Clean up spring-messaging imports

spring-messaging is full of unused imports. This commit removes all
unused imports from spring-messaging.

spring-messaging/src/test/java/org/springframework/messaging/converter/MessageConverterTests.java

@@ -5,7 +5,7 @@
  * 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
+ *      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,
@@ -33,7 +33,6 @@ import org.springframework.util.MimeType;
 import org.springframework.util.MimeTypeUtils;
 
 import static org.junit.Assert.*;
-import static org.junit.Assert.assertEquals;
 
 /**
  * Unit tests for

spring-messaging/src/test/java/org/springframework/messaging/converter/SimpleMessageConverterTests.java

@@ -5,7 +5,7 @@
  * 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
+ *      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,
@@ -23,7 +23,6 @@ import org.springframework.messaging.MessageHeaders;
 import org.springframework.messaging.support.MessageHeaderAccessor;
 
 import java.util.Collections;
-import java.util.Map;
 
 import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertNull;

spring-messaging/src/test/java/org/springframework/messaging/simp/SimpMessagingTemplateTests.java

@@ -5,7 +5,7 @@
  * 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
+ *      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,
@@ -16,7 +16,6 @@
 
 package org.springframework.messaging.simp;
 
-import org.apache.activemq.transport.stomp.Stomp;
 import org.junit.Before;
 import org.junit.Test;
 import org.springframework.messaging.Message;

spring-messaging/src/test/java/org/springframework/messaging/simp/annotation/support/SendToMethodReturnValueHandlerTests.java

@@ -5,7 +5,7 @@
  * 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
+ *      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,
@@ -36,7 +36,6 @@ import org.springframework.messaging.Message;
 import org.springframework.messaging.MessageChannel;
 import org.springframework.messaging.MessageHeaders;
 import org.springframework.messaging.converter.StringMessageConverter;
-import org.springframework.messaging.core.MessageSendingOperations;
 import org.springframework.messaging.handler.DestinationPatternsMessageCondition;
 import org.springframework.messaging.handler.annotation.SendTo;
 import org.springframework.messaging.simp.SimpMessageHeaderAccessor;
@@ -50,7 +49,6 @@ import org.springframework.util.MimeType;
 
 import static org.junit.Assert.*;
 import static org.mockito.Matchers.*;
-import static org.mockito.Matchers.eq;
 import static org.mockito.Mockito.*;
 
 /**

spring-messaging/src/test/java/org/springframework/messaging/simp/stomp/StompHeaderAccessorTests.java

@@ -5,7 +5,7 @@
  * 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
+ *      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,
@@ -35,7 +35,6 @@ import org.springframework.util.MimeTypeUtils;
 import org.springframework.util.MultiValueMap;
 
 import static org.junit.Assert.*;
-import static org.junit.Assert.assertEquals;
 
 /**
  * Unit tests for {@link StompHeaderAccessor}.

spring-messaging/src/test/java/org/springframework/messaging/support/MessageHeaderAccessorTests.java

@@ -5,7 +5,7 @@
  * 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
+ *      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,
@@ -30,7 +30,6 @@ import org.springframework.messaging.MessageHeaders;
 import org.springframework.util.IdGenerator;
 
 import static org.junit.Assert.*;
-import static org.junit.Assert.assertEquals;
 
 /**
  * Test fixture for {@link MessageHeaderAccessor}.

spring-messaging/src/test/java/org/springframework/messaging/support/NativeMessageHeaderAccessorTests.java

@@ -5,7 +5,7 @@
  * 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
+ *      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,
@@ -19,7 +19,6 @@ package org.springframework.messaging.support;
 import java.util.Arrays;
 import java.util.Collections;
 import java.util.HashMap;
-import java.util.HashSet;
 import java.util.List;
 import java.util.Map;
 
@@ -31,7 +30,6 @@ import org.springframework.util.LinkedMultiValueMap;
 import org.springframework.util.MultiValueMap;
 
 import static org.junit.Assert.*;
-import static org.junit.Assert.assertEquals;
 
 /**
  * Test fixture for {@link NativeMessageHeaderAccessor}.