Nullable value type may be null.

This async method lacks 'await' operators and will run synchronously. Consider using the 'await' operator to await non-blocking API calls, or 'await Task.Run(...)' to do CPU-bound work on a background thread.

Converting null literal or possible null value to non-nullable type.

Dereference of a possibly null reference.

Converting null literal or possible null value to non-nullable type.

Possible null reference argument for parameter 'transaction' in 'Keccak TransactionExtensions.CalculateHash(Transaction transaction)'.

Converting null literal or possible null value to non-nullable type.

Possible null reference argument for parameter 'item' in 'Rlp TxDecoder<Transaction>.Encode(Transaction item, RlpBehaviors rlpBehaviors = RlpBehaviors.None)'.

Possible null reference argument for parameter 'expected' in 'AndConstraint<ComparableTypeAssertions<Keccak>> ComparableTypeAssertions<Keccak, ComparableTypeAssertions<Keccak>>.Be(Keccak expected, string because = "", params object[] becauseArgs)'.