diff --git a/CHANGELOG.md b/CHANGELOG.md
index 4b48783..f329660 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,3 +1,8 @@
+# 1.0.1
+
+- Removed unnecessary builders
+- Improved test coverage
+
 # 1.0
 
 - Initial commit
diff --git a/pom.xml b/pom.xml
index 8b27800..f15e57e 100644
--- a/pom.xml
+++ b/pom.xml
@@ -6,7 +6,7 @@
 
     <groupId>io.github.sanyarnd</groupId>
     <artifactId>app-locker</artifactId>
-    <version>1.0</version>
+    <version>1.0.1</version>
     <url>https://github.com/sanyarnd/applocker</url>
     <packaging>jar</packaging>
 
@@ -33,7 +33,6 @@
         <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
 
         <java-version>1.8</java-version>
-        <!--<maven.compiler.release>${java-version}</maven.compiler.release>-->
         <maven.compiler.source>${java-version}</maven.compiler.source>
         <maven.compiler.target>${java-version}</maven.compiler.target>
         <maven.compiler.useIncrementalCompilation>true</maven.compiler.useIncrementalCompilation>
@@ -147,7 +146,6 @@
                     <analyzer>
                         <outputType>xml</outputType>
                         <outputFile>target/reports/pvs-output.xml</outputFile>
-                        <!--<sonarQubeData>sonar-project.properties</sonarQubeData>-->
                     </analyzer>
                 </configuration>
             </plugin>
diff --git a/src/main/java/io/github/sanyarnd/applocker/AppLocker.java b/src/main/java/io/github/sanyarnd/applocker/AppLocker.java
index 66cd017..fbe15db 100644
--- a/src/main/java/io/github/sanyarnd/applocker/AppLocker.java
+++ b/src/main/java/io/github/sanyarnd/applocker/AppLocker.java
@@ -23,6 +23,7 @@
 import java.nio.file.Files;
 import java.nio.file.NoSuchFileException;
 import java.nio.file.Path;
+import java.nio.file.Paths;
 import java.util.function.BiConsumer;
 import java.util.function.Consumer;
 
@@ -32,14 +33,14 @@
 import lombok.Getter;
 import lombok.ToString;
 
-import io.github.sanyarnd.applocker.builder.Builder;
-import io.github.sanyarnd.applocker.builder.BuilderArgs;
 import io.github.sanyarnd.applocker.exceptions.LockingBusyException;
 import io.github.sanyarnd.applocker.exceptions.LockingCommunicationException;
 import io.github.sanyarnd.applocker.exceptions.LockingException;
 import io.github.sanyarnd.applocker.exceptions.LockingFailedException;
 import io.github.sanyarnd.applocker.filesystem.LockNameProvider;
+import io.github.sanyarnd.applocker.filesystem.Sha1Provider;
 import io.github.sanyarnd.applocker.messaging.Client;
+import io.github.sanyarnd.applocker.messaging.MessageHandler;
 import io.github.sanyarnd.applocker.messaging.Server;
 
 /**
@@ -75,13 +76,13 @@ public final class AppLocker {
     @Nonnull
     private final Consumer<LockingException> failedHandler;
 
-    public AppLocker(@Nonnull String id,
-                     @Nonnull Path lockPath,
-                     @Nonnull LockNameProvider provider,
-                     @Nullable Server<?, ?> server,
-                     @Nonnull Runnable acquiredHandler,
-                     @Nullable BiConsumer<AppLocker, LockingBusyException> busyHandler,
-                     @Nonnull Consumer<LockingException> failedHandler) {
+    private AppLocker(@Nonnull String id,
+                      @Nonnull Path lockPath,
+                      @Nonnull LockNameProvider provider,
+                      @Nullable Server<?, ?> server,
+                      @Nonnull Runnable acquiredHandler,
+                      @Nullable BiConsumer<AppLocker, LockingBusyException> busyHandler,
+                      @Nonnull Consumer<LockingException> failedHandler) {
         this.id = id;
         this.server = server;
         this.acquiredHandler = acquiredHandler;
@@ -105,7 +106,7 @@ public AppLocker(@Nonnull String id,
      * @param id AppLocker unique ID
      * @return builder
      */
-    public static BuilderArgs create(@Nonnull String id) {
+    public static Builder create(@Nonnull String id) {
         return new Builder(id);
     }
 
@@ -221,5 +222,118 @@ private int getPortFromFile() throws IOException {
         return ByteBuffer.wrap(Files.readAllBytes(portFile)).getInt();
     }
 
+    /**
+     * AppLocker builder
+     *
+     * @author Alexander Biryukov
+     */
+    public static final class Builder {
+        @Nonnull
+        private final String id;
+        @Nonnull
+        private Path path = Paths.get(".");
+        @Nonnull
+        private LockNameProvider provider = new Sha1Provider();
+        @Nullable
+        private MessageHandler<?, ?> handler = null;
+        @Nonnull
+        private Runnable acquiredHandler = () -> {};
+        @Nonnull
+        private Consumer<LockingException> failedHandler = ex -> { throw ex; };
+        @Nullable
+        private BiConsumer<AppLocker, LockingBusyException> busyHandler;
+
+        public Builder(@Nonnull String id) { this.id = id; }
+
+        /**
+         * Sets the path where the lock file will be stored<br/>
+         * Default value is "." (relative)
+         *
+         * @param path store path
+         * @return builder
+         */
+        public Builder setPath(@Nonnull Path path) {
+            this.path = path;
+            return this;
+        }
+
+        /**
+         * Sets the message handler.<br/>
+         * If not set, AppLocker won't support communication features <br/>
+         * Default value is null
+         *
+         * @param handler message handler
+         * @return builder
+         */
+        public Builder setMessageHandler(@Nonnull MessageHandler<?, ?> handler) {
+            this.handler = handler;
+            return this;
+        }
+
+        /**
+         * Sets the name provider.<br/>
+         * Provider encodes lock id to filesystem-friendly entry<br/>
+         * Default value is {@link Sha1Provider}
+         *
+         * @param provider name provider
+         * @return builder
+         */
+        public Builder setNameProvider(@Nonnull LockNameProvider provider) {
+            this.provider = provider;
+            return this;
+        }
 
+        /**
+         * Successful locking callback.<br/>
+         * By default does nothing
+         *
+         * @param callback the function to call after successful locking
+         * @return builder
+         */
+        public Builder acquired(@Nonnull Runnable callback) {
+            acquiredHandler = callback;
+            return this;
+        }
+
+        /**
+         * Lock is already taken callback.<br/>
+         * By default does nothing (null)
+         *
+         * @param message message for lock holder
+         * @param handler answer processing function
+         * @param <T>     answer type
+         * @return builder
+         */
+        public <T extends Serializable> Builder busy(@Nonnull Serializable message, @Nonnull Consumer<T> handler) {
+            busyHandler = (appLocker, ex) -> {
+                T answer = appLocker.sendMessage(message);
+                handler.accept(answer);
+            };
+            return this;
+        }
+
+        /**
+         * Unable to lock for unknown reasons callback.<br/>
+         * By default re-throws the exception
+         *
+         * @param handler error processing function
+         * @return builder
+         */
+        public Builder failed(@Nonnull Consumer<LockingException> handler) {
+            failedHandler = handler;
+            return this;
+        }
+
+        /**
+         * Build AppLocker
+         *
+         * @return AppLocker instance
+         */
+        public AppLocker build() {
+            @SuppressWarnings("unchecked")
+            Server<?, ?> server = handler != null ? new Server(handler) : null;
+
+            return new AppLocker(id, path, provider, server, acquiredHandler, busyHandler, failedHandler);
+        }
+    }
 }
diff --git a/src/main/java/io/github/sanyarnd/applocker/builder/Builder.java b/src/main/java/io/github/sanyarnd/applocker/builder/Builder.java
deleted file mode 100644
index 1b66d86..0000000
--- a/src/main/java/io/github/sanyarnd/applocker/builder/Builder.java
+++ /dev/null
@@ -1,107 +0,0 @@
-// This is an open source non-commercial project. Dear PVS-Studio, please check it.
-// PVS-Studio Static Code Analyzer for C, C++, C#, and Java: http://www.viva64.com
-//
-//                     Copyright 2019 Alexander Biryukov
-//
-//     Licensed under the Apache License, Version 2.0 (the "License");
-//     you may not use this file except in compliance with the License.
-//     You may obtain a copy of the License at
-//
-//               http://www.apache.org/licenses/LICENSE-2.0
-//
-//     Unless required by applicable law or agreed to in writing, software
-//     distributed under the License is distributed on an "AS IS" BASIS,
-//     WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-//     See the License for the specific language governing permissions and
-//     limitations under the License.
-
-package io.github.sanyarnd.applocker.builder;
-
-import java.io.Serializable;
-import java.nio.file.Path;
-import java.nio.file.Paths;
-import java.util.function.BiConsumer;
-import java.util.function.Consumer;
-
-import javax.annotation.Nonnull;
-import javax.annotation.Nullable;
-
-import io.github.sanyarnd.applocker.AppLocker;
-import io.github.sanyarnd.applocker.exceptions.LockingBusyException;
-import io.github.sanyarnd.applocker.exceptions.LockingException;
-import io.github.sanyarnd.applocker.filesystem.LockNameProvider;
-import io.github.sanyarnd.applocker.filesystem.Sha1Provider;
-import io.github.sanyarnd.applocker.messaging.MessageHandler;
-import io.github.sanyarnd.applocker.messaging.Server;
-
-/**
- * AppLocker builder
- *
- * @author Alexander Biryukov
- */
-public final class Builder implements BuilderCommunicationArgs, BuilderArgs {
-    @Nonnull
-    private final String id;
-    @Nonnull
-    private Path path = Paths.get(".");
-    @Nonnull
-    private LockNameProvider provider = new Sha1Provider();
-    @Nullable
-    private MessageHandler<?, ?> handler = null;
-    @Nonnull
-    private Runnable acquiredHandler = () -> {};
-    @Nonnull
-    private Consumer<LockingException> failedHandler = ex -> { throw ex; };
-    @Nullable
-    private BiConsumer<AppLocker, LockingBusyException> busyHandler;
-
-    public Builder(@Nonnull String id) { this.id = id; }
-
-    @Override
-    public BuilderArgs setPath(@Nonnull Path path) {
-        this.path = path;
-        return this;
-    }
-
-    @Override
-    public BuilderArgs setMessageHandler(@Nonnull MessageHandler<?, ?> handler) {
-        this.handler = handler;
-        return this;
-    }
-
-    @Override
-    public BuilderArgs setNameProvider(@Nonnull LockNameProvider provider) {
-        this.provider = provider;
-        return this;
-    }
-
-    @Override
-    public BuilderArgs acquired(@Nonnull Runnable callback) {
-        acquiredHandler = callback;
-        return this;
-    }
-
-    @Override
-    public <T extends Serializable> BuilderCommunicationArgs busy(@Nonnull Serializable message, @Nonnull Consumer<T> handler) {
-        busyHandler = (appLocker, ex) -> {
-            T answer = appLocker.sendMessage(message);
-            handler.accept(answer);
-        };
-        return this;
-    }
-
-    @Override
-    public BuilderArgs failed(@Nonnull Consumer<LockingException> handler) {
-        failedHandler = handler;
-
-        return this;
-    }
-
-    @Override
-    public AppLocker build() {
-        @SuppressWarnings("unchecked")
-        Server<?, ?> server = handler != null ? new Server(handler) : null;
-
-        return new AppLocker(id, path, provider, server, acquiredHandler, busyHandler, failedHandler);
-    }
-}
diff --git a/src/main/java/io/github/sanyarnd/applocker/builder/BuilderArgs.java b/src/main/java/io/github/sanyarnd/applocker/builder/BuilderArgs.java
deleted file mode 100644
index 0df1637..0000000
--- a/src/main/java/io/github/sanyarnd/applocker/builder/BuilderArgs.java
+++ /dev/null
@@ -1,86 +0,0 @@
-// This is an open source non-commercial project. Dear PVS-Studio, please check it.
-// PVS-Studio Static Code Analyzer for C, C++, C#, and Java: http://www.viva64.com
-//
-//                     Copyright 2019 Alexander Biryukov
-//
-//     Licensed under the Apache License, Version 2.0 (the "License");
-//     you may not use this file except in compliance with the License.
-//     You may obtain a copy of the License at
-//
-//               http://www.apache.org/licenses/LICENSE-2.0
-//
-//     Unless required by applicable law or agreed to in writing, software
-//     distributed under the License is distributed on an "AS IS" BASIS,
-//     WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-//     See the License for the specific language governing permissions and
-//     limitations under the License.
-
-package io.github.sanyarnd.applocker.builder;
-
-import java.io.Serializable;
-import java.nio.file.Path;
-import java.util.function.Consumer;
-
-import javax.annotation.Nonnull;
-
-import io.github.sanyarnd.applocker.AppLocker;
-import io.github.sanyarnd.applocker.exceptions.LockingException;
-import io.github.sanyarnd.applocker.filesystem.LockNameProvider;
-import io.github.sanyarnd.applocker.filesystem.Sha1Provider;
-
-public interface BuilderArgs {
-    /**
-     * Sets the path where the lock file will be stored<br/>
-     * Default value is "." (relative)
-     *
-     * @param path store path
-     * @return builder
-     */
-    BuilderArgs setPath(@Nonnull Path path);
-
-    /**
-     * Sets the name provider.<br/>
-     * Provider encodes lock id to filesystem-friendly entry<br/>
-     * Default value is {@link Sha1Provider}
-     *
-     * @param provider name provider
-     * @return builder
-     */
-    BuilderArgs setNameProvider(@Nonnull LockNameProvider provider);
-
-    /**
-     * Successful locking callback.<br/>
-     * By default does nothing
-     *
-     * @param callback the function to call after successful locking
-     * @return builder
-     */
-    BuilderArgs acquired(@Nonnull Runnable callback);
-
-    /**
-     * Unable to lock for unknown reasons callback.<br/>
-     * By default re-throws the exception
-     *
-     * @param handler error processing function
-     * @return builder
-     */
-    BuilderArgs failed(@Nonnull Consumer<LockingException> handler);
-
-    /**
-     * Lock is already taken callback.<br/>
-     * By default does nothing (null)
-     *
-     * @param message message for lock holder
-     * @param handler answer processing function
-     * @param <T>     answer type
-     * @return builder
-     */
-    <T extends Serializable> BuilderCommunicationArgs busy(@Nonnull Serializable message, @Nonnull Consumer<T> handler);
-
-    /**
-     * Build AppLocker
-     *
-     * @return AppLocker instance
-     */
-    AppLocker build();
-}
diff --git a/src/main/java/io/github/sanyarnd/applocker/builder/BuilderCommunicationArgs.java b/src/main/java/io/github/sanyarnd/applocker/builder/BuilderCommunicationArgs.java
deleted file mode 100644
index d053ee9..0000000
--- a/src/main/java/io/github/sanyarnd/applocker/builder/BuilderCommunicationArgs.java
+++ /dev/null
@@ -1,34 +0,0 @@
-// This is an open source non-commercial project. Dear PVS-Studio, please check it.
-// PVS-Studio Static Code Analyzer for C, C++, C#, and Java: http://www.viva64.com
-//
-//                     Copyright 2019 Alexander Biryukov
-//
-//     Licensed under the Apache License, Version 2.0 (the "License");
-//     you may not use this file except in compliance with the License.
-//     You may obtain a copy of the License at
-//
-//               http://www.apache.org/licenses/LICENSE-2.0
-//
-//     Unless required by applicable law or agreed to in writing, software
-//     distributed under the License is distributed on an "AS IS" BASIS,
-//     WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-//     See the License for the specific language governing permissions and
-//     limitations under the License.
-
-package io.github.sanyarnd.applocker.builder;
-
-import javax.annotation.Nonnull;
-
-import io.github.sanyarnd.applocker.messaging.MessageHandler;
-
-public interface BuilderCommunicationArgs {
-    /**
-     * Sets the message handler.<br/>
-     * If not set, AppLocker won't support communication features <br/>
-     * Default value is null
-     *
-     * @param handler message handler
-     * @return builder
-     */
-    BuilderArgs setMessageHandler(@Nonnull MessageHandler<?, ?> handler);
-}
diff --git a/src/test/java/io/github/sanyarnd/applocker/AppLockerHandlersTest.java b/src/test/java/io/github/sanyarnd/applocker/AppLockerHandlersTest.java
index c0c7060..bb81df0 100644
--- a/src/test/java/io/github/sanyarnd/applocker/AppLockerHandlersTest.java
+++ b/src/test/java/io/github/sanyarnd/applocker/AppLockerHandlersTest.java
@@ -51,7 +51,7 @@ public void fail_handler_suppress_exception() {
         Assertions.assertTrue(l1.isLocked());
         Assertions.assertFalse(l2.isLocked());
         // test that failed handler is called
-        Assertions.assertEquals(ret[0], -1);
+        Assertions.assertEquals(-1, ret[0]);
 
         // cleanup
         l1.unlock();
@@ -70,7 +70,7 @@ public void busy_handler_supersedes_fail_handler_when_suppressing_exception() {
         Assertions.assertFalse(l2.isLocked());
 
         // test that busy handler is called
-        Assertions.assertEquals(ret[0], 1);
+        Assertions.assertEquals(1, ret[0]);
 
         // cleanup
         l1.unlock();
@@ -91,7 +91,7 @@ public void fail_handler_supersedes_fail_handler_when_busy_throws_exception() {
         Assertions.assertTrue(l1.isLocked());
         Assertions.assertFalse(l2.isLocked());
         // test that failed handler is called
-        Assertions.assertEquals(ret[0], -1);
+        Assertions.assertEquals(-1, ret[0]);
 
         // cleanup
         l1.unlock();
@@ -106,7 +106,7 @@ public void lock_acquired_is_called() {
         l1.lock();
         Assertions.assertTrue(l1.isLocked());
         // test that failed handler is called
-        Assertions.assertEquals(ret[0], 1);
+        Assertions.assertEquals(1, ret[0]);
 
         // cleanup
         l1.unlock();
diff --git a/src/test/java/io/github/sanyarnd/applocker/AppLockerTest.java b/src/test/java/io/github/sanyarnd/applocker/AppLockerTest.java
index 23b7329..46b238f 100644
--- a/src/test/java/io/github/sanyarnd/applocker/AppLockerTest.java
+++ b/src/test/java/io/github/sanyarnd/applocker/AppLockerTest.java
@@ -121,7 +121,7 @@ public void communication_to_self() {
         l1.lock();
 
         String messageToSelf = l1.sendMessage("self");
-        Assertions.assertEquals(messageToSelf, "self");
+        Assertions.assertEquals("self", messageToSelf);
 
         // cleanup
         l1.unlock();
@@ -135,7 +135,7 @@ public void communication_between_two_locks() {
         l1.lock();
 
         String messageToOther = l2.sendMessage("other");
-        Assertions.assertEquals(messageToOther, "other");
+        Assertions.assertEquals("other", messageToOther);
 
         // cleanup
         l1.unlock();
@@ -170,13 +170,13 @@ public String handleMessage(@Nonnull String message) {
 
         l1.lock();
         String messageToOther = l2.sendMessage("whatever");
-        Assertions.assertEquals(messageToOther, "1");
+        Assertions.assertEquals("1", messageToOther);
 
         l1.unlock();
 
         l2.lock();
         messageToOther = l1.sendMessage("whatever");
-        Assertions.assertEquals(messageToOther, "2");
+        Assertions.assertEquals("2", messageToOther);
 
         // cleanup
         l1.unlock();
@@ -199,6 +199,12 @@ public String encrypt(@Nonnull String string) {
         l1.unlock();
     }
 
+    @Test
+    public void to_string() {
+        AppLocker l1 = AppLocker.create("sameId").build();
+        Assertions.assertNotEquals(l1.toString(), null);
+    }
+
     @Test
     @EnabledOnOs(OS.WINDOWS)
     public void invalid_path_windows_throws() {
diff --git a/src/test/java/io/github/sanyarnd/applocker/MessagingTest.java b/src/test/java/io/github/sanyarnd/applocker/MessagingTest.java
index d07e06b..fd3a3e4 100644
--- a/src/test/java/io/github/sanyarnd/applocker/MessagingTest.java
+++ b/src/test/java/io/github/sanyarnd/applocker/MessagingTest.java
@@ -17,6 +17,7 @@
 
 package io.github.sanyarnd.applocker;
 
+import java.io.EOFException;
 import java.io.Serializable;
 import java.util.ArrayList;
 
@@ -26,6 +27,7 @@
 import org.junit.jupiter.api.Test;
 
 import io.github.sanyarnd.applocker.exceptions.LockingCommunicationException;
+import io.github.sanyarnd.applocker.exceptions.LockingMessageServerException;
 import io.github.sanyarnd.applocker.messaging.Client;
 import io.github.sanyarnd.applocker.messaging.MessageHandler;
 import io.github.sanyarnd.applocker.messaging.Server;
@@ -105,6 +107,25 @@ public void client_throws_if_no_server() {
         Assertions.assertThrows(LockingCommunicationException.class, () -> client.send(message));
     }
 
+    @Test
+    public void port_throws_if_no_server() {
+        final Server<String, String> server = new Server<>(createEchoHandler());
+
+        Assertions.assertThrows(LockingCommunicationException.class, server::getPort);
+    }
+
+    @Test
+    public void port_throws_if_server_exception() {
+        final Server<String, String> server = new Server<>(e -> {
+            throw new IllegalArgumentException();
+        });
+
+        server.start();
+        final Client<String, String> client = new Client<>(server.getPortBlocking());
+        Assertions.assertThrows(LockingCommunicationException.class, () -> client.send("test"));
+        Assertions.assertThrows(LockingMessageServerException.class, server::getPortBlocking);
+    }
+
     @Test
     public void client_throws_1_if_types_do_not_match() {
         MessageHandler<String, String> echoHandler = createEchoHandler();