diff --git a/src/main/java/org/tikv/PDClient.java b/src/main/java/org/tikv/PDClient.java
index de142cd092..822aaa760e 100644
--- a/src/main/java/org/tikv/PDClient.java
+++ b/src/main/java/org/tikv/PDClient.java
@@ -34,7 +34,6 @@ import org.tikv.codec.Codec.BytesCodec;
 import org.tikv.codec.CodecDataOutput;
 import org.tikv.exception.GrpcException;
 import org.tikv.exception.TiClientInternalException;
-import org.tikv.kvproto.Kvrpcpb.IsolationLevel;
 import org.tikv.kvproto.Metapb.Store;
 import org.tikv.kvproto.PDGrpc;
 import org.tikv.kvproto.PDGrpc.PDBlockingStub;
diff --git a/src/main/java/org/tikv/TiSession.java b/src/main/java/org/tikv/TiSession.java
index aca1d3579e..f3e4f7aa83 100644
--- a/src/main/java/org/tikv/TiSession.java
+++ b/src/main/java/org/tikv/TiSession.java
@@ -22,7 +22,6 @@ import java.util.HashMap;
 import java.util.Map;
 import java.util.concurrent.TimeUnit;
 import java.util.function.Function;
-
 import org.tikv.event.CacheInvalidateEvent;
 import org.tikv.region.RegionManager;
 
@@ -100,5 +99,5 @@ public class TiSession implements AutoCloseable {
   }
 
   @Override
-  public void close() throws Exception { }
+  public void close() throws Exception {}
 }