HADOOP-14458. Add missing imports to TestAliyunOSSFileSystemContract.java. Contributed by Mingliang Liu.

hadoop-tools/hadoop-aliyun/src/test/java/org/apache/hadoop/fs/aliyun/oss/TestAliyunOSSFileSystemContract.java

@@ -20,17 +20,22 @@ package org.apache.hadoop.fs.aliyun.oss;
 
 import org.apache.hadoop.conf.Configuration;
 import org.apache.hadoop.fs.FileAlreadyExistsException;
+import org.apache.hadoop.fs.FileStatus;
 import org.apache.hadoop.fs.FileSystemContractBaseTest;
 import org.apache.hadoop.fs.Path;
+
 import org.junit.Before;
 import org.junit.Test;
 
-import static org.junit.Assume.*;
-import org.apache.hadoop.fs.FileStatus;
-
 import java.io.FileNotFoundException;
 import java.io.IOException;
 
+import static org.junit.Assert.assertFalse;
+import static org.junit.Assert.assertTrue;
+import static org.junit.Assert.fail;
+import static org.junit.Assume.assumeNotNull;
+import static org.junit.Assume.assumeTrue;
+
 /**
  * Tests a live Aliyun OSS system.
  *