller is not `from`, it must be approved to move this NFT by\n     * either `approve` or `setApproveForAll`.\n     */\n    function transferFrom(address from, address to, uint256 tokenId) public;\n    function approve(address to, uint256 tokenId) public;\n    function getApproved(uint256 tokenId) public view returns (address operator);\n\n    function setApprovalForAll(address operator, bool _approved) public;\n    function isApprovedForAll(address owner, address operator) public view returns (bool);\n\n\n    function safeTransferFrom(address from, address to, uint256 tokenId, bytes memory data) public;\n}\n\n// File: @openzeppelin/contracts/token/ERC721/IERC721Receiver.sol\n\npragma solidity ^0.5.0;\n\n/**\n * @title ERC721 token receiver interface\n * @dev Interface for any contract that wants to support safeTransfers\n * from ERC721 asset contracts.\n */\ncontract IERC721Receiver {\n    /**\n     * @notice Handle the receipt of an NFT\n     * @dev The ERC721 smart contract calls this function on the recipient\n     * after a `safeTransfer`. This function MUST return the function selector,\n     * otherwise the caller will revert the transaction. The selector to be\n     * returned can be obtained as `this.onERC721Received.selector`. This\n     * function MAY throw to revert and reject the transfer.\n     * Note: the ERC721 contract address is always the message sender.\n     * @param operator The address which called `safeTransferFrom` function\n     * @param from The address which previously owned the token\n     * @param tokenId The NFT identifier which is being transferred\n     * @param data Additional data with no specified format\n     * @return bytes4 `bytes4(keccak256(\"onERC721Received(address,address,uint256,bytes)\"))`\n     */\n    function onERC721Received(address operator, address from, uint256 tokenId, bytes memory data)\n    public returns (bytes4);\n}\n\n// File: @openzeppelin/contracts/math/SafeMath.sol\n\npragma solidity ^0.5.0;\n\n/**\n * @dev Wrappers over Solidity's arithmetic operations with added overflow\n * checks.\n *\n * Arithmetic operations in Solidity wrap on overflow. This can easily result\n * in bugs, because programmers usually assume that an overflow raises an\n * error, which is the standard behavior in high level programming languages.\n * `SafeMath` restores this intuition by reverting the transaction when an\n * operation overflows.\n *\n * Using this library instead of the unchecked operations eliminates an entire\n * class of bugs, so it's recommended to use it always.\n */\nlibrary SafeMath {\n    /**\n     * @dev Returns the addition of two unsigned integers, reverting on\n     * overflow.\n     *\n     * Counterpart to Solidity's `+` operator.\n     *\n     * Requirements:\n     * - Addition cannot overflow.\n     */\n    function add(uint256 a, uint256 b) internal pure returns (uint256) {\n        uint256 c = a + b;\n        require(c >= a, \"SafeMath: addition overflow\");\n\n        return c;\n    }\n\n    /**\n     * @dev Returns the subtraction of two unsigned integers, reverting on\n     * overflow (when the result is negative).\n     *\n     * Counterpart to Solidity's `-` operator.\n     *\n     * Requirements:\n     * - Subtraction cannot overflow.\n     */\n    function sub(uint256 a, uint256 b) internal pure returns (uint256) {\n        require(b <= a, \"SafeMath: subtraction overflow\");\n        uint256 c = a - b;\n\n        return c;\n    }\n\n    /**\n     * @dev Returns the multiplication of two unsigned integers, reverting on\n     * overflow.\n     *\n     * Counterpart to Solidity's `*` operator.\n     *\n     * Requirements:\n     * - Multiplication cannot overflow.\n     */\n    function mul(uint256 a, uint256 b) internal pure returns (uint256) {\n        // Gas optimization: this is cheaper than requiring 'a' not being zero, but the\n        // benefit is lost if 'b' is also tested.\n        // See: https://github.com/OpenZeppelin/openzeppelin-contracts/pull/522\n        if (a == 0) {\n            return 0;\n        }\n\n        uint256 c = a * b;\n        require(c / a == b, \"SafeMath: multiplication overflow\");\n\n        return c;\n    }\n\n    /**\n     * @dev Returns the integer division of two unsigned integers. Reverts on\n     * division by zero. The result is rounded towards zero.\n     *\n     * Counterpart to Solidity's `/` operator. Note: this function uses a\n     * `revert` opcode (which leaves remaining gas untouched) while Solidity\n     * uses an invalid opcode to revert (consuming all remaining gas).\n     *\n     * Requirements:\n     * - The divisor cannot be zero.\n     */\n    function div(uint256 a, uint256 b) internal pure returns (uint256) {\n        // Solidity only automatically asserts when dividing by 0\n        require(b > 0, \"SafeMath: division by zero\");\n        uint256 c = a / b;\n        // assert(a == b * c + a % b); // There is no case in which this doesn't hold\n\n        return c;\n    }\n\n    /**\n     * @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo),\n     * Reverts when dividing by zero.\n     *\n     * Counterpart to Solidity's `%` operator. This function uses a `revert`\n     * opcode (which leaves remaining gas untouched) while Solidity uses an\n     * invalid opcode to revert (consuming all remaining gas).\n     *\n     * Requirements:\n     * - The divisor cannot be zero.\n     */\n    function mod(uint256 a, uint256 b) internal pure returns (uint256) {\n        require(b != 0, \"SafeMath: modulo by zero\");\n        return a % b;\n    }\n}\n\n// File: @openzeppelin/contracts/utils/Address.sol\n\npragma solidity ^0.5.0;\n\n/**\n * @dev Collection of functions related to the address type,\n */\nlibrary Address {\n    /**\n     * @dev Returns true if `account` is a contract.\n     *\n     * This test is non-exhaustive, and there may be false-negatives: during the\n     * execution of a contract's constructor, its address will be reported as\n     * not containing a contract.\n     *\n     * > It is unsafe to assume that an address for which this function returns\n     * false is an externally-owned account (EOA) and not a contract.\n     */\n    function isContract(address account) internal view returns (bool) {\n        // This method relies in extcodesize, which returns 0 for contracts in\n        // construction, since the code is only stored at the end of the\n        // constructor execution.\n\n        uint256 size;\n        // solhint-disable-next-line no-inline-assembly\n        assembly { size := extcodesize(account) }\n        return size > 0;\n    }\n}\n\n// File: @openzeppelin/contracts/drafts/Counters.sol\n\npragma solidity ^0.5.0;\n\n\n/**\n * @title Counters\n * @author Matt Condon (@shrugs)\n * @dev Provides counters that can only be incremented or decremented by one. This can be used e.g. to track the number\n * of elements in a mapping, issuing ERC721 ids, or counting request ids.\n *\n * Include with `using Counters for Counters.Counter;`\n * Since it is not possible to overflow a 256 bit integer with increments of one, `increment` can skip the SafeMath\n * overflow check, thereby saving gas. This does assume however correct usage, in that the underlying `_value` is never\n * directly accessed.\n */\nlibrary Counters {\n    using SafeMath for uint256;\n\n    struct Counter {\n        // This variable should never be directly accessed by users of the library: interactions must be restricted to\n        // the library's function. As of Solidity v0.5.2, this cannot be enforced, though there is a proposal to add\n        // this feature: see https://github.com/ethereum/solidity/issues/4637\n        uint256 _value; // default: 0\n    }\n\n    function current(Counter storage counter) internal view returns (uint256) {\n        return counter._value;\n    }\n\n    function increment(Counter storage counter) internal {\n        counter._value += 1;\n    }\n\n    function decrement(Counter storage counter) internal {\n        counter._value = counter._value.sub(1);\n    }\n}\n\n// File: @openzeppelin/contracts/introspection/ERC165.sol\n\npragma solidity ^0.5.0;\n\n\n/**\n * @dev Implementation of the `IERC165` interface.\n *\n * Contracts may inherit from this and call `_registerInterface` to declare\n * their support of an interface.\n */\ncontract ERC165 is IERC165 {\n    /*\n     * bytes4(keccak256('supportsInterface(bytes4)')) == 0x01ffc9a7\n     */\n    bytes4 private constant _INTERFACE_ID_ERC165 = 0x01ffc9a7;\n\n    /**\n     * @dev Mapping of interface ids to whether or not it's supported.\n     */\n    mapping(bytes4 => bool) private _supportedInterfaces;\n\n    constructor () internal {\n        // Derived contracts need only register support for their own interfaces,\n        // we register support for ERC165 itself here\n        _registerInterface(_INTERFACE_ID_ERC165);\n    }\n\n    /**\n     * @dev See `IERC165.supportsInterface`.\n     *\n     * Time complexity O(1), guaranteed to always use less than 30 000 gas.\n     */\n    function supportsInterface(bytes4 interfaceId) external view returns (bool) {\n        return _supportedInterfaces[interfaceId];\n    }\n\n    /**\n     * @dev Registers the contract as an implementer of the interface defined by\n     * `interfaceId`. Support of the actual ERC165 interface is automatic and\n     * registering its interface id is not required.\n     *\n     * See `IERC165.supportsInterface`.\n     *\n     * Requirements:\n     *\n     * - `interfaceId` cannot be the ERC165 invalid interface (`0xffffffff`).\n     */\n    function _registerInterface(bytes4 interfaceId) internal {\n        require(interfaceId != 0xffffffff, \"ERC165: invalid interface id\");\n        _supportedInterfaces[interfaceId] = true;\n    }\n}\n\n// File: @openzeppelin/contracts/token/ERC721/ERC721.sol\n\npragma solidity ^0.5.0;\n\n\n\n\n\n\n\n/**\n * @title ERC721 Non-Fungible Token Standard basic implementation\n * @dev see https://eips.ethereum.org/EIPS/eip-721\n */\ncontract ERC721 is ERC165, IERC721 {\n    using SafeMath for uint256;\n    using Address for address;\n    using Counters for Counters.Counter;\n\n    // Equals to `bytes4(keccak256(\"onERC721Received(address,address,uint256,bytes)\"))`\n    // which can be also obtained as `IERC721Receiver(0).onERC721Received.selector`\n    bytes4 private constant _ERC721_RECEIVED = 0x150b7a02;\n\n    // Mapping from token ID to owner\n    mapping (uint256 => address) private _tokenOwner;\n\n    // Mapping from token ID to approved address\n    mapping (uint256 => address) private _tokenApprovals;\n\n    // Mapping from owner to number of owned token\n    mapping (address => Counters.Counter) private _ownedTokensCount;\n\n    // Mapping from owner to operator approvals\n    mapping (address => mapping (address => bool)) private _operatorApprovals;\n\n    /*\n     *     bytes4(keccak256('balanceOf(address)')) == 0x70a08231\n     *     bytes4(keccak256('ownerOf(uint256)')) == 0x6352211e\n     *     bytes4(keccak256('approve(address,uint256)')) == 0x095ea7b3\n     *     bytes4(keccak256('getApproved(uint256)')) == 0x081812fc\n     *     bytes4(keccak256('setApprovalForAll(address,bool)')) == 0xa22cb465\n     *     bytes4(keccak256('isApprovedForAll(address,address)')) == 0xe985e9c\n     *     bytes4(keccak256('transferFrom(address,address,uint256)')) == 0x23b872dd\n     *     bytes4(keccak256('safeTransferFrom(address,address,uint256)')) == 0x42842e0e\n     *     bytes4(keccak256('safeTransferFrom(address,address,uint256,bytes)')) == 0xb88d4fde\n     *\n     *     => 0x70a08231 ^ 0x6352211e ^ 0x095ea7b3 ^ 0x081812fc ^\n     *        0xa22cb465 ^ 0xe985e9c ^ 0x23b872dd ^ 0x42842e0e ^ 0xb88d4fde == 0x80ac58cd\n     */\n    bytes4 private constant _INTERFACE_ID_ERC721 = 0x80ac58cd;\n\n    constructor () public {\n        // register the supported interfaces to conform to ERC721 via ERC165\n        _registerInterface(_INTERFACE_ID_ERC721);\n    }\n\n    /**\n     * @dev Gets the balance of the specified address.\n     * @param owner address to query the balance of\n     * @return uint256 representing the amount owned by the passed address\n     */\n    function balanceOf(address owner) public view returns (uint256) {\n        require(owner != address(0), \"ERC721: balance query for the zero address\");\n\n        return _ownedTokensCount[owner].current();\n    }\n\n    /**\n     * @dev Gets the owner of the specified token ID.\n     * @param tokenId uint256 ID of the token to query the owner of\n     * @return address currently marked as the owner of the given token ID\n     */\n    function ownerOf(uint256 tokenId) public view returns (address) {\n        address owner = _tokenOwner[tokenId];\n        require(owner != address(0), \"ERC721: owner query for nonexistent token\");\n\n        return owner;\n    }\n\n    /**\n     * @dev Approves another address to transfer the given token ID\n     * The zero address indicates there is no approved address.\n     * There can only be one approved address per token at a given time.\n     * Can only be called by the token owner or an approved operator.\n     * @param to address to be approved for the given token ID\n     * @param tokenId uint256 ID of the token to be approved\n     */\n    function approve(address to, uint256 tokenId) public {\n        address owner = ownerOf(tokenId);\n        require(to != owner, \"ERC721: approval to current owner\");\n\n        require(msg.sender == owner || isApprovedForAll(owner, msg.sender),\n            \"ERC721: approve caller is not owner nor approved for all\"\n        );\n\n        _tokenApprovals[tokenId] = to;\n        emit Approval(owner, to, tokenId);\n    }\n\n    /**\n     * @dev Gets the approved address for a token ID, or zero if no address set\n     * Reverts if the token ID does not exist.\n     * @param tokenId uint256 ID of the token to query the approval of\n     * @return address currently approved for the given token ID\n     */\n    function getApproved(uint256 tokenId) public view returns (address) {\n        require(_exists(tokenId), \"ERC721: approved query for nonexistent token\");\n\n        return _tokenApprovals[tokenId];\n    }\n\n    /**\n     * @dev Sets or unsets the approval of a given operator\n     * An operator is allowed to transfer all tokens of the sender on their behalf.\n     * @param to operator address to set the approval\n     * @param approved representing the status of the approval to be set\n     */\n    function setApprovalForAll(address to, bool approved) public {\n        require(to != msg.sender, \"ERC721: approve to caller\");\n\n        _operatorApprovals[msg.sender][to] = approved;\n        emit ApprovalForAll(msg.sender, to, approved);\n    }\n\n    /**\n     * @dev Tells whether an operator is approved by a given owner.\n     * @param owner owner address which you want to query the approval of\n     * @param operator operator address which you want to query the approval of\n     * @return bool whether the given operator is approved by the given owner\n     */\n    function isApprovedForAll(address owner, address operator) public view returns (bool) {\n        return _operatorApprovals[owner][operator];\n    }\n\n    /**\n     * @dev Transfers the ownership of a given token ID to another address.\n     * Usage of this method is discouraged, use `safeTransferFrom` whenever possible.\n     * Requires the msg.sender to be the owner, approved, or operator.\n     * @param from current owner of the token\n     * @param to address to receive the ownership of the given token ID\n     * @param tokenId uint256 ID of the token to be transferred\n     */\n    function transferFrom(address from, address to, uint256 tokenId) public {\n        //solhint-disable-next-line max-line-length\n        require(_isApprovedOrOwner(msg.sender, tokenId), \"ERC721: transfer caller is not owner nor approved\");\n\n        _transferFrom(from, to, tokenId);\n    }\n\n    /**\n     * @dev Safely transfers the ownership of a given token ID to another address\n     * If the target address is a contract, it must implement `onERC721Received`,\n     * which is called upon a safe transfer, and return the magic value\n     * `bytes4(keccak256(\"onERC721Received(address,address,uint256,bytes)\"))`; otherwise,\n     * the transfer is reverted.\n     * Requires the msg.sender to be the owner, approved, or operator\n     * @param from current owner of the token\n     * @param to address to receive the ownership of the given token ID\n     * @param tokenId uint256 ID of the token to be transferred\n     */\n    function safeTransferFrom(address from, address to, uint256 tokenId) public {\n        safeTransferFrom(from, to, tokenId, \"\");\n    }\n\n    /**\n     * @dev Safely transfers the ownership of a given token ID to another address\n     * If the target address is a contract, it must implement `onERC721Received`,\n     * which is called upon a safe transfer, and return the magic value\n     * `bytes4(keccak256(\"onERC721Received(address,address,uint256,bytes)\"))`; otherwise,\n     * the transfer is reverted.\n     * Requires the msg.sender to be the owner, approved, or operator\n     * @param from current owner of the token\n     * @param to address to receive the ownership of the given token ID\n     * @param tokenId uint256 ID of the token to be transferred\n     * @param _data bytes data to send along with a safe transfer check\n     */\n    function safeTransferFrom(address from, address to, uint256 tokenId, bytes memory _data) public {\n        transferFrom(from, to, tokenId);\n        require(_checkOnERC721Received(from, to, tokenId, _data), \"ERC721: transfer to non ERC721Receiver implementer\");\n    }\n\n    /**\n     * @dev Returns whether the specified token exists.\n     * @param tokenId uint256 ID of the token to query the existence of\n     * @return bool whether the token exists\n     */\n    function _exists(uint256 tokenId) internal view returns (bool) {\n        address owner = _tokenOwner[tokenId];\n        return owner != address(0);\n    }\n\n    /**\n     * @dev Returns whether the given spender can transfer a given token ID.\n     * @param spender address of the spender to query\n     * @param tokenId uint256 ID of the token to be transferred\n     * @return bool whether the msg.sender is approved for the given token ID,\n     * is an operator of the owner, or is the owner of the token\n     */\n    function _isApprovedOrOwner(address spender, uint256 tokenId) internal view returns (bool) {\n        require(_exists(tokenId), \"ERC721: operator query for nonexistent token\");\n        address owner = ownerOf(tokenId);\n        return (spender == owner || getApproved(tokenId) == spender || isApprovedForAll(owner, spender));\n    }\n\n    /**\n     * @dev Internal function to mint a new token.\n     * Reverts if the given token ID already exists.\n     * @param to The address that will own the minted token\n     * @param tokenId uint256 ID of the token to be minted\n     */\n    function _mint(address to, uint256 tokenId) internal {\n        require(to != address(0), \"ERC721: mint to the zero address\");\n        require(!_exists(tokenId), \"ERC721: token already minted\");\n\n        _tokenOwner[tokenId] = to;\n        _ownedTokensCount[to].increment();\n\n        emit Transfer(address(0), to, tokenId);\n    }\n\n    /**\n     * @dev Internal function to burn a specific token.\n     * Reverts if the token does not exist.\n     * Deprecated, use _burn(uint256) instead.\n     * @param owner owner of the token to burn\n     * @param tokenId uint256 ID of the token being burned\n     */\n    function _burn(address owner, uint256 tokenId) internal {\n        require(ownerOf(tokenId) == owner, \"ERC721: burn of token that is not own\");\n\n        _clearApproval(tokenId);\n\n        _ownedTokensCount[owner].decrement();\n        _tokenOwner[tokenId] = address(0);\n\n        emit Transfer(owner, address(0), tokenId);\n    }\n\n    /**\n     * @dev Internal function to burn a specific token.\n     * Reverts if the token does not exist.\n     * @param tokenId uint256 ID of the token being burned\n     */\n    function _burn(uint256 tokenId) internal {\n        _burn(ownerOf(tokenId), tokenId);\n    }\n\n    /**\n     * @dev Internal function to transfer ownership of a given token ID to another address.\n     * As opposed to transferFrom, this imposes no restrictions on msg.sender.\n     * @param from current owner of the token\n     * @param to address to receive the ownership of the given token ID\n     * @param tokenId uint256 ID of the token to be transferred\n     */\n    function _transferFrom(address from, address to, uint256 tokenId) internal {\n        require(ownerOf(tokenId) == from, \"ERC721: transfer of token that is not own\");\n        require(to != address(0), \"ERC721: transfer to the zero address\");\n\n        _clearApproval(tokenId);\n\n        _ownedTokensCount[from].decrement();\n        _ownedTokensCount[to].increment();\n\n        _tokenOwner[tokenId] = to;\n\n        emit Transfer(from, to, tokenId);\n    }\n\n    /**\n     * @dev Internal function to invoke `onERC721Received` on a target address.\n     * The call is not executed if the target address is not a contract.\n     *\n     * This function is deprecated.\n     * @param from address representing the previous owner of the given token ID\n     * @param to target address that will receive the tokens\n     * @param tokenId uint256 ID of the token to be transferred\n     * @param _data bytes optional data to send along with the call\n     * @return bool whether the call correctly returned the expected magic value\n     */\n    function _checkOnERC721Received(address from, address to, uint256 tokenId, bytes memory _data)\n        internal returns (bool)\n    {\n        if (!to.isContract()) {\n            return true;\n        }\n\n        bytes4 retval = IERC721Receiver(to).onERC721Received(msg.sender, from, tokenId, _data);\n        return (retval == _ERC721_RECEIVED);\n    }\n\n    /**\n     * @dev Private function to clear current approval of a given token ID.\n     * @param tokenId uint256 ID of the token to be transferred\n     */\n    function _clearApproval(uint256 tokenId) private {\n        if (_tokenApprovals[tokenId] != address(0)) {\n            _tokenApprovals[tokenId] = address(0);\n        }\n    }\n}\n\n// File: @openzeppelin/contracts/token/ERC721/IERC721Enumerable.sol\n\npragma solidity ^0.5.0;\n\n\n/**\n * @title ERC-721 Non-Fungible Token Standard, optional enumeration extension\n * @dev See https://eips.ethereum.org/EIPS/eip-721\n */\ncontract IERC721Enumerable is IERC721 {\n    function totalSupply() public view returns (uint256);\n    function tokenOfOwnerByIndex(address owner, uint256 index) public view returns (uint256 tokenId);\n\n    function tokenByIndex(uint256 index) public view returns (uint256);\n}\n\n// File: @openzeppelin/contracts/token/ERC721/ERC721Enumerable.sol\n\npragma solidity ^0.5.0;\n\n\n\n\n/**\n * @title ERC-721 Non-Fungible Token with optional enumeration extension logic\n * @dev See https://eips.ethereum.org/EIPS/eip-721\n */\ncontract ERC721Enumerable is ERC165, ERC721, IERC721Enumerable {\n    // Mapping from owner to list of owned token IDs\n    mapping(address => uint256[]) private _ownedTokens;\n\n    // Mapping from token ID to index of the owner tokens list\n    mapping(uint256 => uint256) private _ownedTokensIndex;\n\n    // Array with all token ids, used for enumeration\n    uint256[] private _allTokens;\n\n    // Mapping from token id to position in the allTokens array\n    mapping(uint256 => uint256) private _allTokensIndex;\n\n    /*\n     *     bytes4(keccak256('totalSupply()')) == 0x18160ddd\n     *     bytes4(keccak256('tokenOfOwnerByIndex(address,uint256)')) == 0x2f745c59\n     *     bytes4(keccak256('tokenByIndex(uint256)')) == 0x4f6ccce7\n     *\n     *     => 0x18160ddd ^ 0x2f745c59 ^ 0x4f6ccce7 == 0x780e9d63\n     */\n    bytes4 private constant _INTERFACE_ID_ERC721_ENUMERABLE = 0x780e9d63;\n\n    /**\n     * @dev Constructor function.\n     */\n    constructor () public {\n        // register the supported interface to conform to ERC721Enumerable via ERC165\n        _registerInterface(_INTERFACE_ID_ERC721_ENUMERABLE);\n    }\n\n    /**\n     * @dev Gets the token ID at a given index of the tokens list of the requested owner.\n     * @param owner address owning the tokens list to be accessed\n     * @param index uint256 representing the index to be accessed of the requested tokens list\n     * @return uint256 token ID at the given index of the tokens list owned by the requested address\n     */\n    function tokenOfOwnerByIndex(address owner, uint256 index) public view returns (uint256) {\n        require(index < balanceOf(owner), \"ERC721Enumerable: owner index out of bounds\");\n        return _ownedTokens[owner][index];\n    }\n\n    /**\n     * @dev Gets the total amount of tokens stored by the contract.\n     * @return uint256 representing the total amount of tokens\n     */\n    function totalSupply() public view returns (uint256) {\n        return _allTokens.length;\n    }\n\n    /**\n     * @dev Gets the token ID at a given index of all the tokens in this contract\n     * Reverts if the index is greater or equal to the total number of tokens.\n     * @param index uint256 representing the index to be accessed of the tokens list\n     * @return uint256 token ID at the given index of the tokens list\n     */\n    function tokenByIndex(uint256 index) public view returns (uint256) {\n        require(index < totalSupply(), \"ERC721Enumerable: global index out of bounds\");\n        return _allTokens[index];\n    }\n\n    /**\n     * @dev Internal function to transfer ownership of a given token ID to another address.\n     * As opposed to transferFrom, this imposes no restrictions on msg.sender.\n     * @param from current owner of the token\n     * @param to address to receive the ownership of the given token ID\n     * @param tokenId uint256 ID of the token to be transferred\n     */\n    function _transferFrom(address from, address to, uint256 tokenId) internal {\n        super._transferFrom(from, to, tokenId);\n\n        _removeTokenFromOwnerEnumeration(from, tokenId);\n\n        _addTokenToOwnerEnumeration(to, tokenId);\n    }\n\n    /**\n     * @dev Internal function to mint a new token.\n     * Reverts if the given token ID already exists.\n     * @param to address the beneficiary that will own the minted token\n     * @param tokenId uint256 ID of the token to be minted\n     */\n    function _mint(address to, uint256 tokenId) internal {\n        super._mint(to, tokenId);\n\n        _addTokenToOwnerEnumeration(to, tokenId);\n\n        _addTokenToAllTokensEnumeration(tokenId);\n    }\n\n    /**\n     * @dev Internal function to burn a specific token.\n     * Reverts if the token does not exist.\n     * Deprecated, use _burn(uint256) instead.\n     * @param owner owner of the token to burn\n     * @param tokenId uint256 ID of the token being burned\n     */\n    function _burn(address owner, uint256 tokenId) internal {\n        super._burn(owner, tokenId);\n\n        _removeTokenFromOwnerEnumeration(owner, tokenId);\n        // Since tokenId will be deleted, we can clear its slot in _ownedTokensIndex to trigger a gas refund\n        _ownedTokensIndex[tokenId] = 0;\n\n        _removeTokenFromAllTokensEnumeration(tokenId);\n    }\n\n    /**\n     * @dev Gets the list of token IDs of the requested owner.\n     * @param owner address owning the tokens\n     * @return uint256[] List of token IDs owned by the requested address\n     */\n    function _tokensOfOwner(address owner) internal view returns (uint256[] storage) {\n        return _ownedTokens[owner];\n    }\n\n    /**\n     * @dev Private function to add a token to this extension's ownership-tracking data structures.\n     * @param to address representing the new owner of the given token ID\n     * @param tokenId uint256 ID of the token to be added to the tokens list of the given address\n     */\n    function _addTokenToOwnerEnumeration(address to, uint256 tokenId) private {\n        _ownedTokensIndex[tokenId] = _ownedTokens[to].length;\n        _ownedTokens[to].push(tokenId);\n    }\n\n    /**\n     * @dev Private function to add a token to this extension's token tracking data structures.\n     * @param tokenId uint256 ID of the token to be added to the tokens list\n     */\n    function _addTokenToAllTokensEnumeration(uint256 tokenId) private {\n        _allTokensIndex[tokenId] = _allTokens.length;\n        _allTokens.push(tokenId);\n    }\n\n    /**\n     * @dev Private function to remove a token from this extension's ownership-tracking data structures. Note that\n     * while the token is not assigned a new owner, the _ownedTokensIndex mapping is _not_ updated: this allows for\n     * gas optimizations e.g. when performing a transfer operation (avoiding double writes).\n     * This has O(1) time complexity, but alters the order of the _ownedTokens array.\n     * @param from address representing the previous owner of the given token ID\n     * @param tokenId uint256 ID of the token to be removed from the tokens list of the given address\n     */\n    function _removeTokenFromOwnerEnumeration(address from, uint256 tokenId) private {\n        // To prevent a gap in from's tokens array, we store the last token in the index of the token to delete, and\n        // then delete the last slot (swap and pop).\n\n        uint256 lastTokenIndex = _ownedTokens[from].length.sub(1);\n        uint256 tokenIndex = _ownedTokensIndex[tokenId];\n\n        // When the token to delete is the last token, the swap operation is unnecessary\n        if (tokenIndex != lastTokenIndex) {\n            uint256 lastTokenId = _ownedTokens[from][lastTokenIndex];\n\n            _ownedTokens[from][tokenIndex] = lastTokenId; // Move the last token to the slot of the to-delete token\n            _ownedTokensIndex[lastTokenId] = tokenIndex; // Update the moved token's index\n        }\n\n        // This also deletes the contents at the last position of the array\n        _ownedTokens[from].length--;\n\n        // Note that _ownedTokensIndex[tokenId] hasn't been cleared: it still points to the old slot (now occupied by\n        // lastTokenId, or just over the end of the array if the token was the last one).\n    }\n\n    /**\n     * @dev Private function to remove a token from this extension's token tracking data structures.\n     * This has O(1) time complexity, but alters the order of the _allTokens array.\n     * @param tokenId uint256 ID of the token to be removed from the tokens list\n     */\n    function _removeTokenFromAllTokensEnumeration(uint256 tokenId) private {\n        // To prevent a gap in the tokens array, we store the last token in the index of the token to delete, and\n        // then delete the last slot (swap and pop).\n\n        uint256 lastTokenIndex = _allTokens.length.sub(1);\n        uint256 tokenIndex = _allTokensIndex[tokenId];\n\n        // When the token to delete is the last token, the swap operation is unnecessary. However, since this occurs so\n        // rarely (when the last minted token is burnt) that we still do the swap here to avoid the gas cost of adding\n        // an 'if' statement (like in _removeTokenFromOwnerEnumeration)\n        uint256 lastTokenId = _allTokens[lastTokenIndex];\n\n        _allTokens[tokenIndex] = lastTokenId; // Move the last token to the slot of the to-delete token\n        _allTokensIndex[lastTokenId] = tokenIndex; // Update the moved token's index\n\n        // This also deletes the contents at the last position of the array\n        _allTokens.length--;\n        _allTokensIndex[tokenId] = 0;\n    }\n}\n\n// File: @openzeppelin/contracts/token/ERC721/IERC721Metadata.sol\n\npragma solidity ^0.5.0;\n\n\n/**\n * @title ERC-721 Non-Fungible Token Standard, optional metadata extension\n * @dev See https://eips.ethereum.org/EIPS/eip-721\n */\ncontract IERC721Metadata is IERC721 {\n    function name() external view returns (string memory);\n    function symbol() external view returns (string memory);\n    function tokenURI(uint256 tokenId) external view returns (string memory);\n}\n\n// File: @openzeppelin/contracts/token/ERC721/ERC721Metadata.sol\n\npragma solidity ^0.5.0;\n\n\n\n\ncontract ERC721Metadata is ERC165, ERC721, IERC721Metadata {\n    // Token name\n    string private _name;\n\n    // Token symbol\n    string private _symbol;\n\n    // Optional mapping for token URIs\n    mapping(uint256 => string) private _tokenURIs;\n\n    /*\n     *     bytes4(keccak256('name()')) == 0x06fdde03\n     *     bytes4(keccak256('symbol()')) == 0x95d89b41\n     *     bytes4(keccak256('tokenURI(uint256)')) == 0xc87b56dd\n     *\n     *     => 0x06fdde03 ^ 0x95d89b41 ^ 0xc87b56dd == 0x5b5e139f\n     */\n    bytes4 private constant _INTERFACE_ID_ERC721_METADATA = 0x5b5e139f;\n\n    /**\n     * @dev Constructor function\n     */\n    constructor (string memory name, string memory symbol) public {\n        _name = name;\n        _symbol = symbol;\n\n        // register the supported interfaces to conform to ERC721 via ERC165\n        _registerInterface(_INTERFACE_ID_ERC721_METADATA);\n    }\n\n    /**\n     * @dev Gets the token name.\n     * @return string representing the token name\n     */\n    function name() external view returns (string memory) {\n        return _name;\n    }\n\n    /**\n     * @dev Gets the token symbol.\n     * @return string representing the token symbol\n     */\n    function symbol() external view returns (string memory) {\n        return _symbol;\n    }\n\n    /**\n     * @dev Returns an URI for a given token ID.\n     * Throws if the token ID does not exist. May return an empty string.\n     * @param tokenId uint256 ID of the token to query\n     */\n    function tokenURI(uint256 tokenId) external view returns (string memory) {\n        require(_exists(tokenId), \"ERC721Metadata: URI query for nonexistent token\");\n        return _tokenURIs[tokenId];\n    }\n\n    /**\n     * @dev Internal function to set the token URI for a given token.\n     * Reverts if the token ID does not exist.\n     * @param tokenId uint256 ID of the token to set its URI\n     * @param uri string URI to assign\n     */\n    function _setTokenURI(uint256 tokenId, string memory uri) internal {\n        require(_exists(tokenId), \"ERC721Metadata: URI set of nonexistent token\");\n        _tokenURIs[tokenId] = uri;\n    }\n\n    /**\n     * @dev Internal function to burn a specific token.\n     * Reverts if the token does not exist.\n     * Deprecated, use _burn(uint256) instead.\n     * @param owner owner of the token to burn\n     * @param tokenId uint256 ID of the token being burned by the msg.sender\n     */\n    function _burn(address owner, uint256 tokenId) internal {\n        super._burn(owner, tokenId);\n\n        // Clear metadata (if any)\n        if (bytes(_tokenURIs[tokenId]).length != 0) {\n            delete _tokenURIs[tokenId];\n        }\n    }\n}\n\n// File: @openzeppelin/contracts/token/ERC721/ERC721Full.sol\n\npragma solidity ^0.5.0;\n\n\n\n\n/**\n * @title Full ERC721 Token\n * This implementation includes all the required and some optional functionality of the ERC721 standard\n * Moreover, it includes approve all functionality using operator terminology\n * @dev see https://eips.ethereum.org/EIPS/eip-721\n */\ncontract ERC721Full is ERC721, ERC721Enumerable, ERC721Metadata {\n    constructor (string memory name, string memory symbol) public ERC721Metadata(name, symbol) {\n        // solhint-disable-previous-line no-empty-blocks\n    }\n}\n",
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+                          "typeIdentifier": "t_mapping$_t_uint256_$_t_address_$",
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+                          "typeString": "uint256"
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+                        "typeString": "address"
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+                        "name": "from",
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+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        }
+                      },
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+                        "name": "to",
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+                        "typeDescriptions": {
+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        }
+                      },
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+                        "src": "22780:7:1",
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+                          "typeString": "uint256"
+                        }
+                      }
+                    ],
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+                      "argumentTypes": [
+                        {
+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        },
+                        {
+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        },
+                        {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      ],
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+                      "name": "Transfer",
+                      "nodeType": "Identifier",
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+                      }
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+                  "nodeType": "EmitStatement",
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+                }
+              ]
+            },
+            "documentation": "@dev Internal function to transfer ownership of a given token ID to another address.\nAs opposed to transferFrom, this imposes no restrictions on msg.sender.\n@param from current owner of the token\n@param to address to receive the ownership of the given token ID\n@param tokenId uint256 ID of the token to be transferred",
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+                    "typeString": "address"
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+                      "typeIdentifier": "t_address",
+                      "typeString": "address"
+                    }
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+                    "typeString": "address"
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+                    "name": "address",
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+                      "typeString": "address"
+                    }
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+            "visibility": "internal"
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+                          "name": "to",
+                          "nodeType": "Identifier",
+                          "overloadedDeclarations": [],
+                          "referencedDeclaration": 884,
+                          "src": "23514:2:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_address",
+                            "typeString": "address"
+                          }
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+                        "src": "23514:13:1",
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+                        "name": "bytes4",
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+                          "typeIdentifier": "t_bytes4",
+                          "typeString": "bytes4"
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+                        "expression": {
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+                          "id": 907,
+                          "name": "msg",
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+                          "src": "23630:3:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_magic_message",
+                            "typeString": "msg"
+                          }
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+                        "isLValue": false,
+                        "isPure": false,
+                        "lValueRequested": false,
+                        "memberName": "sender",
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+                        "src": "23630:10:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_address_payable",
+                          "typeString": "address payable"
+                        }
+                      },
+                      {
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+                        "id": 909,
+                        "name": "from",
+                        "nodeType": "Identifier",
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+                        "src": "23642:4:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        }
+                      },
+                      {
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+                        "id": 910,
+                        "name": "tokenId",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
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+                        "src": "23648:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      },
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+                        "id": 911,
+                        "name": "_data",
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+                        "src": "23657:5:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_bytes_memory_ptr",
+                          "typeString": "bytes memory"
+                        }
+                      }
+                    ],
+                    "expression": {
+                      "argumentTypes": [
+                        {
+                          "typeIdentifier": "t_address_payable",
+                          "typeString": "address payable"
+                        },
+                        {
+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        },
+                        {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        },
+                        {
+                          "typeIdentifier": "t_bytes_memory_ptr",
+                          "typeString": "bytes memory"
+                        }
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+                        "arguments": [
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+                            "id": 904,
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+                            "src": "23609:2:1",
+                            "typeDescriptions": {
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+                              "typeString": "address"
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+                              "typeIdentifier": "t_address",
+                              "typeString": "address"
+                            }
+                          ],
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+                          "name": "IERC721Receiver",
+                          "nodeType": "Identifier",
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+                          "referencedDeclaration": 139,
+                          "src": "23593:15:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_type$_t_contract$_IERC721Receiver_$139_$",
+                            "typeString": "type(contract IERC721Receiver)"
+                          }
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+                        "isLValue": false,
+                        "isPure": false,
+                        "kind": "typeConversion",
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+                        "typeDescriptions": {
+                          "typeIdentifier": "t_contract$_IERC721Receiver_$139",
+                          "typeString": "contract IERC721Receiver"
+                        }
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+                      "memberName": "onERC721Received",
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+                      "src": "23593:36:1",
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+                        "typeString": "function (address,address,uint256,bytes memory) external returns (bytes4)"
+                      }
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+                      "typeString": "bytes4"
+                    }
+                  },
+                  "nodeType": "VariableDeclarationStatement",
+                  "src": "23577:86:1"
+                },
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+                    "components": [
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+                        "argumentTypes": null,
+                        "commonType": {
+                          "typeIdentifier": "t_bytes4",
+                          "typeString": "bytes4"
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+                        "lValueRequested": false,
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+                          "name": "retval",
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+                          "overloadedDeclarations": [],
+                          "referencedDeclaration": 902,
+                          "src": "23681:6:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_bytes4",
+                            "typeString": "bytes4"
+                          }
+                        },
+                        "nodeType": "BinaryOperation",
+                        "operator": "==",
+                        "rightExpression": {
+                          "argumentTypes": null,
+                          "id": 915,
+                          "name": "_ERC721_RECEIVED",
+                          "nodeType": "Identifier",
+                          "overloadedDeclarations": [],
+                          "referencedDeclaration": 403,
+                          "src": "23691:16:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_bytes4",
+                            "typeString": "bytes4"
+                          }
+                        },
+                        "src": "23681:26:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_bool",
+                          "typeString": "bool"
+                        }
+                      }
+                    ],
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+                    "isConstant": false,
+                    "isInlineArray": false,
+                    "isLValue": false,
+                    "isPure": false,
+                    "lValueRequested": false,
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+                    "src": "23680:28:1",
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+                  },
+                  "functionReturnParameters": 892,
+                  "id": 918,
+                  "nodeType": "Return",
+                  "src": "23673:35:1"
+                }
+              ]
+            },
+            "documentation": "@dev Internal function to invoke `onERC721Received` on a target address.\nThe call is not executed if the target address is not a contract.\n     * This function is deprecated.\n@param from address representing the previous owner of the given token ID\n@param to target address that will receive the tokens\n@param tokenId uint256 ID of the token to be transferred\n@param _data bytes optional data to send along with the call\n@return bool whether the call correctly returned the expected magic value",
+            "id": 920,
+            "implemented": true,
+            "kind": "function",
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+            "name": "_checkOnERC721Received",
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+                  "scope": 920,
+                  "src": "23400:12:1",
+                  "stateVariable": false,
+                  "storageLocation": "default",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_address",
+                    "typeString": "address"
+                  },
+                  "typeName": {
+                    "id": 881,
+                    "name": "address",
+                    "nodeType": "ElementaryTypeName",
+                    "src": "23400:7:1",
+                    "stateMutability": "nonpayable",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_address",
+                      "typeString": "address"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                },
+                {
+                  "constant": false,
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+                      "src": "27266:10:1",
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+                        "src": "27780:7:1",
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+                          "typeString": "uint256"
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+                          "typeString": "address"
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+                          "typeString": "address"
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+                        {
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+                          "typeString": "uint256"
+                        }
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+                      "typeString": "tuple()"
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+                        "nodeType": "Identifier",
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+                        "src": "28342:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
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+                        {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
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+                      "name": "_addTokenToAllTokensEnumeration",
+                      "nodeType": "Identifier",
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+                      "src": "28310:31:1",
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+                        "typeString": "function (uint256)"
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+                }
+              ]
+            },
+            "documentation": "@dev Internal function to mint a new token.\nReverts if the given token ID already exists.\n@param to address the beneficiary that will own the minted token\n@param tokenId uint256 ID of the token to be minted",
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+                  "stateVariable": false,
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+                    "typeString": "address"
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+                    "name": "address",
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+                      "typeIdentifier": "t_address",
+                      "typeString": "address"
+                    }
+                  },
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+                  "src": "28188:15:1",
+                  "stateVariable": false,
+                  "storageLocation": "default",
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+                    "typeString": "uint256"
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+                      "typeString": "uint256"
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+                  "visibility": "internal"
+                }
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+            "visibility": "internal"
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+                        "name": "owner",
+                        "nodeType": "Identifier",
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+                        "src": "28710:5:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        }
+                      },
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+                        "id": 1120,
+                        "name": "tokenId",
+                        "nodeType": "Identifier",
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+                        "referencedDeclaration": 1113,
+                        "src": "28717:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
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+                      "argumentTypes": [
+                        {
+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        },
+                        {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      ],
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+                        "id": 1116,
+                        "name": "super",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 1572,
+                        "src": "28698:5:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_super$_ERC721Enumerable_$1302",
+                          "typeString": "contract super ERC721Enumerable"
+                        }
+                      },
+                      "id": 1118,
+                      "isConstant": false,
+                      "isLValue": false,
+                      "isPure": false,
+                      "lValueRequested": false,
+                      "memberName": "_burn",
+                      "nodeType": "MemberAccess",
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+                      "src": "28698:11:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_function_internal_nonpayable$_t_address_$_t_uint256_$returns$__$",
+                        "typeString": "function (address,uint256)"
+                      }
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+                    "kind": "functionCall",
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+                    "nodeType": "FunctionCall",
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+                      "typeString": "tuple()"
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+                        "id": 1124,
+                        "name": "owner",
+                        "nodeType": "Identifier",
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+                        "src": "28769:5:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        }
+                      },
+                      {
+                        "argumentTypes": null,
+                        "id": 1125,
+                        "name": "tokenId",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 1113,
+                        "src": "28776:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      }
+                    ],
+                    "expression": {
+                      "argumentTypes": [
+                        {
+                          "typeIdentifier": "t_address",
+                          "typeString": "address"
+                        },
+                        {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      ],
+                      "id": 1123,
+                      "name": "_removeTokenFromOwnerEnumeration",
+                      "nodeType": "Identifier",
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+                      "referencedDeclaration": 1252,
+                      "src": "28736:32:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_function_internal_nonpayable$_t_address_$_t_uint256_$returns$__$",
+                        "typeString": "function (address,uint256)"
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+                    "isLValue": false,
+                    "isPure": false,
+                    "kind": "functionCall",
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+                    "nodeType": "FunctionCall",
+                    "src": "28736:48:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_tuple$__$",
+                      "typeString": "tuple()"
+                    }
+                  },
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+                  "nodeType": "ExpressionStatement",
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+                },
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+                      "baseExpression": {
+                        "argumentTypes": null,
+                        "id": 1128,
+                        "name": "_ownedTokensIndex",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 985,
+                        "src": "28903:17:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_mapping$_t_uint256_$_t_uint256_$",
+                          "typeString": "mapping(uint256 => uint256)"
+                        }
+                      },
+                      "id": 1130,
+                      "indexExpression": {
+                        "argumentTypes": null,
+                        "id": 1129,
+                        "name": "tokenId",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 1113,
+                        "src": "28921:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      },
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+                      "isLValue": true,
+                      "isPure": false,
+                      "lValueRequested": true,
+                      "nodeType": "IndexAccess",
+                      "src": "28903:26:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_uint256",
+                        "typeString": "uint256"
+                      }
+                    },
+                    "nodeType": "Assignment",
+                    "operator": "=",
+                    "rightHandSide": {
+                      "argumentTypes": null,
+                      "hexValue": "30",
+                      "id": 1131,
+                      "isConstant": false,
+                      "isLValue": false,
+                      "isPure": true,
+                      "kind": "number",
+                      "lValueRequested": false,
+                      "nodeType": "Literal",
+                      "src": "28932:1:1",
+                      "subdenomination": null,
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_rational_0_by_1",
+                        "typeString": "int_const 0"
+                      },
+                      "value": "0"
+                    },
+                    "src": "28903:30:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_uint256",
+                      "typeString": "uint256"
+                    }
+                  },
+                  "id": 1133,
+                  "nodeType": "ExpressionStatement",
+                  "src": "28903:30:1"
+                },
+                {
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+                    "arguments": [
+                      {
+                        "argumentTypes": null,
+                        "id": 1135,
+                        "name": "tokenId",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 1113,
+                        "src": "28981:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      }
+                    ],
+                    "expression": {
+                      "argumentTypes": [
+                        {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      ],
+                      "id": 1134,
+                      "name": "_removeTokenFromAllTokensEnumeration",
+                      "nodeType": "Identifier",
+                      "overloadedDeclarations": [],
+                      "referencedDeclaration": 1301,
+                      "src": "28944:36:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_function_internal_nonpayable$_t_uint256_$returns$__$",
+                        "typeString": "function (uint256)"
+                      }
+                    },
+                    "id": 1136,
+                    "isConstant": false,
+                    "isLValue": false,
+                    "isPure": false,
+                    "kind": "functionCall",
+                    "lValueRequested": false,
+                    "names": [],
+                    "nodeType": "FunctionCall",
+                    "src": "28944:45:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_tuple$__$",
+                      "typeString": "tuple()"
+                    }
+                  },
+                  "id": 1137,
+                  "nodeType": "ExpressionStatement",
+                  "src": "28944:45:1"
+                }
+              ]
+            },
+            "documentation": "@dev Internal function to burn a specific token.\nReverts if the token does not exist.\nDeprecated, use _burn(uint256) instead.\n@param owner owner of the token to burn\n@param tokenId uint256 ID of the token being burned",
+            "id": 1139,
+            "implemented": true,
+            "kind": "function",
+            "modifiers": [],
+            "name": "_burn",
+            "nodeType": "FunctionDefinition",
+            "parameters": {
+              "id": 1114,
+              "nodeType": "ParameterList",
+              "parameters": [
+                {
+                  "constant": false,
+                  "id": 1111,
+                  "name": "owner",
+                  "nodeType": "VariableDeclaration",
+                  "scope": 1139,
+                  "src": "28647:13:1",
+                  "stateVariable": false,
+                  "storageLocation": "default",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_address",
+                    "typeString": "address"
+                  },
+                  "typeName": {
+                    "id": 1110,
+                    "name": "address",
+                    "nodeType": "ElementaryTypeName",
+                    "src": "28647:7:1",
+                    "stateMutability": "nonpayable",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_address",
+                      "typeString": "address"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                },
+                {
+                  "constant": false,
+                  "id": 1113,
+                  "name": "tokenId",
+                  "nodeType": "VariableDeclaration",
+                  "scope": 1139,
+                  "src": "28662:15:1",
+                  "stateVariable": false,
+                  "storageLocation": "default",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_uint256",
+                    "typeString": "uint256"
+                  },
+                  "typeName": {
+                    "id": 1112,
+                    "name": "uint256",
+                    "nodeType": "ElementaryTypeName",
+                    "src": "28662:7:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_uint256",
+                      "typeString": "uint256"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                }
+              ],
+              "src": "28646:32:1"
+            },
+            "returnParameters": {
+              "id": 1115,
+              "nodeType": "ParameterList",
+              "parameters": [],
+              "src": "28688:0:1"
+            },
+            "scope": 1302,
+            "src": "28632:364:1",
+            "stateMutability": "nonpayable",
+            "superFunction": 811,
+            "visibility": "internal"
+          },
+          {
+            "body": {
+              "id": 1151,
+              "nodeType": "Block",
+              "src": "29282:43:1",
+              "statements": [
+                {
+                  "expression": {
+                    "argumentTypes": null,
+                    "baseExpression": {
+                      "argumentTypes": null,
+                      "id": 1147,
+                      "name": "_ownedTokens",
+                      "nodeType": "Identifier",
+                      "overloadedDeclarations": [],
+                      "referencedDeclaration": 981,
+                      "src": "29299:12:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_mapping$_t_address_$_t_array$_t_uint256_$dyn_storage_$",
+                        "typeString": "mapping(address => uint256[] storage ref)"
+                      }
+                    },
+                    "id": 1149,
+                    "indexExpression": {
+                      "argumentTypes": null,
+                      "id": 1148,
+                      "name": "owner",
+                      "nodeType": "Identifier",
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+                      "referencedDeclaration": 1141,
+                      "src": "29312:5:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_address",
+                        "typeString": "address"
+                      }
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+                    "isLValue": true,
+                    "isPure": false,
+                    "lValueRequested": false,
+                    "nodeType": "IndexAccess",
+                    "src": "29299:19:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_array$_t_uint256_$dyn_storage",
+                      "typeString": "uint256[] storage ref"
+                    }
+                  },
+                  "functionReturnParameters": 1146,
+                  "id": 1150,
+                  "nodeType": "Return",
+                  "src": "29292:26:1"
+                }
+              ]
+            },
+            "documentation": "@dev Gets the list of token IDs of the requested owner.\n@param owner address owning the tokens\n@return uint256[] List of token IDs owned by the requested address",
+            "id": 1152,
+            "implemented": true,
+            "kind": "function",
+            "modifiers": [],
+            "name": "_tokensOfOwner",
+            "nodeType": "FunctionDefinition",
+            "parameters": {
+              "id": 1142,
+              "nodeType": "ParameterList",
+              "parameters": [
+                {
+                  "constant": false,
+                  "id": 1141,
+                  "name": "owner",
+                  "nodeType": "VariableDeclaration",
+                  "scope": 1152,
+                  "src": "29225:13:1",
+                  "stateVariable": false,
+                  "storageLocation": "default",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_address",
+                    "typeString": "address"
+                  },
+                  "typeName": {
+                    "id": 1140,
+                    "name": "address",
+                    "nodeType": "ElementaryTypeName",
+                    "src": "29225:7:1",
+                    "stateMutability": "nonpayable",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_address",
+                      "typeString": "address"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                }
+              ],
+              "src": "29224:15:1"
+            },
+            "returnParameters": {
+              "id": 1146,
+              "nodeType": "ParameterList",
+              "parameters": [
+                {
+                  "constant": false,
+                  "id": 1145,
+                  "name": "",
+                  "nodeType": "VariableDeclaration",
+                  "scope": 1152,
+                  "src": "29263:17:1",
+                  "stateVariable": false,
+                  "storageLocation": "storage",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_array$_t_uint256_$dyn_storage_ptr",
+                    "typeString": "uint256[]"
+                  },
+                  "typeName": {
+                    "baseType": {
+                      "id": 1143,
+                      "name": "uint256",
+                      "nodeType": "ElementaryTypeName",
+                      "src": "29263:7:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_uint256",
+                        "typeString": "uint256"
+                      }
+                    },
+                    "id": 1144,
+                    "length": null,
+                    "nodeType": "ArrayTypeName",
+                    "src": "29263:9:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_array$_t_uint256_$dyn_storage_ptr",
+                      "typeString": "uint256[]"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                }
+              ],
+              "src": "29262:19:1"
+            },
+            "scope": 1302,
+            "src": "29201:124:1",
+            "stateMutability": "view",
+            "superFunction": null,
+            "visibility": "internal"
+          },
+          {
+            "body": {
+              "id": 1175,
+              "nodeType": "Block",
+              "src": "29693:109:1",
+              "statements": [
+                {
+                  "expression": {
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+                    "id": 1166,
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+                    "isLValue": false,
+                    "isPure": false,
+                    "lValueRequested": false,
+                    "leftHandSide": {
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+                      "baseExpression": {
+                        "argumentTypes": null,
+                        "id": 1159,
+                        "name": "_ownedTokensIndex",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 985,
+                        "src": "29703:17:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_mapping$_t_uint256_$_t_uint256_$",
+                          "typeString": "mapping(uint256 => uint256)"
+                        }
+                      },
+                      "id": 1161,
+                      "indexExpression": {
+                        "argumentTypes": null,
+                        "id": 1160,
+                        "name": "tokenId",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 1156,
+                        "src": "29721:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
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+                      "isLValue": true,
+                      "isPure": false,
+                      "lValueRequested": true,
+                      "nodeType": "IndexAccess",
+                      "src": "29703:26:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_uint256",
+                        "typeString": "uint256"
+                      }
+                    },
+                    "nodeType": "Assignment",
+                    "operator": "=",
+                    "rightHandSide": {
+                      "argumentTypes": null,
+                      "expression": {
+                        "argumentTypes": null,
+                        "baseExpression": {
+                          "argumentTypes": null,
+                          "id": 1162,
+                          "name": "_ownedTokens",
+                          "nodeType": "Identifier",
+                          "overloadedDeclarations": [],
+                          "referencedDeclaration": 981,
+                          "src": "29732:12:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_mapping$_t_address_$_t_array$_t_uint256_$dyn_storage_$",
+                            "typeString": "mapping(address => uint256[] storage ref)"
+                          }
+                        },
+                        "id": 1164,
+                        "indexExpression": {
+                          "argumentTypes": null,
+                          "id": 1163,
+                          "name": "to",
+                          "nodeType": "Identifier",
+                          "overloadedDeclarations": [],
+                          "referencedDeclaration": 1154,
+                          "src": "29745:2:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_address",
+                            "typeString": "address"
+                          }
+                        },
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+                              "typeDescriptions": {
+                                "typeIdentifier": "t_mapping$_t_address_$_t_array$_t_uint256_$dyn_storage_$",
+                                "typeString": "mapping(address => uint256[] storage ref)"
+                              }
+                            },
+                            "id": 1225,
+                            "indexExpression": {
+                              "argumentTypes": null,
+                              "id": 1224,
+                              "name": "from",
+                              "nodeType": "Identifier",
+                              "overloadedDeclarations": [],
+                              "referencedDeclaration": 1197,
+                              "src": "31332:4:1",
+                              "typeDescriptions": {
+                                "typeIdentifier": "t_address",
+                                "typeString": "address"
+                              }
+                            },
+                            "isConstant": false,
+                            "isLValue": true,
+                            "isPure": false,
+                            "lValueRequested": false,
+                            "nodeType": "IndexAccess",
+                            "src": "31319:18:1",
+                            "typeDescriptions": {
+                              "typeIdentifier": "t_array$_t_uint256_$dyn_storage",
+                              "typeString": "uint256[] storage ref"
+                            }
+                          },
+                          "id": 1227,
+                          "indexExpression": {
+                            "argumentTypes": null,
+                            "id": 1226,
+                            "name": "lastTokenIndex",
+                            "nodeType": "Identifier",
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+                            "referencedDeclaration": 1203,
+                            "src": "31338:14:1",
+                            "typeDescriptions": {
+                              "typeIdentifier": "t_uint256",
+                              "typeString": "uint256"
+                            }
+                          },
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+                          "isLValue": true,
+                          "isPure": false,
+                          "lValueRequested": false,
+                          "nodeType": "IndexAccess",
+                          "src": "31319:34:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_uint256",
+                            "typeString": "uint256"
+                          }
+                        },
+                        "nodeType": "VariableDeclarationStatement",
+                        "src": "31297:56:1"
+                      },
+                      {
+                        "expression": {
+                          "argumentTypes": null,
+                          "id": 1235,
+                          "isConstant": false,
+                          "isLValue": false,
+                          "isPure": false,
+                          "lValueRequested": false,
+                          "leftHandSide": {
+                            "argumentTypes": null,
+                            "baseExpression": {
+                              "argumentTypes": null,
+                              "baseExpression": {
+                                "argumentTypes": null,
+                                "id": 1229,
+                                "name": "_ownedTokens",
+                                "nodeType": "Identifier",
+                                "overloadedDeclarations": [],
+                                "referencedDeclaration": 981,
+                                "src": "31368:12:1",
+                                "typeDescriptions": {
+                                  "typeIdentifier": "t_mapping$_t_address_$_t_array$_t_uint256_$dyn_storage_$",
+                                  "typeString": "mapping(address => uint256[] storage ref)"
+                                }
+                              },
+                              "id": 1232,
+                              "indexExpression": {
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+                                "id": 1230,
+                                "name": "from",
+                                "nodeType": "Identifier",
+                                "overloadedDeclarations": [],
+                                "referencedDeclaration": 1197,
+                                "src": "31381:4:1",
+                                "typeDescriptions": {
+                                  "typeIdentifier": "t_address",
+                                  "typeString": "address"
+                                }
+                              },
+                              "isConstant": false,
+                              "isLValue": true,
+                              "isPure": false,
+                              "lValueRequested": false,
+                              "nodeType": "IndexAccess",
+                              "src": "31368:18:1",
+                              "typeDescriptions": {
+                                "typeIdentifier": "t_array$_t_uint256_$dyn_storage",
+                                "typeString": "uint256[] storage ref"
+                              }
+                            },
+                            "id": 1233,
+                            "indexExpression": {
+                              "argumentTypes": null,
+                              "id": 1231,
+                              "name": "tokenIndex",
+                              "nodeType": "Identifier",
+                              "overloadedDeclarations": [],
+                              "referencedDeclaration": 1213,
+                              "src": "31387:10:1",
+                              "typeDescriptions": {
+                                "typeIdentifier": "t_uint256",
+                                "typeString": "uint256"
+                              }
+                            },
+                            "isConstant": false,
+                            "isLValue": true,
+                            "isPure": false,
+                            "lValueRequested": true,
+                            "nodeType": "IndexAccess",
+                            "src": "31368:30:1",
+                            "typeDescriptions": {
+                              "typeIdentifier": "t_uint256",
+                              "typeString": "uint256"
+                            }
+                          },
+                          "nodeType": "Assignment",
+                          "operator": "=",
+                          "rightHandSide": {
+                            "argumentTypes": null,
+                            "id": 1234,
+                            "name": "lastTokenId",
+                            "nodeType": "Identifier",
+                            "overloadedDeclarations": [],
+                            "referencedDeclaration": 1222,
+                            "src": "31401:11:1",
+                            "typeDescriptions": {
+                              "typeIdentifier": "t_uint256",
+                              "typeString": "uint256"
+                            }
+                          },
+                          "src": "31368:44:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_uint256",
+                            "typeString": "uint256"
+                          }
+                        },
+                        "id": 1236,
+                        "nodeType": "ExpressionStatement",
+                        "src": "31368:44:1"
+                      },
+                      {
+                        "expression": {
+                          "argumentTypes": null,
+                          "id": 1241,
+                          "isConstant": false,
+                          "isLValue": false,
+                          "isPure": false,
+                          "lValueRequested": false,
+                          "leftHandSide": {
+                            "argumentTypes": null,
+                            "baseExpression": {
+                              "argumentTypes": null,
+                              "id": 1237,
+                              "name": "_ownedTokensIndex",
+                              "nodeType": "Identifier",
+                              "overloadedDeclarations": [],
+                              "referencedDeclaration": 985,
+                              "src": "31484:17:1",
+                              "typeDescriptions": {
+                                "typeIdentifier": "t_mapping$_t_uint256_$_t_uint256_$",
+                                "typeString": "mapping(uint256 => uint256)"
+                              }
+                            },
+                            "id": 1239,
+                            "indexExpression": {
+                              "argumentTypes": null,
+                              "id": 1238,
+                              "name": "lastTokenId",
+                              "nodeType": "Identifier",
+                              "overloadedDeclarations": [],
+                              "referencedDeclaration": 1222,
+                              "src": "31502:11:1",
+                              "typeDescriptions": {
+                                "typeIdentifier": "t_uint256",
+                                "typeString": "uint256"
+                              }
+                            },
+                            "isConstant": false,
+                            "isLValue": true,
+                            "isPure": false,
+                            "lValueRequested": true,
+                            "nodeType": "IndexAccess",
+                            "src": "31484:30:1",
+                            "typeDescriptions": {
+                              "typeIdentifier": "t_uint256",
+                              "typeString": "uint256"
+                            }
+                          },
+                          "nodeType": "Assignment",
+                          "operator": "=",
+                          "rightHandSide": {
+                            "argumentTypes": null,
+                            "id": 1240,
+                            "name": "tokenIndex",
+                            "nodeType": "Identifier",
+                            "overloadedDeclarations": [],
+                            "referencedDeclaration": 1213,
+                            "src": "31517:10:1",
+                            "typeDescriptions": {
+                              "typeIdentifier": "t_uint256",
+                              "typeString": "uint256"
+                            }
+                          },
+                          "src": "31484:43:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_uint256",
+                            "typeString": "uint256"
+                          }
+                        },
+                        "id": 1242,
+                        "nodeType": "ExpressionStatement",
+                        "src": "31484:43:1"
+                      }
+                    ]
+                  }
+                },
+                {
+                  "expression": {
+                    "argumentTypes": null,
+                    "id": 1249,
+                    "isConstant": false,
+                    "isLValue": false,
+                    "isPure": false,
+                    "lValueRequested": false,
+                    "nodeType": "UnaryOperation",
+                    "operator": "--",
+                    "prefix": false,
+                    "src": "31658:27:1",
+                    "subExpression": {
+                      "argumentTypes": null,
+                      "expression": {
+                        "argumentTypes": null,
+                        "baseExpression": {
+                          "argumentTypes": null,
+                          "id": 1245,
+                          "name": "_ownedTokens",
+                          "nodeType": "Identifier",
+                          "overloadedDeclarations": [],
+                          "referencedDeclaration": 981,
+                          "src": "31658:12:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_mapping$_t_address_$_t_array$_t_uint256_$dyn_storage_$",
+                            "typeString": "mapping(address => uint256[] storage ref)"
+                          }
+                        },
+                        "id": 1247,
+                        "indexExpression": {
+                          "argumentTypes": null,
+                          "id": 1246,
+                          "name": "from",
+                          "nodeType": "Identifier",
+                          "overloadedDeclarations": [],
+                          "referencedDeclaration": 1197,
+                          "src": "31671:4:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_address",
+                            "typeString": "address"
+                          }
+                        },
+                        "isConstant": false,
+                        "isLValue": true,
+                        "isPure": false,
+                        "lValueRequested": false,
+                        "nodeType": "IndexAccess",
+                        "src": "31658:18:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_array$_t_uint256_$dyn_storage",
+                          "typeString": "uint256[] storage ref"
+                        }
+                      },
+                      "id": 1248,
+                      "isConstant": false,
+                      "isLValue": true,
+                      "isPure": false,
+                      "lValueRequested": true,
+                      "memberName": "length",
+                      "nodeType": "MemberAccess",
+                      "referencedDeclaration": null,
+                      "src": "31658:25:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_uint256",
+                        "typeString": "uint256"
+                      }
+                    },
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_uint256",
+                      "typeString": "uint256"
+                    }
+                  },
+                  "id": 1250,
+                  "nodeType": "ExpressionStatement",
+                  "src": "31658:27:1"
+                }
+              ]
+            },
+            "documentation": "@dev Private function to remove a token from this extension's ownership-tracking data structures. Note that\nwhile the token is not assigned a new owner, the _ownedTokensIndex mapping is _not_ updated: this allows for\ngas optimizations e.g. when performing a transfer operation (avoiding double writes).\nThis has O(1) time complexity, but alters the order of the _ownedTokens array.\n@param from address representing the previous owner of the given token ID\n@param tokenId uint256 ID of the token to be removed from the tokens list of the given address",
+            "id": 1252,
+            "implemented": true,
+            "kind": "function",
+            "modifiers": [],
+            "name": "_removeTokenFromOwnerEnumeration",
+            "nodeType": "FunctionDefinition",
+            "parameters": {
+              "id": 1200,
+              "nodeType": "ParameterList",
+              "parameters": [
+                {
+                  "constant": false,
+                  "id": 1197,
+                  "name": "from",
+                  "nodeType": "VariableDeclaration",
+                  "scope": 1252,
+                  "src": "30815:12:1",
+                  "stateVariable": false,
+                  "storageLocation": "default",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_address",
+                    "typeString": "address"
+                  },
+                  "typeName": {
+                    "id": 1196,
+                    "name": "address",
+                    "nodeType": "ElementaryTypeName",
+                    "src": "30815:7:1",
+                    "stateMutability": "nonpayable",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_address",
+                      "typeString": "address"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                },
+                {
+                  "constant": false,
+                  "id": 1199,
+                  "name": "tokenId",
+                  "nodeType": "VariableDeclaration",
+                  "scope": 1252,
+                  "src": "30829:15:1",
+                  "stateVariable": false,
+                  "storageLocation": "default",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_uint256",
+                    "typeString": "uint256"
+                  },
+                  "typeName": {
+                    "id": 1198,
+                    "name": "uint256",
+                    "nodeType": "ElementaryTypeName",
+                    "src": "30829:7:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_uint256",
+                      "typeString": "uint256"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                }
+              ],
+              "src": "30814:31:1"
+            },
+            "returnParameters": {
+              "id": 1201,
+              "nodeType": "ParameterList",
+              "parameters": [],
+              "src": "30854:0:1"
+            },
+            "scope": 1302,
+            "src": "30773:1128:1",
+            "stateMutability": "nonpayable",
+            "superFunction": null,
+            "visibility": "private"
+          },
+          {
+            "body": {
+              "id": 1300,
+              "nodeType": "Block",
+              "src": "32260:993:1",
+              "statements": [
+                {
+                  "assignments": [
+                    1258
+                  ],
+                  "declarations": [
+                    {
+                      "constant": false,
+                      "id": 1258,
+                      "name": "lastTokenIndex",
+                      "nodeType": "VariableDeclaration",
+                      "scope": 1300,
+                      "src": "32438:22:1",
+                      "stateVariable": false,
+                      "storageLocation": "default",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_uint256",
+                        "typeString": "uint256"
+                      },
+                      "typeName": {
+                        "id": 1257,
+                        "name": "uint256",
+                        "nodeType": "ElementaryTypeName",
+                        "src": "32438:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      },
+                      "value": null,
+                      "visibility": "internal"
+                    }
+                  ],
+                  "id": 1264,
+                  "initialValue": {
+                    "argumentTypes": null,
+                    "arguments": [
+                      {
+                        "argumentTypes": null,
+                        "hexValue": "31",
+                        "id": 1262,
+                        "isConstant": false,
+                        "isLValue": false,
+                        "isPure": true,
+                        "kind": "number",
+                        "lValueRequested": false,
+                        "nodeType": "Literal",
+                        "src": "32485:1:1",
+                        "subdenomination": null,
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_rational_1_by_1",
+                          "typeString": "int_const 1"
+                        },
+                        "value": "1"
+                      }
+                    ],
+                    "expression": {
+                      "argumentTypes": [
+                        {
+                          "typeIdentifier": "t_rational_1_by_1",
+                          "typeString": "int_const 1"
+                        }
+                      ],
+                      "expression": {
+                        "argumentTypes": null,
+                        "expression": {
+                          "argumentTypes": null,
+                          "id": 1259,
+                          "name": "_allTokens",
+                          "nodeType": "Identifier",
+                          "overloadedDeclarations": [],
+                          "referencedDeclaration": 988,
+                          "src": "32463:10:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_array$_t_uint256_$dyn_storage",
+                            "typeString": "uint256[] storage ref"
+                          }
+                        },
+                        "id": 1260,
+                        "isConstant": false,
+                        "isLValue": true,
+                        "isPure": false,
+                        "lValueRequested": false,
+                        "memberName": "length",
+                        "nodeType": "MemberAccess",
+                        "referencedDeclaration": null,
+                        "src": "32463:17:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      },
+                      "id": 1261,
+                      "isConstant": false,
+                      "isLValue": false,
+                      "isPure": false,
+                      "lValueRequested": false,
+                      "memberName": "sub",
+                      "nodeType": "MemberAccess",
+                      "referencedDeclaration": 190,
+                      "src": "32463:21:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_function_internal_pure$_t_uint256_$_t_uint256_$returns$_t_uint256_$bound_to$_t_uint256_$",
+                        "typeString": "function (uint256,uint256) pure returns (uint256)"
+                      }
+                    },
+                    "id": 1263,
+                    "isConstant": false,
+                    "isLValue": false,
+                    "isPure": false,
+                    "kind": "functionCall",
+                    "lValueRequested": false,
+                    "names": [],
+                    "nodeType": "FunctionCall",
+                    "src": "32463:24:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_uint256",
+                      "typeString": "uint256"
+                    }
+                  },
+                  "nodeType": "VariableDeclarationStatement",
+                  "src": "32438:49:1"
+                },
+                {
+                  "assignments": [
+                    1266
+                  ],
+                  "declarations": [
+                    {
+                      "constant": false,
+                      "id": 1266,
+                      "name": "tokenIndex",
+                      "nodeType": "VariableDeclaration",
+                      "scope": 1300,
+                      "src": "32497:18:1",
+                      "stateVariable": false,
+                      "storageLocation": "default",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_uint256",
+                        "typeString": "uint256"
+                      },
+                      "typeName": {
+                        "id": 1265,
+                        "name": "uint256",
+                        "nodeType": "ElementaryTypeName",
+                        "src": "32497:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      },
+                      "value": null,
+                      "visibility": "internal"
+                    }
+                  ],
+                  "id": 1270,
+                  "initialValue": {
+                    "argumentTypes": null,
+                    "baseExpression": {
+                      "argumentTypes": null,
+                      "id": 1267,
+                      "name": "_allTokensIndex",
+                      "nodeType": "Identifier",
+                      "overloadedDeclarations": [],
+                      "referencedDeclaration": 992,
+                      "src": "32518:15:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_mapping$_t_uint256_$_t_uint256_$",
+                        "typeString": "mapping(uint256 => uint256)"
+                      }
+                    },
+                    "id": 1269,
+                    "indexExpression": {
+                      "argumentTypes": null,
+                      "id": 1268,
+                      "name": "tokenId",
+                      "nodeType": "Identifier",
+                      "overloadedDeclarations": [],
+                      "referencedDeclaration": 1254,
+                      "src": "32534:7:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_uint256",
+                        "typeString": "uint256"
+                      }
+                    },
+                    "isConstant": false,
+                    "isLValue": true,
+                    "isPure": false,
+                    "lValueRequested": false,
+                    "nodeType": "IndexAccess",
+                    "src": "32518:24:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_uint256",
+                      "typeString": "uint256"
+                    }
+                  },
+                  "nodeType": "VariableDeclarationStatement",
+                  "src": "32497:45:1"
+                },
+                {
+                  "assignments": [
+                    1272
+                  ],
+                  "declarations": [
+                    {
+                      "constant": false,
+                      "id": 1272,
+                      "name": "lastTokenId",
+                      "nodeType": "VariableDeclaration",
+                      "scope": 1300,
+                      "src": "32864:19:1",
+                      "stateVariable": false,
+                      "storageLocation": "default",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_uint256",
+                        "typeString": "uint256"
+                      },
+                      "typeName": {
+                        "id": 1271,
+                        "name": "uint256",
+                        "nodeType": "ElementaryTypeName",
+                        "src": "32864:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      },
+                      "value": null,
+                      "visibility": "internal"
+                    }
+                  ],
+                  "id": 1276,
+                  "initialValue": {
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+                    "baseExpression": {
+                      "argumentTypes": null,
+                      "id": 1273,
+                      "name": "_allTokens",
+                      "nodeType": "Identifier",
+                      "overloadedDeclarations": [],
+                      "referencedDeclaration": 988,
+                      "src": "32886:10:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_array$_t_uint256_$dyn_storage",
+                        "typeString": "uint256[] storage ref"
+                      }
+                    },
+                    "id": 1275,
+                    "indexExpression": {
+                      "argumentTypes": null,
+                      "id": 1274,
+                      "name": "lastTokenIndex",
+                      "nodeType": "Identifier",
+                      "overloadedDeclarations": [],
+                      "referencedDeclaration": 1258,
+                      "src": "32897:14:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_uint256",
+                        "typeString": "uint256"
+                      }
+                    },
+                    "isConstant": false,
+                    "isLValue": true,
+                    "isPure": false,
+                    "lValueRequested": false,
+                    "nodeType": "IndexAccess",
+                    "src": "32886:26:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_uint256",
+                      "typeString": "uint256"
+                    }
+                  },
+                  "nodeType": "VariableDeclarationStatement",
+                  "src": "32864:48:1"
+                },
+                {
+                  "expression": {
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+                    "id": 1281,
+                    "isConstant": false,
+                    "isLValue": false,
+                    "isPure": false,
+                    "lValueRequested": false,
+                    "leftHandSide": {
+                      "argumentTypes": null,
+                      "baseExpression": {
+                        "argumentTypes": null,
+                        "id": 1277,
+                        "name": "_allTokens",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 988,
+                        "src": "32923:10:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_array$_t_uint256_$dyn_storage",
+                          "typeString": "uint256[] storage ref"
+                        }
+                      },
+                      "id": 1279,
+                      "indexExpression": {
+                        "argumentTypes": null,
+                        "id": 1278,
+                        "name": "tokenIndex",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 1266,
+                        "src": "32934:10:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      },
+                      "isConstant": false,
+                      "isLValue": true,
+                      "isPure": false,
+                      "lValueRequested": true,
+                      "nodeType": "IndexAccess",
+                      "src": "32923:22:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_uint256",
+                        "typeString": "uint256"
+                      }
+                    },
+                    "nodeType": "Assignment",
+                    "operator": "=",
+                    "rightHandSide": {
+                      "argumentTypes": null,
+                      "id": 1280,
+                      "name": "lastTokenId",
+                      "nodeType": "Identifier",
+                      "overloadedDeclarations": [],
+                      "referencedDeclaration": 1272,
+                      "src": "32948:11:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_uint256",
+                        "typeString": "uint256"
+                      }
+                    },
+                    "src": "32923:36:1",
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+              "name": "IERC165",
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+                "typeString": "contract IERC165"
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+                          "typeString": "bytes memory"
+                        }
+                      }
+                    ],
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+                          "typeString": "address payable"
+                        },
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+                          "typeString": "address"
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+                            }
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+                          "name": "IERC721Receiver",
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+                          "src": "23593:15:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_type$_t_contract$_IERC721Receiver_$139_$",
+                            "typeString": "type(contract IERC721Receiver)"
+                          }
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+                          "typeDescriptions": {
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+                            "typeString": "bytes4"
+                          }
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+              ]
+            },
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+                        "src": "23940:15:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_mapping$_t_uint256_$_t_address_$",
+                          "typeString": "mapping(uint256 => address)"
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+                              "src": "23994:15:1",
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+                                "kind": "number",
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+                                "nodeType": "Literal",
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+                                  "typeString": "int_const 0"
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+                            ],
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+                              "isConstant": false,
+                              "isLValue": false,
+                              "isPure": true,
+                              "lValueRequested": false,
+                              "nodeType": "ElementaryTypeNameExpression",
+                              "src": "24021:7:1",
+                              "typeDescriptions": {
+                                "typeIdentifier": "t_type$_t_address_$",
+                                "typeString": "type(address)"
+                              },
+                              "typeName": "address"
+                            },
+                            "id": 937,
+                            "isConstant": false,
+                            "isLValue": false,
+                            "isPure": true,
+                            "kind": "typeConversion",
+                            "lValueRequested": false,
+                            "names": [],
+                            "nodeType": "FunctionCall",
+                            "src": "24021:10:1",
+                            "typeDescriptions": {
+                              "typeIdentifier": "t_address_payable",
+                              "typeString": "address payable"
+                            }
+                          },
+                          "src": "23994:37:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_address",
+                            "typeString": "address"
+                          }
+                        },
+                        "id": 939,
+                        "nodeType": "ExpressionStatement",
+                        "src": "23994:37:1"
+                      }
+                    ]
+                  }
+                }
+              ]
+            },
+            "documentation": "@dev Private function to clear current approval of a given token ID.\n@param tokenId uint256 ID of the token to be transferred",
+            "id": 943,
+            "implemented": true,
+            "kind": "function",
+            "modifiers": [],
+            "name": "_clearApproval",
+            "nodeType": "FunctionDefinition",
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+              "nodeType": "ParameterList",
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+                  "stateVariable": false,
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+                    "name": "uint256",
+                    "nodeType": "ElementaryTypeName",
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+                      "typeString": "uint256"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                }
+              ],
+              "src": "23900:17:1"
+            },
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+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      }
+                    ],
+                    "expression": {
+                      "argumentTypes": [
+                        {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      ],
+                      "id": 1134,
+                      "name": "_removeTokenFromAllTokensEnumeration",
+                      "nodeType": "Identifier",
+                      "overloadedDeclarations": [],
+                      "referencedDeclaration": 1301,
+                      "src": "28944:36:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_function_internal_nonpayable$_t_uint256_$returns$__$",
+                        "typeString": "function (uint256)"
+                      }
+                    },
+                    "id": 1136,
+                    "isConstant": false,
+                    "isLValue": false,
+                    "isPure": false,
+                    "kind": "functionCall",
+                    "lValueRequested": false,
+                    "names": [],
+                    "nodeType": "FunctionCall",
+                    "src": "28944:45:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_tuple$__$",
+                      "typeString": "tuple()"
+                    }
+                  },
+                  "id": 1137,
+                  "nodeType": "ExpressionStatement",
+                  "src": "28944:45:1"
+                }
+              ]
+            },
+            "documentation": "@dev Internal function to burn a specific token.\nReverts if the token does not exist.\nDeprecated, use _burn(uint256) instead.\n@param owner owner of the token to burn\n@param tokenId uint256 ID of the token being burned",
+            "id": 1139,
+            "implemented": true,
+            "kind": "function",
+            "modifiers": [],
+            "name": "_burn",
+            "nodeType": "FunctionDefinition",
+            "parameters": {
+              "id": 1114,
+              "nodeType": "ParameterList",
+              "parameters": [
+                {
+                  "constant": false,
+                  "id": 1111,
+                  "name": "owner",
+                  "nodeType": "VariableDeclaration",
+                  "scope": 1139,
+                  "src": "28647:13:1",
+                  "stateVariable": false,
+                  "storageLocation": "default",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_address",
+                    "typeString": "address"
+                  },
+                  "typeName": {
+                    "id": 1110,
+                    "name": "address",
+                    "nodeType": "ElementaryTypeName",
+                    "src": "28647:7:1",
+                    "stateMutability": "nonpayable",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_address",
+                      "typeString": "address"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                },
+                {
+                  "constant": false,
+                  "id": 1113,
+                  "name": "tokenId",
+                  "nodeType": "VariableDeclaration",
+                  "scope": 1139,
+                  "src": "28662:15:1",
+                  "stateVariable": false,
+                  "storageLocation": "default",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_uint256",
+                    "typeString": "uint256"
+                  },
+                  "typeName": {
+                    "id": 1112,
+                    "name": "uint256",
+                    "nodeType": "ElementaryTypeName",
+                    "src": "28662:7:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_uint256",
+                      "typeString": "uint256"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                }
+              ],
+              "src": "28646:32:1"
+            },
+            "returnParameters": {
+              "id": 1115,
+              "nodeType": "ParameterList",
+              "parameters": [],
+              "src": "28688:0:1"
+            },
+            "scope": 1302,
+            "src": "28632:364:1",
+            "stateMutability": "nonpayable",
+            "superFunction": 811,
+            "visibility": "internal"
+          },
+          {
+            "body": {
+              "id": 1151,
+              "nodeType": "Block",
+              "src": "29282:43:1",
+              "statements": [
+                {
+                  "expression": {
+                    "argumentTypes": null,
+                    "baseExpression": {
+                      "argumentTypes": null,
+                      "id": 1147,
+                      "name": "_ownedTokens",
+                      "nodeType": "Identifier",
+                      "overloadedDeclarations": [],
+                      "referencedDeclaration": 981,
+                      "src": "29299:12:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_mapping$_t_address_$_t_array$_t_uint256_$dyn_storage_$",
+                        "typeString": "mapping(address => uint256[] storage ref)"
+                      }
+                    },
+                    "id": 1149,
+                    "indexExpression": {
+                      "argumentTypes": null,
+                      "id": 1148,
+                      "name": "owner",
+                      "nodeType": "Identifier",
+                      "overloadedDeclarations": [],
+                      "referencedDeclaration": 1141,
+                      "src": "29312:5:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_address",
+                        "typeString": "address"
+                      }
+                    },
+                    "isConstant": false,
+                    "isLValue": true,
+                    "isPure": false,
+                    "lValueRequested": false,
+                    "nodeType": "IndexAccess",
+                    "src": "29299:19:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_array$_t_uint256_$dyn_storage",
+                      "typeString": "uint256[] storage ref"
+                    }
+                  },
+                  "functionReturnParameters": 1146,
+                  "id": 1150,
+                  "nodeType": "Return",
+                  "src": "29292:26:1"
+                }
+              ]
+            },
+            "documentation": "@dev Gets the list of token IDs of the requested owner.\n@param owner address owning the tokens\n@return uint256[] List of token IDs owned by the requested address",
+            "id": 1152,
+            "implemented": true,
+            "kind": "function",
+            "modifiers": [],
+            "name": "_tokensOfOwner",
+            "nodeType": "FunctionDefinition",
+            "parameters": {
+              "id": 1142,
+              "nodeType": "ParameterList",
+              "parameters": [
+                {
+                  "constant": false,
+                  "id": 1141,
+                  "name": "owner",
+                  "nodeType": "VariableDeclaration",
+                  "scope": 1152,
+                  "src": "29225:13:1",
+                  "stateVariable": false,
+                  "storageLocation": "default",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_address",
+                    "typeString": "address"
+                  },
+                  "typeName": {
+                    "id": 1140,
+                    "name": "address",
+                    "nodeType": "ElementaryTypeName",
+                    "src": "29225:7:1",
+                    "stateMutability": "nonpayable",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_address",
+                      "typeString": "address"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                }
+              ],
+              "src": "29224:15:1"
+            },
+            "returnParameters": {
+              "id": 1146,
+              "nodeType": "ParameterList",
+              "parameters": [
+                {
+                  "constant": false,
+                  "id": 1145,
+                  "name": "",
+                  "nodeType": "VariableDeclaration",
+                  "scope": 1152,
+                  "src": "29263:17:1",
+                  "stateVariable": false,
+                  "storageLocation": "storage",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_array$_t_uint256_$dyn_storage_ptr",
+                    "typeString": "uint256[]"
+                  },
+                  "typeName": {
+                    "baseType": {
+                      "id": 1143,
+                      "name": "uint256",
+                      "nodeType": "ElementaryTypeName",
+                      "src": "29263:7:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_uint256",
+                        "typeString": "uint256"
+                      }
+                    },
+                    "id": 1144,
+                    "length": null,
+                    "nodeType": "ArrayTypeName",
+                    "src": "29263:9:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_array$_t_uint256_$dyn_storage_ptr",
+                      "typeString": "uint256[]"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                }
+              ],
+              "src": "29262:19:1"
+            },
+            "scope": 1302,
+            "src": "29201:124:1",
+            "stateMutability": "view",
+            "superFunction": null,
+            "visibility": "internal"
+          },
+          {
+            "body": {
+              "id": 1175,
+              "nodeType": "Block",
+              "src": "29693:109:1",
+              "statements": [
+                {
+                  "expression": {
+                    "argumentTypes": null,
+                    "id": 1166,
+                    "isConstant": false,
+                    "isLValue": false,
+                    "isPure": false,
+                    "lValueRequested": false,
+                    "leftHandSide": {
+                      "argumentTypes": null,
+                      "baseExpression": {
+                        "argumentTypes": null,
+                        "id": 1159,
+                        "name": "_ownedTokensIndex",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 985,
+                        "src": "29703:17:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_mapping$_t_uint256_$_t_uint256_$",
+                          "typeString": "mapping(uint256 => uint256)"
+                        }
+                      },
+                      "id": 1161,
+                      "indexExpression": {
+                        "argumentTypes": null,
+                        "id": 1160,
+                        "name": "tokenId",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 1156,
+                        "src": "29721:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      },
+                      "isConstant": false,
+                      "isLValue": true,
+                      "isPure": false,
+                      "lValueRequested": true,
+                      "nodeType": "IndexAccess",
+                      "src": "29703:26:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_uint256",
+                        "typeString": "uint256"
+                      }
+                    },
+                    "nodeType": "Assignment",
+                    "operator": "=",
+                    "rightHandSide": {
+                      "argumentTypes": null,
+                      "expression": {
+                        "argumentTypes": null,
+                        "baseExpression": {
+                          "argumentTypes": null,
+                          "id": 1162,
+                          "name": "_ownedTokens",
+                          "nodeType": "Identifier",
+                          "overloadedDeclarations": [],
+                          "referencedDeclaration": 981,
+                          "src": "29732:12:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_mapping$_t_address_$_t_array$_t_uint256_$dyn_storage_$",
+                            "typeString": "mapping(address => uint256[] storage ref)"
+                          }
+                        },
+                        "id": 1164,
+                        "indexExpression": {
+                          "argumentTypes": null,
+                          "id": 1163,
+                          "name": "to",
+                          "nodeType": "Identifier",
+                          "overloadedDeclarations": [],
+                          "referencedDeclaration": 1154,
+                          "src": "29745:2:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_address",
+                            "typeString": "address"
+                          }
+                        },
+                        "isConstant": false,
+                        "isLValue": true,
+                        "isPure": false,
+                        "lValueRequested": false,
+                        "nodeType": "IndexAccess",
+                        "src": "29732:16:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_array$_t_uint256_$dyn_storage",
+                          "typeString": "uint256[] storage ref"
+                        }
+                      },
+                      "id": 1165,
+                      "isConstant": false,
+                      "isLValue": true,
+                      "isPure": false,
+                      "lValueRequested": false,
+                      "memberName": "length",
+                      "nodeType": "MemberAccess",
+                      "referencedDeclaration": null,
+                      "src": "29732:23:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_uint256",
+                        "typeString": "uint256"
+                      }
+                    },
+                    "src": "29703:52:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_uint256",
+                      "typeString": "uint256"
+                    }
+                  },
+                  "id": 1167,
+                  "nodeType": "ExpressionStatement",
+                  "src": "29703:52:1"
+                },
+                {
+                  "expression": {
+                    "argumentTypes": null,
+                    "arguments": [
+                      {
+                        "argumentTypes": null,
+                        "id": 1172,
+                        "name": "tokenId",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 1156,
+                        "src": "29787:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      }
+                    ],
+                    "expression": {
+                      "argumentTypes": [
+                        {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      ],
+                      "expression": {
+                        "argumentTypes": null,
+                        "baseExpression": {
+                          "argumentTypes": null,
+                          "id": 1168,
+                          "name": "_ownedTokens",
+                          "nodeType": "Identifier",
+                          "overloadedDeclarations": [],
+                          "referencedDeclaration": 981,
+                          "src": "29765:12:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_mapping$_t_address_$_t_array$_t_uint256_$dyn_storage_$",
+                            "typeString": "mapping(address => uint256[] storage ref)"
+                          }
+                        },
+                        "id": 1170,
+                        "indexExpression": {
+                          "argumentTypes": null,
+                          "id": 1169,
+                          "name": "to",
+                          "nodeType": "Identifier",
+                          "overloadedDeclarations": [],
+                          "referencedDeclaration": 1154,
+                          "src": "29778:2:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_address",
+                            "typeString": "address"
+                          }
+                        },
+                        "isConstant": false,
+                        "isLValue": true,
+                        "isPure": false,
+                        "lValueRequested": false,
+                        "nodeType": "IndexAccess",
+                        "src": "29765:16:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_array$_t_uint256_$dyn_storage",
+                          "typeString": "uint256[] storage ref"
+                        }
+                      },
+                      "id": 1171,
+                      "isConstant": false,
+                      "isLValue": false,
+                      "isPure": false,
+                      "lValueRequested": false,
+                      "memberName": "push",
+                      "nodeType": "MemberAccess",
+                      "referencedDeclaration": null,
+                      "src": "29765:21:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_function_arraypush_nonpayable$_t_uint256_$returns$_t_uint256_$",
+                        "typeString": "function (uint256) returns (uint256)"
+                      }
+                    },
+                    "id": 1173,
+                    "isConstant": false,
+                    "isLValue": false,
+                    "isPure": false,
+                    "kind": "functionCall",
+                    "lValueRequested": false,
+                    "names": [],
+                    "nodeType": "FunctionCall",
+                    "src": "29765:30:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_uint256",
+                      "typeString": "uint256"
+                    }
+                  },
+                  "id": 1174,
+                  "nodeType": "ExpressionStatement",
+                  "src": "29765:30:1"
+                }
+              ]
+            },
+            "documentation": "@dev Private function to add a token to this extension's ownership-tracking data structures.\n@param to address representing the new owner of the given token ID\n@param tokenId uint256 ID of the token to be added to the tokens list of the given address",
+            "id": 1176,
+            "implemented": true,
+            "kind": "function",
+            "modifiers": [],
+            "name": "_addTokenToOwnerEnumeration",
+            "nodeType": "FunctionDefinition",
+            "parameters": {
+              "id": 1157,
+              "nodeType": "ParameterList",
+              "parameters": [
+                {
+                  "constant": false,
+                  "id": 1154,
+                  "name": "to",
+                  "nodeType": "VariableDeclaration",
+                  "scope": 1176,
+                  "src": "29656:10:1",
+                  "stateVariable": false,
+                  "storageLocation": "default",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_address",
+                    "typeString": "address"
+                  },
+                  "typeName": {
+                    "id": 1153,
+                    "name": "address",
+                    "nodeType": "ElementaryTypeName",
+                    "src": "29656:7:1",
+                    "stateMutability": "nonpayable",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_address",
+                      "typeString": "address"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                },
+                {
+                  "constant": false,
+                  "id": 1156,
+                  "name": "tokenId",
+                  "nodeType": "VariableDeclaration",
+                  "scope": 1176,
+                  "src": "29668:15:1",
+                  "stateVariable": false,
+                  "storageLocation": "default",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_uint256",
+                    "typeString": "uint256"
+                  },
+                  "typeName": {
+                    "id": 1155,
+                    "name": "uint256",
+                    "nodeType": "ElementaryTypeName",
+                    "src": "29668:7:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_uint256",
+                      "typeString": "uint256"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                }
+              ],
+              "src": "29655:29:1"
+            },
+            "returnParameters": {
+              "id": 1158,
+              "nodeType": "ParameterList",
+              "parameters": [],
+              "src": "29693:0:1"
+            },
+            "scope": 1302,
+            "src": "29619:183:1",
+            "stateMutability": "nonpayable",
+            "superFunction": null,
+            "visibility": "private"
+          },
+          {
+            "body": {
+              "id": 1194,
+              "nodeType": "Block",
+              "src": "30063:95:1",
+              "statements": [
+                {
+                  "expression": {
+                    "argumentTypes": null,
+                    "id": 1186,
+                    "isConstant": false,
+                    "isLValue": false,
+                    "isPure": false,
+                    "lValueRequested": false,
+                    "leftHandSide": {
+                      "argumentTypes": null,
+                      "baseExpression": {
+                        "argumentTypes": null,
+                        "id": 1181,
+                        "name": "_allTokensIndex",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 992,
+                        "src": "30073:15:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_mapping$_t_uint256_$_t_uint256_$",
+                          "typeString": "mapping(uint256 => uint256)"
+                        }
+                      },
+                      "id": 1183,
+                      "indexExpression": {
+                        "argumentTypes": null,
+                        "id": 1182,
+                        "name": "tokenId",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 1178,
+                        "src": "30089:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      },
+                      "isConstant": false,
+                      "isLValue": true,
+                      "isPure": false,
+                      "lValueRequested": true,
+                      "nodeType": "IndexAccess",
+                      "src": "30073:24:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_uint256",
+                        "typeString": "uint256"
+                      }
+                    },
+                    "nodeType": "Assignment",
+                    "operator": "=",
+                    "rightHandSide": {
+                      "argumentTypes": null,
+                      "expression": {
+                        "argumentTypes": null,
+                        "id": 1184,
+                        "name": "_allTokens",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 988,
+                        "src": "30100:10:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_array$_t_uint256_$dyn_storage",
+                          "typeString": "uint256[] storage ref"
+                        }
+                      },
+                      "id": 1185,
+                      "isConstant": false,
+                      "isLValue": true,
+                      "isPure": false,
+                      "lValueRequested": false,
+                      "memberName": "length",
+                      "nodeType": "MemberAccess",
+                      "referencedDeclaration": null,
+                      "src": "30100:17:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_uint256",
+                        "typeString": "uint256"
+                      }
+                    },
+                    "src": "30073:44:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_uint256",
+                      "typeString": "uint256"
+                    }
+                  },
+                  "id": 1187,
+                  "nodeType": "ExpressionStatement",
+                  "src": "30073:44:1"
+                },
+                {
+                  "expression": {
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+                    "arguments": [
+                      {
+                        "argumentTypes": null,
+                        "id": 1191,
+                        "name": "tokenId",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 1178,
+                        "src": "30143:7:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      }
+                    ],
+                    "expression": {
+                      "argumentTypes": [
+                        {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
+                      ],
+                      "expression": {
+                        "argumentTypes": null,
+                        "id": 1188,
+                        "name": "_allTokens",
+                        "nodeType": "Identifier",
+                        "overloadedDeclarations": [],
+                        "referencedDeclaration": 988,
+                        "src": "30127:10:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_array$_t_uint256_$dyn_storage",
+                          "typeString": "uint256[] storage ref"
+                        }
+                      },
+                      "id": 1190,
+                      "isConstant": false,
+                      "isLValue": false,
+                      "isPure": false,
+                      "lValueRequested": false,
+                      "memberName": "push",
+                      "nodeType": "MemberAccess",
+                      "referencedDeclaration": null,
+                      "src": "30127:15:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_function_arraypush_nonpayable$_t_uint256_$returns$_t_uint256_$",
+                        "typeString": "function (uint256) returns (uint256)"
+                      }
+                    },
+                    "id": 1192,
+                    "isConstant": false,
+                    "isLValue": false,
+                    "isPure": false,
+                    "kind": "functionCall",
+                    "lValueRequested": false,
+                    "names": [],
+                    "nodeType": "FunctionCall",
+                    "src": "30127:24:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_uint256",
+                      "typeString": "uint256"
+                    }
+                  },
+                  "id": 1193,
+                  "nodeType": "ExpressionStatement",
+                  "src": "30127:24:1"
+                }
+              ]
+            },
+            "documentation": "@dev Private function to add a token to this extension's token tracking data structures.\n@param tokenId uint256 ID of the token to be added to the tokens list",
+            "id": 1195,
+            "implemented": true,
+            "kind": "function",
+            "modifiers": [],
+            "name": "_addTokenToAllTokensEnumeration",
+            "nodeType": "FunctionDefinition",
+            "parameters": {
+              "id": 1179,
+              "nodeType": "ParameterList",
+              "parameters": [
+                {
+                  "constant": false,
+                  "id": 1178,
+                  "name": "tokenId",
+                  "nodeType": "VariableDeclaration",
+                  "scope": 1195,
+                  "src": "30038:15:1",
+                  "stateVariable": false,
+                  "storageLocation": "default",
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+                        },
+                        "value": "1"
+                      }
+                    ],
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+                            "src": "31060:12:1",
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+                              "typeIdentifier": "t_mapping$_t_address_$_t_array$_t_uint256_$dyn_storage_$",
+                              "typeString": "mapping(address => uint256[] storage ref)"
+                            }
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+                              "typeIdentifier": "t_address",
+                              "typeString": "address"
+                            }
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+                        "typeString": "function (uint256,uint256) pure returns (uint256)"
+                      }
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+                    "src": "31060:32:1",
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+                      "typeIdentifier": "t_uint256",
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+                    }
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+                },
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+                        "typeIdentifier": "t_uint256",
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+                      },
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+                        "name": "uint256",
+                        "nodeType": "ElementaryTypeName",
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+                        "typeDescriptions": {
+                          "typeIdentifier": "t_uint256",
+                          "typeString": "uint256"
+                        }
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+                        "typeIdentifier": "t_mapping$_t_uint256_$_t_uint256_$",
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+                      }
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+                        "typeString": "uint256"
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+                      "typeString": "uint256"
+                    }
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+                },
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+                      "src": "31253:10:1",
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+                        "typeIdentifier": "t_uint256",
+                        "typeString": "uint256"
+                      }
+                    },
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+                      "name": "lastTokenIndex",
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+                      "src": "31267:14:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_uint256",
+                        "typeString": "uint256"
+                      }
+                    },
+                    "src": "31253:28:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_bool",
+                      "typeString": "bool"
+                    }
+                  },
+                  "falseBody": null,
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+                  "src": "31249:323:1",
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+                    "statements": [
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+                        "assignments": [
+                          1222
+                        ],
+                        "declarations": [
+                          {
+                            "constant": false,
+                            "id": 1222,
+                            "name": "lastTokenId",
+                            "nodeType": "VariableDeclaration",
+                            "scope": 1243,
+                            "src": "31297:19:1",
+                            "stateVariable": false,
+                            "storageLocation": "default",
+                            "typeDescriptions": {
+                              "typeIdentifier": "t_uint256",
+                              "typeString": "uint256"
+                            },
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+                              "name": "uint256",
+                              "nodeType": "ElementaryTypeName",
+                              "src": "31297:7:1",
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+                                "typeIdentifier": "t_uint256",
+                                "typeString": "uint256"
+                              }
+                            },
+                            "value": null,
+                            "visibility": "internal"
+                          }
+                        ],
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+                          "baseExpression": {
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+                              "id": 1223,
+                              "name": "_ownedTokens",
+                              "nodeType": "Identifier",
+                              "overloadedDeclarations": [],
+                              "referencedDeclaration": 981,
+                              "src": "31319:12:1",
+                              "typeDescriptions": {
+                                "typeIdentifier": "t_mapping$_t_address_$_t_array$_t_uint256_$dyn_storage_$",
+                                "typeString": "mapping(address => uint256[] storage ref)"
+                              }
+                            },
+                            "id": 1225,
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+                              "name": "from",
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+                              "referencedDeclaration": 1197,
+                              "src": "31332:4:1",
+                              "typeDescriptions": {
+                                "typeIdentifier": "t_address",
+                                "typeString": "address"
+                              }
+                            },
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+                            "nodeType": "IndexAccess",
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+                              "typeIdentifier": "t_array$_t_uint256_$dyn_storage",
+                              "typeString": "uint256[] storage ref"
+                            }
+                          },
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+                            "argumentTypes": null,
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+                            "name": "lastTokenIndex",
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+                            "src": "31338:14:1",
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+                              "typeIdentifier": "t_uint256",
+                              "typeString": "uint256"
+                            }
+                          },
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+                            "typeIdentifier": "t_uint256",
+                            "typeString": "uint256"
+                          }
+                        },
+                        "nodeType": "VariableDeclarationStatement",
+                        "src": "31297:56:1"
+                      },
+                      {
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+                              "baseExpression": {
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+                                "name": "_ownedTokens",
+                                "nodeType": "Identifier",
+                                "overloadedDeclarations": [],
+                                "referencedDeclaration": 981,
+                                "src": "31368:12:1",
+                                "typeDescriptions": {
+                                  "typeIdentifier": "t_mapping$_t_address_$_t_array$_t_uint256_$dyn_storage_$",
+                                  "typeString": "mapping(address => uint256[] storage ref)"
+                                }
+                              },
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+                                "argumentTypes": null,
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+                                "name": "from",
+                                "nodeType": "Identifier",
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+                                "referencedDeclaration": 1197,
+                                "src": "31381:4:1",
+                                "typeDescriptions": {
+                                  "typeIdentifier": "t_address",
+                                  "typeString": "address"
+                                }
+                              },
+                              "isConstant": false,
+                              "isLValue": true,
+                              "isPure": false,
+                              "lValueRequested": false,
+                              "nodeType": "IndexAccess",
+                              "src": "31368:18:1",
+                              "typeDescriptions": {
+                                "typeIdentifier": "t_array$_t_uint256_$dyn_storage",
+                                "typeString": "uint256[] storage ref"
+                              }
+                            },
+                            "id": 1233,
+                            "indexExpression": {
+                              "argumentTypes": null,
+                              "id": 1231,
+                              "name": "tokenIndex",
+                              "nodeType": "Identifier",
+                              "overloadedDeclarations": [],
+                              "referencedDeclaration": 1213,
+                              "src": "31387:10:1",
+                              "typeDescriptions": {
+                                "typeIdentifier": "t_uint256",
+                                "typeString": "uint256"
+                              }
+                            },
+                            "isConstant": false,
+                            "isLValue": true,
+                            "isPure": false,
+                            "lValueRequested": true,
+                            "nodeType": "IndexAccess",
+                            "src": "31368:30:1",
+                            "typeDescriptions": {
+                              "typeIdentifier": "t_uint256",
+                              "typeString": "uint256"
+                            }
+                          },
+                          "nodeType": "Assignment",
+                          "operator": "=",
+                          "rightHandSide": {
+                            "argumentTypes": null,
+                            "id": 1234,
+                            "name": "lastTokenId",
+                            "nodeType": "Identifier",
+                            "overloadedDeclarations": [],
+                            "referencedDeclaration": 1222,
+                            "src": "31401:11:1",
+                            "typeDescriptions": {
+                              "typeIdentifier": "t_uint256",
+                              "typeString": "uint256"
+                            }
+                          },
+                          "src": "31368:44:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_uint256",
+                            "typeString": "uint256"
+                          }
+                        },
+                        "id": 1236,
+                        "nodeType": "ExpressionStatement",
+                        "src": "31368:44:1"
+                      },
+                      {
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+                          "id": 1241,
+                          "isConstant": false,
+                          "isLValue": false,
+                          "isPure": false,
+                          "lValueRequested": false,
+                          "leftHandSide": {
+                            "argumentTypes": null,
+                            "baseExpression": {
+                              "argumentTypes": null,
+                              "id": 1237,
+                              "name": "_ownedTokensIndex",
+                              "nodeType": "Identifier",
+                              "overloadedDeclarations": [],
+                              "referencedDeclaration": 985,
+                              "src": "31484:17:1",
+                              "typeDescriptions": {
+                                "typeIdentifier": "t_mapping$_t_uint256_$_t_uint256_$",
+                                "typeString": "mapping(uint256 => uint256)"
+                              }
+                            },
+                            "id": 1239,
+                            "indexExpression": {
+                              "argumentTypes": null,
+                              "id": 1238,
+                              "name": "lastTokenId",
+                              "nodeType": "Identifier",
+                              "overloadedDeclarations": [],
+                              "referencedDeclaration": 1222,
+                              "src": "31502:11:1",
+                              "typeDescriptions": {
+                                "typeIdentifier": "t_uint256",
+                                "typeString": "uint256"
+                              }
+                            },
+                            "isConstant": false,
+                            "isLValue": true,
+                            "isPure": false,
+                            "lValueRequested": true,
+                            "nodeType": "IndexAccess",
+                            "src": "31484:30:1",
+                            "typeDescriptions": {
+                              "typeIdentifier": "t_uint256",
+                              "typeString": "uint256"
+                            }
+                          },
+                          "nodeType": "Assignment",
+                          "operator": "=",
+                          "rightHandSide": {
+                            "argumentTypes": null,
+                            "id": 1240,
+                            "name": "tokenIndex",
+                            "nodeType": "Identifier",
+                            "overloadedDeclarations": [],
+                            "referencedDeclaration": 1213,
+                            "src": "31517:10:1",
+                            "typeDescriptions": {
+                              "typeIdentifier": "t_uint256",
+                              "typeString": "uint256"
+                            }
+                          },
+                          "src": "31484:43:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_uint256",
+                            "typeString": "uint256"
+                          }
+                        },
+                        "id": 1242,
+                        "nodeType": "ExpressionStatement",
+                        "src": "31484:43:1"
+                      }
+                    ]
+                  }
+                },
+                {
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+                    "id": 1249,
+                    "isConstant": false,
+                    "isLValue": false,
+                    "isPure": false,
+                    "lValueRequested": false,
+                    "nodeType": "UnaryOperation",
+                    "operator": "--",
+                    "prefix": false,
+                    "src": "31658:27:1",
+                    "subExpression": {
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+                      "expression": {
+                        "argumentTypes": null,
+                        "baseExpression": {
+                          "argumentTypes": null,
+                          "id": 1245,
+                          "name": "_ownedTokens",
+                          "nodeType": "Identifier",
+                          "overloadedDeclarations": [],
+                          "referencedDeclaration": 981,
+                          "src": "31658:12:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_mapping$_t_address_$_t_array$_t_uint256_$dyn_storage_$",
+                            "typeString": "mapping(address => uint256[] storage ref)"
+                          }
+                        },
+                        "id": 1247,
+                        "indexExpression": {
+                          "argumentTypes": null,
+                          "id": 1246,
+                          "name": "from",
+                          "nodeType": "Identifier",
+                          "overloadedDeclarations": [],
+                          "referencedDeclaration": 1197,
+                          "src": "31671:4:1",
+                          "typeDescriptions": {
+                            "typeIdentifier": "t_address",
+                            "typeString": "address"
+                          }
+                        },
+                        "isConstant": false,
+                        "isLValue": true,
+                        "isPure": false,
+                        "lValueRequested": false,
+                        "nodeType": "IndexAccess",
+                        "src": "31658:18:1",
+                        "typeDescriptions": {
+                          "typeIdentifier": "t_array$_t_uint256_$dyn_storage",
+                          "typeString": "uint256[] storage ref"
+                        }
+                      },
+                      "id": 1248,
+                      "isConstant": false,
+                      "isLValue": true,
+                      "isPure": false,
+                      "lValueRequested": true,
+                      "memberName": "length",
+                      "nodeType": "MemberAccess",
+                      "referencedDeclaration": null,
+                      "src": "31658:25:1",
+                      "typeDescriptions": {
+                        "typeIdentifier": "t_uint256",
+                        "typeString": "uint256"
+                      }
+                    },
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_uint256",
+                      "typeString": "uint256"
+                    }
+                  },
+                  "id": 1250,
+                  "nodeType": "ExpressionStatement",
+                  "src": "31658:27:1"
+                }
+              ]
+            },
+            "documentation": "@dev Private function to remove a token from this extension's ownership-tracking data structures. Note that\nwhile the token is not assigned a new owner, the _ownedTokensIndex mapping is _not_ updated: this allows for\ngas optimizations e.g. when performing a transfer operation (avoiding double writes).\nThis has O(1) time complexity, but alters the order of the _ownedTokens array.\n@param from address representing the previous owner of the given token ID\n@param tokenId uint256 ID of the token to be removed from the tokens list of the given address",
+            "id": 1252,
+            "implemented": true,
+            "kind": "function",
+            "modifiers": [],
+            "name": "_removeTokenFromOwnerEnumeration",
+            "nodeType": "FunctionDefinition",
+            "parameters": {
+              "id": 1200,
+              "nodeType": "ParameterList",
+              "parameters": [
+                {
+                  "constant": false,
+                  "id": 1197,
+                  "name": "from",
+                  "nodeType": "VariableDeclaration",
+                  "scope": 1252,
+                  "src": "30815:12:1",
+                  "stateVariable": false,
+                  "storageLocation": "default",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_address",
+                    "typeString": "address"
+                  },
+                  "typeName": {
+                    "id": 1196,
+                    "name": "address",
+                    "nodeType": "ElementaryTypeName",
+                    "src": "30815:7:1",
+                    "stateMutability": "nonpayable",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_address",
+                      "typeString": "address"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                },
+                {
+                  "constant": false,
+                  "id": 1199,
+                  "name": "tokenId",
+                  "nodeType": "VariableDeclaration",
+                  "scope": 1252,
+                  "src": "30829:15:1",
+                  "stateVariable": false,
+                  "storageLocation": "default",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_uint256",
+                    "typeString": "uint256"
+                  },
+                  "typeName": {
+                    "id": 1198,
+                    "name": "uint256",
+                    "nodeType": "ElementaryTypeName",
+                    "src": "30829:7:1",
+                    "typeDescriptions": {
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+              ]
+            },
+            "documentation": "@dev Internal function to burn a specific token.\nReverts if the token does not exist.\nDeprecated, use _burn(uint256) instead.\n@param owner owner of the token to burn\n@param tokenId uint256 ID of the token being burned by the msg.sender",
+            "id": 1447,
+            "implemented": true,
+            "kind": "function",
+            "modifiers": [],
+            "name": "_burn",
+            "nodeType": "FunctionDefinition",
+            "parameters": {
+              "id": 1422,
+              "nodeType": "ParameterList",
+              "parameters": [
+                {
+                  "constant": false,
+                  "id": 1419,
+                  "name": "owner",
+                  "nodeType": "VariableDeclaration",
+                  "scope": 1447,
+                  "src": "36227:13:1",
+                  "stateVariable": false,
+                  "storageLocation": "default",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_address",
+                    "typeString": "address"
+                  },
+                  "typeName": {
+                    "id": 1418,
+                    "name": "address",
+                    "nodeType": "ElementaryTypeName",
+                    "src": "36227:7:1",
+                    "stateMutability": "nonpayable",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_address",
+                      "typeString": "address"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                },
+                {
+                  "constant": false,
+                  "id": 1421,
+                  "name": "tokenId",
+                  "nodeType": "VariableDeclaration",
+                  "scope": 1447,
+                  "src": "36242:15:1",
+                  "stateVariable": false,
+                  "storageLocation": "default",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_uint256",
+                    "typeString": "uint256"
+                  },
+                  "typeName": {
+                    "id": 1420,
+                    "name": "uint256",
+                    "nodeType": "ElementaryTypeName",
+                    "src": "36242:7:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_uint256",
+                      "typeString": "uint256"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                }
+              ],
+              "src": "36226:32:1"
+            },
+            "returnParameters": {
+              "id": 1423,
+              "nodeType": "ParameterList",
+              "parameters": [],
+              "src": "36268:0:1"
+            },
+            "scope": 1448,
+            "src": "36212:240:1",
+            "stateMutability": "nonpayable",
+            "superFunction": 811,
+            "visibility": "internal"
+          }
+        ],
+        "scope": 1469,
+        "src": "33817:2637:1"
+      },
+      {
+        "id": 1449,
+        "literals": [
+          "solidity",
+          "^",
+          "0.5",
+          ".0"
+        ],
+        "nodeType": "PragmaDirective",
+        "src": "36518:23:1"
+      },
+      {
+        "baseContracts": [
+          {
+            "arguments": null,
+            "baseName": {
+              "contractScope": null,
+              "id": 1450,
+              "name": "ERC721",
+              "nodeType": "UserDefinedTypeName",
+              "referencedDeclaration": 944,
+              "src": "36838:6:1",
+              "typeDescriptions": {
+                "typeIdentifier": "t_contract$_ERC721_$944",
+                "typeString": "contract ERC721"
+              }
+            },
+            "id": 1451,
+            "nodeType": "InheritanceSpecifier",
+            "src": "36838:6:1"
+          },
+          {
+            "arguments": null,
+            "baseName": {
+              "contractScope": null,
+              "id": 1452,
+              "name": "ERC721Enumerable",
+              "nodeType": "UserDefinedTypeName",
+              "referencedDeclaration": 1302,
+              "src": "36846:16:1",
+              "typeDescriptions": {
+                "typeIdentifier": "t_contract$_ERC721Enumerable_$1302",
+                "typeString": "contract ERC721Enumerable"
+              }
+            },
+            "id": 1453,
+            "nodeType": "InheritanceSpecifier",
+            "src": "36846:16:1"
+          },
+          {
+            "arguments": null,
+            "baseName": {
+              "contractScope": null,
+              "id": 1454,
+              "name": "ERC721Metadata",
+              "nodeType": "UserDefinedTypeName",
+              "referencedDeclaration": 1448,
+              "src": "36864:14:1",
+              "typeDescriptions": {
+                "typeIdentifier": "t_contract$_ERC721Metadata_$1448",
+                "typeString": "contract ERC721Metadata"
+              }
+            },
+            "id": 1455,
+            "nodeType": "InheritanceSpecifier",
+            "src": "36864:14:1"
+          }
+        ],
+        "contractDependencies": [
+          944,
+          969,
+          23,
+          124,
+          386,
+          1302,
+          1323,
+          1448
+        ],
+        "contractKind": "contract",
+        "documentation": "@title Full ERC721 Token\nThis implementation includes all the required and some optional functionality of the ERC721 standard\nMoreover, it includes approve all functionality using operator terminology\n@dev see https://eips.ethereum.org/EIPS/eip-721",
+        "fullyImplemented": true,
+        "id": 1468,
+        "linearizedBaseContracts": [
+          1468,
+          1448,
+          1323,
+          1302,
+          969,
+          944,
+          124,
+          386,
+          23
+        ],
+        "name": "ERC721Full",
+        "nodeType": "ContractDefinition",
+        "nodes": [
+          {
+            "body": {
+              "id": 1466,
+              "nodeType": "Block",
+              "src": "36976:64:1",
+              "statements": []
+            },
+            "documentation": null,
+            "id": 1467,
+            "implemented": true,
+            "kind": "constructor",
+            "modifiers": [
+              {
+                "arguments": [
+                  {
+                    "argumentTypes": null,
+                    "id": 1462,
+                    "name": "name",
+                    "nodeType": "Identifier",
+                    "overloadedDeclarations": [],
+                    "referencedDeclaration": 1457,
+                    "src": "36962:4:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_string_memory_ptr",
+                      "typeString": "string memory"
+                    }
+                  },
+                  {
+                    "argumentTypes": null,
+                    "id": 1463,
+                    "name": "symbol",
+                    "nodeType": "Identifier",
+                    "overloadedDeclarations": [],
+                    "referencedDeclaration": 1459,
+                    "src": "36968:6:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_string_memory_ptr",
+                      "typeString": "string memory"
+                    }
+                  }
+                ],
+                "id": 1464,
+                "modifierName": {
+                  "argumentTypes": null,
+                  "id": 1461,
+                  "name": "ERC721Metadata",
+                  "nodeType": "Identifier",
+                  "overloadedDeclarations": [],
+                  "referencedDeclaration": 1448,
+                  "src": "36947:14:1",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_type$_t_contract$_ERC721Metadata_$1448_$",
+                    "typeString": "type(contract ERC721Metadata)"
+                  }
+                },
+                "nodeType": "ModifierInvocation",
+                "src": "36947:28:1"
+              }
+            ],
+            "name": "",
+            "nodeType": "FunctionDefinition",
+            "parameters": {
+              "id": 1460,
+              "nodeType": "ParameterList",
+              "parameters": [
+                {
+                  "constant": false,
+                  "id": 1457,
+                  "name": "name",
+                  "nodeType": "VariableDeclaration",
+                  "scope": 1467,
+                  "src": "36898:18:1",
+                  "stateVariable": false,
+                  "storageLocation": "memory",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_string_memory_ptr",
+                    "typeString": "string"
+                  },
+                  "typeName": {
+                    "id": 1456,
+                    "name": "string",
+                    "nodeType": "ElementaryTypeName",
+                    "src": "36898:6:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_string_storage_ptr",
+                      "typeString": "string"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                },
+                {
+                  "constant": false,
+                  "id": 1459,
+                  "name": "symbol",
+                  "nodeType": "VariableDeclaration",
+                  "scope": 1467,
+                  "src": "36918:20:1",
+                  "stateVariable": false,
+                  "storageLocation": "memory",
+                  "typeDescriptions": {
+                    "typeIdentifier": "t_string_memory_ptr",
+                    "typeString": "string"
+                  },
+                  "typeName": {
+                    "id": 1458,
+                    "name": "string",
+                    "nodeType": "ElementaryTypeName",
+                    "src": "36918:6:1",
+                    "typeDescriptions": {
+                      "typeIdentifier": "t_string_storage_ptr",
+                      "typeString": "string"
+                    }
+                  },
+                  "value": null,
+                  "visibility": "internal"
+                }
+              ],
+              "src": "36897:42:1"
+            },
+            "returnParameters": {
+              "id": 1465,
+              "nodeType": "ParameterList",
+              "parameters": [],
+              "src": "36976:0:1"
+            },
+            "scope": 1468,
+            "src": "36885:155:1",
+            "stateMutability": "nonpayable",
+            "superFunction": null,
+            "visibility": "public"
+          }
+        ],
+        "scope": 1469,
+        "src": "36815:227:1"
+      }
+    ],
+    "src": "61:36982:1"
+  },
+  "compiler": {
+    "name": "solc",
+    "version": "0.5.0+commit.1d4f565a.Emscripten.clang"
+  },
+  "networks": {},
+  "schemaVersion": "3.0.2",
+  "updatedAt": "2019-09-05T15:01:09.135Z",
+  "devdoc": {
+    "details": "Wrappers over Solidity's arithmetic operations with added overflow checks. * Arithmetic operations in Solidity wrap on overflow. This can easily result in bugs, because programmers usually assume that an overflow raises an error, which is the standard behavior in high level programming languages. `SafeMath` restores this intuition by reverting the transaction when an operation overflows. * Using this library instead of the unchecked operations eliminates an entire class of bugs, so it's recommended to use it always.",
+    "methods": {}
+  },
+  "userdoc": {
+    "methods": {}
+  }
+}
\ No newline at end of file
diff --git a/src/components/App.css b/src/components/App.css
index 87b6089..2a9a4e6 100644
--- a/src/components/App.css
+++ b/src/components/App.css
@@ -1 +1,8 @@
 /* Styles go here */
+
+.token {
+  height: 150px;
+  width: 150px;
+  border-radius: 50%;
+  display: inline-block;
+}
diff --git a/src/components/App.js b/src/components/App.js
index 588f625..02383db 100755
--- a/src/components/App.js
+++ b/src/components/App.js
@@ -1,8 +1,74 @@
 import React, { Component } from 'react';
-import logo from '../logo.png';
+import Web3 from 'web3'
 import './App.css';
+import Color from '../abis/Color.json'
 
 class App extends Component {
+
+  async componentWillMount() {
+    await this.loadWeb3()
+    await this.loadBlockchainData()
+  }
+
+  async loadWeb3() {
+    if (window.ethereum) {
+      window.web3 = new Web3(window.ethereum)
+      await window.ethereum.enable()
+    }
+    else if (window.web3) {
+      window.web3 = new Web3(window.web3.currentProvider)
+    }
+    else {
+      window.alert('Non-Ethereum browser detected. You should consider trying MetaMask!')
+    }
+  }
+
+  async loadBlockchainData() {
+    const web3 = window.web3
+    // Load account
+    const accounts = await web3.eth.getAccounts()
+    this.setState({ account: accounts[0] })
+
+    const networkId = await web3.eth.net.getId()
+    const networkData = Color.networks[networkId]
+    if(networkData) {
+      const abi = Color.abi
+      const address = networkData.address
+      const contract = new web3.eth.Contract(abi, address)
+      this.setState({ contract })
+      const totalSupply = await contract.methods.totalSupply().call()
+      this.setState({ totalSupply })
+      // Load Colors
+      for (var i = 1; i <= totalSupply; i++) {
+        const color = await contract.methods.colors(i - 1).call()
+        this.setState({
+          colors: [...this.state.colors, color]
+        })
+      }
+    } else {
+      window.alert('Smart contract not deployed to detected network.')
+    }
+  }
+
+  mint = (color) => {
+    this.state.contract.methods.mint(color).send({ from: this.state.account })
+    .once('receipt', (receipt) => {
+      this.setState({
+        colors: [...this.state.colors, color]
+      })
+    })
+  }
+
+  constructor(props) {
+    super(props)
+    this.state = {
+      account: '',
+      contract: null,
+      totalSupply: 0,
+      colors: []
+    }
+  }
+
   render() {
     return (
       <div>
@@ -13,35 +79,50 @@ class App extends Component {
             target="_blank"
             rel="noopener noreferrer"
           >
-            Dapp University
+            Color Tokens
           </a>
+          <ul className="navbar-nav px-3">
+            <li className="nav-item text-nowrap d-none d-sm-none d-sm-block">
+              <small className="text-white"><span id="account">{this.state.account}</span></small>
+            </li>
+          </ul>
         </nav>
         <div className="container-fluid mt-5">
           <div className="row">
             <main role="main" className="col-lg-12 d-flex text-center">
               <div className="content mr-auto ml-auto">
-                <a
-                  href="http://www.dappuniversity.com/bootcamp"
-                  target="_blank"
-                  rel="noopener noreferrer"
-                >
-                  <img src={logo} className="App-logo" alt="logo" />
-                </a>
-                <h1>Dapp University Starter Kit</h1>
-                <p>
-                  Edit <code>src/components/App.js</code> and save to reload.
-                </p>
-                <a
-                  className="App-link"
-                  href="http://www.dappuniversity.com/bootcamp"
-                  target="_blank"
-                  rel="noopener noreferrer"
-                >
-                  LEARN BLOCKCHAIN <u><b>NOW! </b></u>
-                </a>
+                <h1>Issue Token</h1>
+                <form onSubmit={(event) => {
+                  event.preventDefault()
+                  const color = this.color.value
+                  this.mint(color)
+                }}>
+                  <input
+                    type='text'
+                    className='form-control mb-1'
+                    placeholder='e.g. #FFFFFF'
+                    ref={(input) => { this.color = input }}
+                  />
+                  <input
+                    type='submit'
+                    className='btn btn-block btn-primary'
+                    value='MINT'
+                  />
+                </form>
               </div>
             </main>
           </div>
+          <hr/>
+          <div className="row text-center">
+            { this.state.colors.map((color, key) => {
+              return(
+                <div key={key} className="col-md-3 mb-3">
+                  <div className="token" style={{ backgroundColor: color }}></div>
+                  <div>{color}</div>
+                </div>
+              )
+            })}
+          </div>
         </div>
       </div>
     );
diff --git a/src/contracts/Color.sol b/src/contracts/Color.sol
new file mode 100644
index 0000000..1d6959c
--- /dev/null
+++ b/src/contracts/Color.sol
@@ -0,0 +1,20 @@
+pragma solidity 0.5.0;
+
+import "./ERC721Full.sol";
+
+contract Color is ERC721Full {
+  string[] public colors;
+  mapping(string => bool) _colorExists;
+
+  constructor() ERC721Full("Color", "COLOR") public {
+  }
+
+  // E.G. color = "#FFFFFF"
+  function mint(string memory _color) public {
+    require(!_colorExists[_color]);
+    uint _id = colors.push(_color);
+    _mint(msg.sender, _id);
+    _colorExists[_color] = true;
+  }
+
+}
diff --git a/src/contracts/ERC721Full.sol b/src/contracts/ERC721Full.sol
new file mode 100644
index 0000000..5ec9734
--- /dev/null
+++ b/src/contracts/ERC721Full.sol
@@ -0,0 +1,984 @@
+
+// File: @openzeppelin/contracts/introspection/IERC165.sol
+
+pragma solidity ^0.5.0;
+
+/**
+ * @dev Interface of the ERC165 standard, as defined in the
+ * [EIP](https://eips.ethereum.org/EIPS/eip-165).
+ *
+ * Implementers can declare support of contract interfaces, which can then be
+ * queried by others (`ERC165Checker`).
+ *
+ * For an implementation, see `ERC165`.
+ */
+interface IERC165 {
+    /**
+     * @dev Returns true if this contract implements the interface defined by
+     * `interfaceId`. See the corresponding
+     * [EIP section](https://eips.ethereum.org/EIPS/eip-165#how-interfaces-are-identified)
+     * to learn more about how these ids are created.
+     *
+     * This function call must use less than 30 000 gas.
+     */
+    function supportsInterface(bytes4 interfaceId) external view returns (bool);
+}
+
+// File: @openzeppelin/contracts/token/ERC721/IERC721.sol
+
+pragma solidity ^0.5.0;
+
+
+/**
+ * @dev Required interface of an ERC721 compliant contract.
+ */
+contract IERC721 is IERC165 {
+    event Transfer(address indexed from, address indexed to, uint256 indexed tokenId);
+    event Approval(address indexed owner, address indexed approved, uint256 indexed tokenId);
+    event ApprovalForAll(address indexed owner, address indexed operator, bool approved);
+
+    /**
+     * @dev Returns the number of NFTs in `owner`'s account.
+     */
+    function balanceOf(address owner) public view returns (uint256 balance);
+
+    /**
+     * @dev Returns the owner of the NFT specified by `tokenId`.
+     */
+    function ownerOf(uint256 tokenId) public view returns (address owner);
+
+    /**
+     * @dev Transfers a specific NFT (`tokenId`) from one account (`from`) to
+     * another (`to`).
+     *
+     * 
+     *
+     * Requirements:
+     * - `from`, `to` cannot be zero.
+     * - `tokenId` must be owned by `from`.
+     * - If the caller is not `from`, it must be have been allowed to move this
+     * NFT by either `approve` or `setApproveForAll`.
+     */
+    function safeTransferFrom(address from, address to, uint256 tokenId) public;
+    /**
+     * @dev Transfers a specific NFT (`tokenId`) from one account (`from`) to
+     * another (`to`).
+     *
+     * Requirements:
+     * - If the caller is not `from`, it must be approved to move this NFT by
+     * either `approve` or `setApproveForAll`.
+     */
+    function transferFrom(address from, address to, uint256 tokenId) public;
+    function approve(address to, uint256 tokenId) public;
+    function getApproved(uint256 tokenId) public view returns (address operator);
+
+    function setApprovalForAll(address operator, bool _approved) public;
+    function isApprovedForAll(address owner, address operator) public view returns (bool);
+
+
+    function safeTransferFrom(address from, address to, uint256 tokenId, bytes memory data) public;
+}
+
+// File: @openzeppelin/contracts/token/ERC721/IERC721Receiver.sol
+
+pragma solidity ^0.5.0;
+
+/**
+ * @title ERC721 token receiver interface
+ * @dev Interface for any contract that wants to support safeTransfers
+ * from ERC721 asset contracts.
+ */
+contract IERC721Receiver {
+    /**
+     * @notice Handle the receipt of an NFT
+     * @dev The ERC721 smart contract calls this function on the recipient
+     * after a `safeTransfer`. This function MUST return the function selector,
+     * otherwise the caller will revert the transaction. The selector to be
+     * returned can be obtained as `this.onERC721Received.selector`. This
+     * function MAY throw to revert and reject the transfer.
+     * Note: the ERC721 contract address is always the message sender.
+     * @param operator The address which called `safeTransferFrom` function
+     * @param from The address which previously owned the token
+     * @param tokenId The NFT identifier which is being transferred
+     * @param data Additional data with no specified format
+     * @return bytes4 `bytes4(keccak256("onERC721Received(address,address,uint256,bytes)"))`
+     */
+    function onERC721Received(address operator, address from, uint256 tokenId, bytes memory data)
+    public returns (bytes4);
+}
+
+// File: @openzeppelin/contracts/math/SafeMath.sol
+
+pragma solidity ^0.5.0;
+
+/**
+ * @dev Wrappers over Solidity's arithmetic operations with added overflow
+ * checks.
+ *
+ * Arithmetic operations in Solidity wrap on overflow. This can easily result
+ * in bugs, because programmers usually assume that an overflow raises an
+ * error, which is the standard behavior in high level programming languages.
+ * `SafeMath` restores this intuition by reverting the transaction when an
+ * operation overflows.
+ *
+ * Using this library instead of the unchecked operations eliminates an entire
+ * class of bugs, so it's recommended to use it always.
+ */
+library SafeMath {
+    /**
+     * @dev Returns the addition of two unsigned integers, reverting on
+     * overflow.
+     *
+     * Counterpart to Solidity's `+` operator.
+     *
+     * Requirements:
+     * - Addition cannot overflow.
+     */
+    function add(uint256 a, uint256 b) internal pure returns (uint256) {
+        uint256 c = a + b;
+        require(c >= a, "SafeMath: addition overflow");
+
+        return c;
+    }
+
+    /**
+     * @dev Returns the subtraction of two unsigned integers, reverting on
+     * overflow (when the result is negative).
+     *
+     * Counterpart to Solidity's `-` operator.
+     *
+     * Requirements:
+     * - Subtraction cannot overflow.
+     */
+    function sub(uint256 a, uint256 b) internal pure returns (uint256) {
+        require(b <= a, "SafeMath: subtraction overflow");
+        uint256 c = a - b;
+
+        return c;
+    }
+
+    /**
+     * @dev Returns the multiplication of two unsigned integers, reverting on
+     * overflow.
+     *
+     * Counterpart to Solidity's `*` operator.
+     *
+     * Requirements:
+     * - Multiplication cannot overflow.
+     */
+    function mul(uint256 a, uint256 b) internal pure returns (uint256) {
+        // Gas optimization: this is cheaper than requiring 'a' not being zero, but the
+        // benefit is lost if 'b' is also tested.
+        // See: https://github.com/OpenZeppelin/openzeppelin-contracts/pull/522
+        if (a == 0) {
+            return 0;
+        }
+
+        uint256 c = a * b;
+        require(c / a == b, "SafeMath: multiplication overflow");
+
+        return c;
+    }
+
+    /**
+     * @dev Returns the integer division of two unsigned integers. Reverts on
+     * division by zero. The result is rounded towards zero.
+     *
+     * Counterpart to Solidity's `/` operator. Note: this function uses a
+     * `revert` opcode (which leaves remaining gas untouched) while Solidity
+     * uses an invalid opcode to revert (consuming all remaining gas).
+     *
+     * Requirements:
+     * - The divisor cannot be zero.
+     */
+    function div(uint256 a, uint256 b) internal pure returns (uint256) {
+        // Solidity only automatically asserts when dividing by 0
+        require(b > 0, "SafeMath: division by zero");
+        uint256 c = a / b;
+        // assert(a == b * c + a % b); // There is no case in which this doesn't hold
+
+        return c;
+    }
+
+    /**
+     * @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo),
+     * Reverts when dividing by zero.
+     *
+     * Counterpart to Solidity's `%` operator. This function uses a `revert`
+     * opcode (which leaves remaining gas untouched) while Solidity uses an
+     * invalid opcode to revert (consuming all remaining gas).
+     *
+     * Requirements:
+     * - The divisor cannot be zero.
+     */
+    function mod(uint256 a, uint256 b) internal pure returns (uint256) {
+        require(b != 0, "SafeMath: modulo by zero");
+        return a % b;
+    }
+}
+
+// File: @openzeppelin/contracts/utils/Address.sol
+
+pragma solidity ^0.5.0;
+
+/**
+ * @dev Collection of functions related to the address type,
+ */
+library Address {
+    /**
+     * @dev Returns true if `account` is a contract.
+     *
+     * This test is non-exhaustive, and there may be false-negatives: during the
+     * execution of a contract's constructor, its address will be reported as
+     * not containing a contract.
+     *
+     * > It is unsafe to assume that an address for which this function returns
+     * false is an externally-owned account (EOA) and not a contract.
+     */
+    function isContract(address account) internal view returns (bool) {
+        // This method relies in extcodesize, which returns 0 for contracts in
+        // construction, since the code is only stored at the end of the
+        // constructor execution.
+
+        uint256 size;
+        // solhint-disable-next-line no-inline-assembly
+        assembly { size := extcodesize(account) }
+        return size > 0;
+    }
+}
+
+// File: @openzeppelin/contracts/drafts/Counters.sol
+
+pragma solidity ^0.5.0;
+
+
+/**
+ * @title Counters
+ * @author Matt Condon (@shrugs)
+ * @dev Provides counters that can only be incremented or decremented by one. This can be used e.g. to track the number
+ * of elements in a mapping, issuing ERC721 ids, or counting request ids.
+ *
+ * Include with `using Counters for Counters.Counter;`
+ * Since it is not possible to overflow a 256 bit integer with increments of one, `increment` can skip the SafeMath
+ * overflow check, thereby saving gas. This does assume however correct usage, in that the underlying `_value` is never
+ * directly accessed.
+ */
+library Counters {
+    using SafeMath for uint256;
+
+    struct Counter {
+        // This variable should never be directly accessed by users of the library: interactions must be restricted to
+        // the library's function. As of Solidity v0.5.2, this cannot be enforced, though there is a proposal to add
+        // this feature: see https://github.com/ethereum/solidity/issues/4637
+        uint256 _value; // default: 0
+    }
+
+    function current(Counter storage counter) internal view returns (uint256) {
+        return counter._value;
+    }
+
+    function increment(Counter storage counter) internal {
+        counter._value += 1;
+    }
+
+    function decrement(Counter storage counter) internal {
+        counter._value = counter._value.sub(1);
+    }
+}
+
+// File: @openzeppelin/contracts/introspection/ERC165.sol
+
+pragma solidity ^0.5.0;
+
+
+/**
+ * @dev Implementation of the `IERC165` interface.
+ *
+ * Contracts may inherit from this and call `_registerInterface` to declare
+ * their support of an interface.
+ */
+contract ERC165 is IERC165 {
+    /*
+     * bytes4(keccak256('supportsInterface(bytes4)')) == 0x01ffc9a7
+     */
+    bytes4 private constant _INTERFACE_ID_ERC165 = 0x01ffc9a7;
+
+    /**
+     * @dev Mapping of interface ids to whether or not it's supported.
+     */
+    mapping(bytes4 => bool) private _supportedInterfaces;
+
+    constructor () internal {
+        // Derived contracts need only register support for their own interfaces,
+        // we register support for ERC165 itself here
+        _registerInterface(_INTERFACE_ID_ERC165);
+    }
+
+    /**
+     * @dev See `IERC165.supportsInterface`.
+     *
+     * Time complexity O(1), guaranteed to always use less than 30 000 gas.
+     */
+    function supportsInterface(bytes4 interfaceId) external view returns (bool) {
+        return _supportedInterfaces[interfaceId];
+    }
+
+    /**
+     * @dev Registers the contract as an implementer of the interface defined by
+     * `interfaceId`. Support of the actual ERC165 interface is automatic and
+     * registering its interface id is not required.
+     *
+     * See `IERC165.supportsInterface`.
+     *
+     * Requirements:
+     *
+     * - `interfaceId` cannot be the ERC165 invalid interface (`0xffffffff`).
+     */
+    function _registerInterface(bytes4 interfaceId) internal {
+        require(interfaceId != 0xffffffff, "ERC165: invalid interface id");
+        _supportedInterfaces[interfaceId] = true;
+    }
+}
+
+// File: @openzeppelin/contracts/token/ERC721/ERC721.sol
+
+pragma solidity ^0.5.0;
+
+
+
+
+
+
+
+/**
+ * @title ERC721 Non-Fungible Token Standard basic implementation
+ * @dev see https://eips.ethereum.org/EIPS/eip-721
+ */
+contract ERC721 is ERC165, IERC721 {
+    using SafeMath for uint256;
+    using Address for address;
+    using Counters for Counters.Counter;
+
+    // Equals to `bytes4(keccak256("onERC721Received(address,address,uint256,bytes)"))`
+    // which can be also obtained as `IERC721Receiver(0).onERC721Received.selector`
+    bytes4 private constant _ERC721_RECEIVED = 0x150b7a02;
+
+    // Mapping from token ID to owner
+    mapping (uint256 => address) private _tokenOwner;
+
+    // Mapping from token ID to approved address
+    mapping (uint256 => address) private _tokenApprovals;
+
+    // Mapping from owner to number of owned token
+    mapping (address => Counters.Counter) private _ownedTokensCount;
+
+    // Mapping from owner to operator approvals
+    mapping (address => mapping (address => bool)) private _operatorApprovals;
+
+    /*
+     *     bytes4(keccak256('balanceOf(address)')) == 0x70a08231
+     *     bytes4(keccak256('ownerOf(uint256)')) == 0x6352211e
+     *     bytes4(keccak256('approve(address,uint256)')) == 0x095ea7b3
+     *     bytes4(keccak256('getApproved(uint256)')) == 0x081812fc
+     *     bytes4(keccak256('setApprovalForAll(address,bool)')) == 0xa22cb465
+     *     bytes4(keccak256('isApprovedForAll(address,address)')) == 0xe985e9c
+     *     bytes4(keccak256('transferFrom(address,address,uint256)')) == 0x23b872dd
+     *     bytes4(keccak256('safeTransferFrom(address,address,uint256)')) == 0x42842e0e
+     *     bytes4(keccak256('safeTransferFrom(address,address,uint256,bytes)')) == 0xb88d4fde
+     *
+     *     => 0x70a08231 ^ 0x6352211e ^ 0x095ea7b3 ^ 0x081812fc ^
+     *        0xa22cb465 ^ 0xe985e9c ^ 0x23b872dd ^ 0x42842e0e ^ 0xb88d4fde == 0x80ac58cd
+     */
+    bytes4 private constant _INTERFACE_ID_ERC721 = 0x80ac58cd;
+
+    constructor () public {
+        // register the supported interfaces to conform to ERC721 via ERC165
+        _registerInterface(_INTERFACE_ID_ERC721);
+    }
+
+    /**
+     * @dev Gets the balance of the specified address.
+     * @param owner address to query the balance of
+     * @return uint256 representing the amount owned by the passed address
+     */
+    function balanceOf(address owner) public view returns (uint256) {
+        require(owner != address(0), "ERC721: balance query for the zero address");
+
+        return _ownedTokensCount[owner].current();
+    }
+
+    /**
+     * @dev Gets the owner of the specified token ID.
+     * @param tokenId uint256 ID of the token to query the owner of
+     * @return address currently marked as the owner of the given token ID
+     */
+    function ownerOf(uint256 tokenId) public view returns (address) {
+        address owner = _tokenOwner[tokenId];
+        require(owner != address(0), "ERC721: owner query for nonexistent token");
+
+        return owner;
+    }
+
+    /**
+     * @dev Approves another address to transfer the given token ID
+     * The zero address indicates there is no approved address.
+     * There can only be one approved address per token at a given time.
+     * Can only be called by the token owner or an approved operator.
+     * @param to address to be approved for the given token ID
+     * @param tokenId uint256 ID of the token to be approved
+     */
+    function approve(address to, uint256 tokenId) public {
+        address owner = ownerOf(tokenId);
+        require(to != owner, "ERC721: approval to current owner");
+
+        require(msg.sender == owner || isApprovedForAll(owner, msg.sender),
+            "ERC721: approve caller is not owner nor approved for all"
+        );
+
+        _tokenApprovals[tokenId] = to;
+        emit Approval(owner, to, tokenId);
+    }
+
+    /**
+     * @dev Gets the approved address for a token ID, or zero if no address set
+     * Reverts if the token ID does not exist.
+     * @param tokenId uint256 ID of the token to query the approval of
+     * @return address currently approved for the given token ID
+     */
+    function getApproved(uint256 tokenId) public view returns (address) {
+        require(_exists(tokenId), "ERC721: approved query for nonexistent token");
+
+        return _tokenApprovals[tokenId];
+    }
+
+    /**
+     * @dev Sets or unsets the approval of a given operator
+     * An operator is allowed to transfer all tokens of the sender on their behalf.
+     * @param to operator address to set the approval
+     * @param approved representing the status of the approval to be set
+     */
+    function setApprovalForAll(address to, bool approved) public {
+        require(to != msg.sender, "ERC721: approve to caller");
+
+        _operatorApprovals[msg.sender][to] = approved;
+        emit ApprovalForAll(msg.sender, to, approved);
+    }
+
+    /**
+     * @dev Tells whether an operator is approved by a given owner.
+     * @param owner owner address which you want to query the approval of
+     * @param operator operator address which you want to query the approval of
+     * @return bool whether the given operator is approved by the given owner
+     */
+    function isApprovedForAll(address owner, address operator) public view returns (bool) {
+        return _operatorApprovals[owner][operator];
+    }
+
+    /**
+     * @dev Transfers the ownership of a given token ID to another address.
+     * Usage of this method is discouraged, use `safeTransferFrom` whenever possible.
+     * Requires the msg.sender to be the owner, approved, or operator.
+     * @param from current owner of the token
+     * @param to address to receive the ownership of the given token ID
+     * @param tokenId uint256 ID of the token to be transferred
+     */
+    function transferFrom(address from, address to, uint256 tokenId) public {
+        //solhint-disable-next-line max-line-length
+        require(_isApprovedOrOwner(msg.sender, tokenId), "ERC721: transfer caller is not owner nor approved");
+
+        _transferFrom(from, to, tokenId);
+    }
+
+    /**
+     * @dev Safely transfers the ownership of a given token ID to another address
+     * If the target address is a contract, it must implement `onERC721Received`,
+     * which is called upon a safe transfer, and return the magic value
+     * `bytes4(keccak256("onERC721Received(address,address,uint256,bytes)"))`; otherwise,
+     * the transfer is reverted.
+     * Requires the msg.sender to be the owner, approved, or operator
+     * @param from current owner of the token
+     * @param to address to receive the ownership of the given token ID
+     * @param tokenId uint256 ID of the token to be transferred
+     */
+    function safeTransferFrom(address from, address to, uint256 tokenId) public {
+        safeTransferFrom(from, to, tokenId, "");
+    }
+
+    /**
+     * @dev Safely transfers the ownership of a given token ID to another address
+     * If the target address is a contract, it must implement `onERC721Received`,
+     * which is called upon a safe transfer, and return the magic value
+     * `bytes4(keccak256("onERC721Received(address,address,uint256,bytes)"))`; otherwise,
+     * the transfer is reverted.
+     * Requires the msg.sender to be the owner, approved, or operator
+     * @param from current owner of the token
+     * @param to address to receive the ownership of the given token ID
+     * @param tokenId uint256 ID of the token to be transferred
+     * @param _data bytes data to send along with a safe transfer check
+     */
+    function safeTransferFrom(address from, address to, uint256 tokenId, bytes memory _data) public {
+        transferFrom(from, to, tokenId);
+        require(_checkOnERC721Received(from, to, tokenId, _data), "ERC721: transfer to non ERC721Receiver implementer");
+    }
+
+    /**
+     * @dev Returns whether the specified token exists.
+     * @param tokenId uint256 ID of the token to query the existence of
+     * @return bool whether the token exists
+     */
+    function _exists(uint256 tokenId) internal view returns (bool) {
+        address owner = _tokenOwner[tokenId];
+        return owner != address(0);
+    }
+
+    /**
+     * @dev Returns whether the given spender can transfer a given token ID.
+     * @param spender address of the spender to query
+     * @param tokenId uint256 ID of the token to be transferred
+     * @return bool whether the msg.sender is approved for the given token ID,
+     * is an operator of the owner, or is the owner of the token
+     */
+    function _isApprovedOrOwner(address spender, uint256 tokenId) internal view returns (bool) {
+        require(_exists(tokenId), "ERC721: operator query for nonexistent token");
+        address owner = ownerOf(tokenId);
+        return (spender == owner || getApproved(tokenId) == spender || isApprovedForAll(owner, spender));
+    }
+
+    /**
+     * @dev Internal function to mint a new token.
+     * Reverts if the given token ID already exists.
+     * @param to The address that will own the minted token
+     * @param tokenId uint256 ID of the token to be minted
+     */
+    function _mint(address to, uint256 tokenId) internal {
+        require(to != address(0), "ERC721: mint to the zero address");
+        require(!_exists(tokenId), "ERC721: token already minted");
+
+        _tokenOwner[tokenId] = to;
+        _ownedTokensCount[to].increment();
+
+        emit Transfer(address(0), to, tokenId);
+    }
+
+    /**
+     * @dev Internal function to burn a specific token.
+     * Reverts if the token does not exist.
+     * Deprecated, use _burn(uint256) instead.
+     * @param owner owner of the token to burn
+     * @param tokenId uint256 ID of the token being burned
+     */
+    function _burn(address owner, uint256 tokenId) internal {
+        require(ownerOf(tokenId) == owner, "ERC721: burn of token that is not own");
+
+        _clearApproval(tokenId);
+
+        _ownedTokensCount[owner].decrement();
+        _tokenOwner[tokenId] = address(0);
+
+        emit Transfer(owner, address(0), tokenId);
+    }
+
+    /**
+     * @dev Internal function to burn a specific token.
+     * Reverts if the token does not exist.
+     * @param tokenId uint256 ID of the token being burned
+     */
+    function _burn(uint256 tokenId) internal {
+        _burn(ownerOf(tokenId), tokenId);
+    }
+
+    /**
+     * @dev Internal function to transfer ownership of a given token ID to another address.
+     * As opposed to transferFrom, this imposes no restrictions on msg.sender.
+     * @param from current owner of the token
+     * @param to address to receive the ownership of the given token ID
+     * @param tokenId uint256 ID of the token to be transferred
+     */
+    function _transferFrom(address from, address to, uint256 tokenId) internal {
+        require(ownerOf(tokenId) == from, "ERC721: transfer of token that is not own");
+        require(to != address(0), "ERC721: transfer to the zero address");
+
+        _clearApproval(tokenId);
+
+        _ownedTokensCount[from].decrement();
+        _ownedTokensCount[to].increment();
+
+        _tokenOwner[tokenId] = to;
+
+        emit Transfer(from, to, tokenId);
+    }
+
+    /**
+     * @dev Internal function to invoke `onERC721Received` on a target address.
+     * The call is not executed if the target address is not a contract.
+     *
+     * This function is deprecated.
+     * @param from address representing the previous owner of the given token ID
+     * @param to target address that will receive the tokens
+     * @param tokenId uint256 ID of the token to be transferred
+     * @param _data bytes optional data to send along with the call
+     * @return bool whether the call correctly returned the expected magic value
+     */
+    function _checkOnERC721Received(address from, address to, uint256 tokenId, bytes memory _data)
+        internal returns (bool)
+    {
+        if (!to.isContract()) {
+            return true;
+        }
+
+        bytes4 retval = IERC721Receiver(to).onERC721Received(msg.sender, from, tokenId, _data);
+        return (retval == _ERC721_RECEIVED);
+    }
+
+    /**
+     * @dev Private function to clear current approval of a given token ID.
+     * @param tokenId uint256 ID of the token to be transferred
+     */
+    function _clearApproval(uint256 tokenId) private {
+        if (_tokenApprovals[tokenId] != address(0)) {
+            _tokenApprovals[tokenId] = address(0);
+        }
+    }
+}
+
+// File: @openzeppelin/contracts/token/ERC721/IERC721Enumerable.sol
+
+pragma solidity ^0.5.0;
+
+
+/**
+ * @title ERC-721 Non-Fungible Token Standard, optional enumeration extension
+ * @dev See https://eips.ethereum.org/EIPS/eip-721
+ */
+contract IERC721Enumerable is IERC721 {
+    function totalSupply() public view returns (uint256);
+    function tokenOfOwnerByIndex(address owner, uint256 index) public view returns (uint256 tokenId);
+
+    function tokenByIndex(uint256 index) public view returns (uint256);
+}
+
+// File: @openzeppelin/contracts/token/ERC721/ERC721Enumerable.sol
+
+pragma solidity ^0.5.0;
+
+
+
+
+/**
+ * @title ERC-721 Non-Fungible Token with optional enumeration extension logic
+ * @dev See https://eips.ethereum.org/EIPS/eip-721
+ */
+contract ERC721Enumerable is ERC165, ERC721, IERC721Enumerable {
+    // Mapping from owner to list of owned token IDs
+    mapping(address => uint256[]) private _ownedTokens;
+
+    // Mapping from token ID to index of the owner tokens list
+    mapping(uint256 => uint256) private _ownedTokensIndex;
+
+    // Array with all token ids, used for enumeration
+    uint256[] private _allTokens;
+
+    // Mapping from token id to position in the allTokens array
+    mapping(uint256 => uint256) private _allTokensIndex;
+
+    /*
+     *     bytes4(keccak256('totalSupply()')) == 0x18160ddd
+     *     bytes4(keccak256('tokenOfOwnerByIndex(address,uint256)')) == 0x2f745c59
+     *     bytes4(keccak256('tokenByIndex(uint256)')) == 0x4f6ccce7
+     *
+     *     => 0x18160ddd ^ 0x2f745c59 ^ 0x4f6ccce7 == 0x780e9d63
+     */
+    bytes4 private constant _INTERFACE_ID_ERC721_ENUMERABLE = 0x780e9d63;
+
+    /**
+     * @dev Constructor function.
+     */
+    constructor () public {
+        // register the supported interface to conform to ERC721Enumerable via ERC165
+        _registerInterface(_INTERFACE_ID_ERC721_ENUMERABLE);
+    }
+
+    /**
+     * @dev Gets the token ID at a given index of the tokens list of the requested owner.
+     * @param owner address owning the tokens list to be accessed
+     * @param index uint256 representing the index to be accessed of the requested tokens list
+     * @return uint256 token ID at the given index of the tokens list owned by the requested address
+     */
+    function tokenOfOwnerByIndex(address owner, uint256 index) public view returns (uint256) {
+        require(index < balanceOf(owner), "ERC721Enumerable: owner index out of bounds");
+        return _ownedTokens[owner][index];
+    }
+
+    /**
+     * @dev Gets the total amount of tokens stored by the contract.
+     * @return uint256 representing the total amount of tokens
+     */
+    function totalSupply() public view returns (uint256) {
+        return _allTokens.length;
+    }
+
+    /**
+     * @dev Gets the token ID at a given index of all the tokens in this contract
+     * Reverts if the index is greater or equal to the total number of tokens.
+     * @param index uint256 representing the index to be accessed of the tokens list
+     * @return uint256 token ID at the given index of the tokens list
+     */
+    function tokenByIndex(uint256 index) public view returns (uint256) {
+        require(index < totalSupply(), "ERC721Enumerable: global index out of bounds");
+        return _allTokens[index];
+    }
+
+    /**
+     * @dev Internal function to transfer ownership of a given token ID to another address.
+     * As opposed to transferFrom, this imposes no restrictions on msg.sender.
+     * @param from current owner of the token
+     * @param to address to receive the ownership of the given token ID
+     * @param tokenId uint256 ID of the token to be transferred
+     */
+    function _transferFrom(address from, address to, uint256 tokenId) internal {
+        super._transferFrom(from, to, tokenId);
+
+        _removeTokenFromOwnerEnumeration(from, tokenId);
+
+        _addTokenToOwnerEnumeration(to, tokenId);
+    }
+
+    /**
+     * @dev Internal function to mint a new token.
+     * Reverts if the given token ID already exists.
+     * @param to address the beneficiary that will own the minted token
+     * @param tokenId uint256 ID of the token to be minted
+     */
+    function _mint(address to, uint256 tokenId) internal {
+        super._mint(to, tokenId);
+
+        _addTokenToOwnerEnumeration(to, tokenId);
+
+        _addTokenToAllTokensEnumeration(tokenId);
+    }
+
+    /**
+     * @dev Internal function to burn a specific token.
+     * Reverts if the token does not exist.
+     * Deprecated, use _burn(uint256) instead.
+     * @param owner owner of the token to burn
+     * @param tokenId uint256 ID of the token being burned
+     */
+    function _burn(address owner, uint256 tokenId) internal {
+        super._burn(owner, tokenId);
+
+        _removeTokenFromOwnerEnumeration(owner, tokenId);
+        // Since tokenId will be deleted, we can clear its slot in _ownedTokensIndex to trigger a gas refund
+        _ownedTokensIndex[tokenId] = 0;
+
+        _removeTokenFromAllTokensEnumeration(tokenId);
+    }
+
+    /**
+     * @dev Gets the list of token IDs of the requested owner.
+     * @param owner address owning the tokens
+     * @return uint256[] List of token IDs owned by the requested address
+     */
+    function _tokensOfOwner(address owner) internal view returns (uint256[] storage) {
+        return _ownedTokens[owner];
+    }
+
+    /**
+     * @dev Private function to add a token to this extension's ownership-tracking data structures.
+     * @param to address representing the new owner of the given token ID
+     * @param tokenId uint256 ID of the token to be added to the tokens list of the given address
+     */
+    function _addTokenToOwnerEnumeration(address to, uint256 tokenId) private {
+        _ownedTokensIndex[tokenId] = _ownedTokens[to].length;
+        _ownedTokens[to].push(tokenId);
+    }
+
+    /**
+     * @dev Private function to add a token to this extension's token tracking data structures.
+     * @param tokenId uint256 ID of the token to be added to the tokens list
+     */
+    function _addTokenToAllTokensEnumeration(uint256 tokenId) private {
+        _allTokensIndex[tokenId] = _allTokens.length;
+        _allTokens.push(tokenId);
+    }
+
+    /**
+     * @dev Private function to remove a token from this extension's ownership-tracking data structures. Note that
+     * while the token is not assigned a new owner, the _ownedTokensIndex mapping is _not_ updated: this allows for
+     * gas optimizations e.g. when performing a transfer operation (avoiding double writes).
+     * This has O(1) time complexity, but alters the order of the _ownedTokens array.
+     * @param from address representing the previous owner of the given token ID
+     * @param tokenId uint256 ID of the token to be removed from the tokens list of the given address
+     */
+    function _removeTokenFromOwnerEnumeration(address from, uint256 tokenId) private {
+        // To prevent a gap in from's tokens array, we store the last token in the index of the token to delete, and
+        // then delete the last slot (swap and pop).
+
+        uint256 lastTokenIndex = _ownedTokens[from].length.sub(1);
+        uint256 tokenIndex = _ownedTokensIndex[tokenId];
+
+        // When the token to delete is the last token, the swap operation is unnecessary
+        if (tokenIndex != lastTokenIndex) {
+            uint256 lastTokenId = _ownedTokens[from][lastTokenIndex];
+
+            _ownedTokens[from][tokenIndex] = lastTokenId; // Move the last token to the slot of the to-delete token
+            _ownedTokensIndex[lastTokenId] = tokenIndex; // Update the moved token's index
+        }
+
+        // This also deletes the contents at the last position of the array
+        _ownedTokens[from].length--;
+
+        // Note that _ownedTokensIndex[tokenId] hasn't been cleared: it still points to the old slot (now occupied by
+        // lastTokenId, or just over the end of the array if the token was the last one).
+    }
+
+    /**
+     * @dev Private function to remove a token from this extension's token tracking data structures.
+     * This has O(1) time complexity, but alters the order of the _allTokens array.
+     * @param tokenId uint256 ID of the token to be removed from the tokens list
+     */
+    function _removeTokenFromAllTokensEnumeration(uint256 tokenId) private {
+        // To prevent a gap in the tokens array, we store the last token in the index of the token to delete, and
+        // then delete the last slot (swap and pop).
+
+        uint256 lastTokenIndex = _allTokens.length.sub(1);
+        uint256 tokenIndex = _allTokensIndex[tokenId];
+
+        // When the token to delete is the last token, the swap operation is unnecessary. However, since this occurs so
+        // rarely (when the last minted token is burnt) that we still do the swap here to avoid the gas cost of adding
+        // an 'if' statement (like in _removeTokenFromOwnerEnumeration)
+        uint256 lastTokenId = _allTokens[lastTokenIndex];
+
+        _allTokens[tokenIndex] = lastTokenId; // Move the last token to the slot of the to-delete token
+        _allTokensIndex[lastTokenId] = tokenIndex; // Update the moved token's index
+
+        // This also deletes the contents at the last position of the array
+        _allTokens.length--;
+        _allTokensIndex[tokenId] = 0;
+    }
+}
+
+// File: @openzeppelin/contracts/token/ERC721/IERC721Metadata.sol
+
+pragma solidity ^0.5.0;
+
+
+/**
+ * @title ERC-721 Non-Fungible Token Standard, optional metadata extension
+ * @dev See https://eips.ethereum.org/EIPS/eip-721
+ */
+contract IERC721Metadata is IERC721 {
+    function name() external view returns (string memory);
+    function symbol() external view returns (string memory);
+    function tokenURI(uint256 tokenId) external view returns (string memory);
+}
+
+// File: @openzeppelin/contracts/token/ERC721/ERC721Metadata.sol
+
+pragma solidity ^0.5.0;
+
+
+
+
+contract ERC721Metadata is ERC165, ERC721, IERC721Metadata {
+    // Token name
+    string private _name;
+
+    // Token symbol
+    string private _symbol;
+
+    // Optional mapping for token URIs
+    mapping(uint256 => string) private _tokenURIs;
+
+    /*
+     *     bytes4(keccak256('name()')) == 0x06fdde03
+     *     bytes4(keccak256('symbol()')) == 0x95d89b41
+     *     bytes4(keccak256('tokenURI(uint256)')) == 0xc87b56dd
+     *
+     *     => 0x06fdde03 ^ 0x95d89b41 ^ 0xc87b56dd == 0x5b5e139f
+     */
+    bytes4 private constant _INTERFACE_ID_ERC721_METADATA = 0x5b5e139f;
+
+    /**
+     * @dev Constructor function
+     */
+    constructor (string memory name, string memory symbol) public {
+        _name = name;
+        _symbol = symbol;
+
+        // register the supported interfaces to conform to ERC721 via ERC165
+        _registerInterface(_INTERFACE_ID_ERC721_METADATA);
+    }
+
+    /**
+     * @dev Gets the token name.
+     * @return string representing the token name
+     */
+    function name() external view returns (string memory) {
+        return _name;
+    }
+
+    /**
+     * @dev Gets the token symbol.
+     * @return string representing the token symbol
+     */
+    function symbol() external view returns (string memory) {
+        return _symbol;
+    }
+
+    /**
+     * @dev Returns an URI for a given token ID.
+     * Throws if the token ID does not exist. May return an empty string.
+     * @param tokenId uint256 ID of the token to query
+     */
+    function tokenURI(uint256 tokenId) external view returns (string memory) {
+        require(_exists(tokenId), "ERC721Metadata: URI query for nonexistent token");
+        return _tokenURIs[tokenId];
+    }
+
+    /**
+     * @dev Internal function to set the token URI for a given token.
+     * Reverts if the token ID does not exist.
+     * @param tokenId uint256 ID of the token to set its URI
+     * @param uri string URI to assign
+     */
+    function _setTokenURI(uint256 tokenId, string memory uri) internal {
+        require(_exists(tokenId), "ERC721Metadata: URI set of nonexistent token");
+        _tokenURIs[tokenId] = uri;
+    }
+
+    /**
+     * @dev Internal function to burn a specific token.
+     * Reverts if the token does not exist.
+     * Deprecated, use _burn(uint256) instead.
+     * @param owner owner of the token to burn
+     * @param tokenId uint256 ID of the token being burned by the msg.sender
+     */
+    function _burn(address owner, uint256 tokenId) internal {
+        super._burn(owner, tokenId);
+
+        // Clear metadata (if any)
+        if (bytes(_tokenURIs[tokenId]).length != 0) {
+            delete _tokenURIs[tokenId];
+        }
+    }
+}
+
+// File: @openzeppelin/contracts/token/ERC721/ERC721Full.sol
+
+pragma solidity ^0.5.0;
+
+
+
+
+/**
+ * @title Full ERC721 Token
+ * This implementation includes all the required and some optional functionality of the ERC721 standard
+ * Moreover, it includes approve all functionality using operator terminology
+ * @dev see https://eips.ethereum.org/EIPS/eip-721
+ */
+contract ERC721Full is ERC721, ERC721Enumerable, ERC721Metadata {
+    constructor (string memory name, string memory symbol) public ERC721Metadata(name, symbol) {
+        // solhint-disable-previous-line no-empty-blocks
+    }
+}
diff --git a/test/Color.test.js b/test/Color.test.js
new file mode 100644
index 0000000..fc97452
--- /dev/null
+++ b/test/Color.test.js
@@ -0,0 +1,73 @@
+const Color = artifacts.require('./Color.sol')
+
+require('chai')
+  .use(require('chai-as-promised'))
+  .should()
+
+contract('Color', (accounts) => {
+  let contract
+
+  before(async () => {
+    contract = await Color.deployed()
+  })
+
+  describe('deployment', async () => {
+    it('deploys successfully', async () => {
+      const address = contract.address
+      assert.notEqual(address, 0x0)
+      assert.notEqual(address, '')
+      assert.notEqual(address, null)
+      assert.notEqual(address, undefined)
+    })
+
+    it('has a name', async () => {
+      const name = await contract.name()
+      assert.equal(name, 'Color')
+    })
+
+    it('has a symbol', async () => {
+      const symbol = await contract.symbol()
+      assert.equal(symbol, 'COLOR')
+    })
+
+  })
+
+  describe('minting', async () => {
+
+    it('creates a new token', async () => {
+      const result = await contract.mint('#EC058E')
+      const totalSupply = await contract.totalSupply()
+      // SUCCESS
+      assert.equal(totalSupply, 1)
+      const event = result.logs[0].args
+      assert.equal(event.tokenId.toNumber(), 1, 'id is correct')
+      assert.equal(event.from, '0x0000000000000000000000000000000000000000', 'from is correct')
+      assert.equal(event.to, accounts[0], 'to is correct')
+
+      // FAILURE: cannot mint same color twice
+      await contract.mint('#EC058E').should.be.rejected;
+    })
+  })
+
+  describe('indexing', async () => {
+    it('lists colors', async () => {
+      // Mint 3 more tokens
+      await contract.mint('#5386E4')
+      await contract.mint('#FFFFFF')
+      await contract.mint('#000000')
+      const totalSupply = await contract.totalSupply()
+
+      let color
+      let result = []
+
+      for (var i = 1; i <= totalSupply; i++) {
+        color = await contract.colors(i - 1)
+        result.push(color)
+      }
+
+      let expected = ['#EC058E', '#5386E4', '#FFFFFF', '#000000']
+      assert.equal(result.join(','), expected.join(','))
+    })
+  })
+
+})