nit

Author: pan3793

hadoop-hdfs-project/hadoop-hdfs-client/src/main/java/org/apache/hadoop/hdfs/web/oauth2/ConfRefreshTokenBasedAccessTokenProvider.java

@@ -29,18 +29,9 @@
 import org.apache.hadoop.hdfs.web.URLConnectionFactory;
 import org.apache.hadoop.util.JsonSerialization;
 import org.apache.hadoop.util.Timer;
+
 import org.apache.http.HttpEntity;
 import org.apache.http.HttpStatus;
-
-import static org.apache.hadoop.hdfs.client.HdfsClientConfigKeys.OAUTH_CLIENT_ID_KEY;
-import static org.apache.hadoop.hdfs.client.HdfsClientConfigKeys.OAUTH_REFRESH_URL_KEY;
-import static org.apache.hadoop.hdfs.web.oauth2.OAuth2Constants.ACCESS_TOKEN;
-import static org.apache.hadoop.hdfs.web.oauth2.OAuth2Constants.CLIENT_ID;
-import static org.apache.hadoop.hdfs.web.oauth2.OAuth2Constants.EXPIRES_IN;
-import static org.apache.hadoop.hdfs.web.oauth2.OAuth2Constants.GRANT_TYPE;
-import static org.apache.hadoop.hdfs.web.oauth2.OAuth2Constants.REFRESH_TOKEN;
-import static org.apache.hadoop.hdfs.web.oauth2.Utils.notNull;
-
 import org.apache.http.client.config.RequestConfig;
 import org.apache.http.client.entity.EntityBuilder;
 import org.apache.http.client.methods.CloseableHttpResponse;
@@ -51,6 +42,15 @@
 import org.apache.http.impl.client.HttpClientBuilder;
 import org.apache.http.message.BasicNameValuePair;
 
+import static org.apache.hadoop.hdfs.client.HdfsClientConfigKeys.OAUTH_CLIENT_ID_KEY;
+import static org.apache.hadoop.hdfs.client.HdfsClientConfigKeys.OAUTH_REFRESH_URL_KEY;
+import static org.apache.hadoop.hdfs.web.oauth2.OAuth2Constants.ACCESS_TOKEN;
+import static org.apache.hadoop.hdfs.web.oauth2.OAuth2Constants.CLIENT_ID;
+import static org.apache.hadoop.hdfs.web.oauth2.OAuth2Constants.EXPIRES_IN;
+import static org.apache.hadoop.hdfs.web.oauth2.OAuth2Constants.GRANT_TYPE;
+import static org.apache.hadoop.hdfs.web.oauth2.OAuth2Constants.REFRESH_TOKEN;
+import static org.apache.hadoop.hdfs.web.oauth2.Utils.notNull;
+
 /**
  * Supply a access token obtained via a refresh token (provided through the
  * Configuration using the second half of the