[FLINK-8241][tests] Remove ResultPartitionWriter-related "@PrepareForTest" annotations

This closes #5147.

flink-runtime/src/test/java/org/apache/flink/runtime/io/network/api/writer/RecordWriterTest.java

@@ -74,7 +74,7 @@ import static org.mockito.Mockito.times;
 import static org.mockito.Mockito.verify;
 import static org.mockito.Mockito.when;
 
-@PrepareForTest({ResultPartitionWriter.class, EventSerializer.class})
+@PrepareForTest({EventSerializer.class})
 @RunWith(PowerMockRunner.class)
 public class RecordWriterTest {
 

flink-runtime/src/test/java/org/apache/flink/runtime/io/network/api/writer/ResultPartitionWriterTest.java

@@ -30,16 +30,11 @@ import org.apache.flink.runtime.io.network.partition.ResultPartitionManager;
 import org.apache.flink.runtime.io.network.partition.ResultPartitionType;
 import org.apache.flink.runtime.taskmanager.TaskActions;
 import org.junit.Test;
-import org.junit.runner.RunWith;
-import org.powermock.core.classloader.annotations.PrepareForTest;
-import org.powermock.modules.junit4.PowerMockRunner;
 
 import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertTrue;
 import static org.mockito.Mockito.mock;
 
-@PrepareForTest({ResultPartitionWriter.class})
-@RunWith(PowerMockRunner.class)
 public class ResultPartitionWriterTest {
 
 	// ---------------------------------------------------------------------------------------------

flink-runtime/src/test/java/org/apache/flink/runtime/operators/chaining/ChainTaskTest.java

@@ -29,7 +29,6 @@ import org.apache.flink.runtime.testutils.recordutils.RecordComparatorFactory;
 import org.apache.flink.runtime.testutils.recordutils.RecordSerializerFactory;
 import org.apache.flink.api.common.functions.RichGroupReduceFunction;
 import org.apache.flink.configuration.Configuration;
-import org.apache.flink.runtime.io.network.api.writer.ResultPartitionWriter;
 import org.apache.flink.runtime.operators.DriverStrategy;
 import org.apache.flink.runtime.operators.BatchTask;
 import org.apache.flink.runtime.operators.FlatMapDriver;
@@ -51,7 +50,7 @@ import org.powermock.core.classloader.annotations.PrepareForTest;
 import org.powermock.modules.junit4.PowerMockRunner;
 
 @RunWith(PowerMockRunner.class)
-@PrepareForTest({Task.class, ResultPartitionWriter.class})
+@PrepareForTest({Task.class})
 @PowerMockIgnore({"javax.management.*", "com.sun.jndi.*"})
 public class ChainTaskTest extends TaskTestBase {
 	

flink-runtime/src/test/java/org/apache/flink/runtime/operators/chaining/ChainedAllReduceDriverTest.java

@@ -22,7 +22,6 @@ import org.apache.flink.api.common.functions.FlatMapFunction;
 import org.apache.flink.api.common.functions.ReduceFunction;
 import org.apache.flink.api.common.operators.util.UserCodeClassWrapper;
 import org.apache.flink.configuration.Configuration;
-import org.apache.flink.runtime.io.network.api.writer.ResultPartitionWriter;
 import org.apache.flink.runtime.operators.BatchTask;
 import org.apache.flink.runtime.operators.DriverStrategy;
 import org.apache.flink.runtime.operators.FlatMapDriver;
@@ -46,7 +45,7 @@ import java.util.ArrayList;
 import java.util.List;
 
 @RunWith(PowerMockRunner.class)
-@PrepareForTest({Task.class, ResultPartitionWriter.class})
+@PrepareForTest({Task.class})
 public class ChainedAllReduceDriverTest extends TaskTestBase {
 
 	private static final int MEMORY_MANAGER_SIZE = 1024 * 1024 * 3;

flink-streaming-java/src/test/java/org/apache/flink/streaming/runtime/io/StreamRecordWriterTest.java

@@ -41,8 +41,7 @@ import static org.mockito.Mockito.mock;
 import static org.mockito.Mockito.when;
 
 /**
- * This test uses the PowerMockRunner runner to work around the fact that the
- * {@link ResultPartitionWriter} class is final.
+ * Tests for the {@link StreamRecordWriter}.
  */
 public class StreamRecordWriterTest {
 

flink-streaming-java/src/test/java/org/apache/flink/streaming/runtime/tasks/StreamTaskTestHarness.java

@@ -58,9 +58,6 @@ import java.util.concurrent.LinkedBlockingQueue;
  * <p>After setting up everything the Task can be invoked using {@link #invoke()}. This will start
  * a new Thread to execute the Task. Use {@link #waitForTaskCompletion()} to wait for the Task
  * thread to finish.
- *
- * <p>When using this you need to add the following line to your test class to setup Powermock:
- * {@code {@literal @}PrepareForTest({ResultPartitionWriter.class})}
  */
 public class StreamTaskTestHarness<OUT> {