Remove some unused imports

Author: aarondav

network/shuffle/src/main/java/org/apache/spark/network/shuffle/ExternalShuffleBlockHandler.java

@@ -21,8 +21,6 @@
 
 import com.google.common.annotations.VisibleForTesting;
 import com.google.common.collect.Lists;
-import io.netty.buffer.ByteBuf;
-import io.netty.buffer.Unpooled;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
@@ -36,7 +34,6 @@
 import org.apache.spark.network.shuffle.protocol.OpenBlocks;
 import org.apache.spark.network.shuffle.protocol.RegisterExecutor;
 import org.apache.spark.network.shuffle.protocol.StreamHandle;
-import org.apache.spark.network.util.JavaUtils;
 
 /**
  * RPC Handler for a server which can serve shuffle blocks from outside of an Executor process.

network/shuffle/src/main/java/org/apache/spark/network/shuffle/ExternalShuffleClient.java

@@ -21,8 +21,6 @@
 import java.util.List;
 
 import com.google.common.collect.Lists;
-import io.netty.buffer.ByteBuf;
-import io.netty.buffer.Unpooled;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
@@ -34,7 +32,6 @@
 import org.apache.spark.network.sasl.SecretKeyHolder;
 import org.apache.spark.network.server.NoOpRpcHandler;
 import org.apache.spark.network.shuffle.protocol.ExecutorShuffleInfo;
-import org.apache.spark.network.shuffle.protocol.OpenBlocks;
 import org.apache.spark.network.shuffle.protocol.RegisterExecutor;
 import org.apache.spark.network.util.TransportConf;