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1   /**
2    * Licensed to the Apache Software Foundation (ASF) under one
3    * or more contributor license agreements.  See the NOTICE file
4    * distributed with this work for additional information
5    * regarding copyright ownership.  The ASF licenses this file
6    * to you under the Apache License, Version 2.0 (the
7    * "License"); you may not use this file except in compliance
8    * with the License.  You may obtain a copy of the License at
9    *
10   *     http://www.apache.org/licenses/LICENSE-2.0
11   *
12   * Unless required by applicable law or agreed to in writing, software
13   * distributed under the License is distributed on an "AS IS" BASIS,
14   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
15   * See the License for the specific language governing permissions and
16   * limitations under the License.
17   */
18  package org.apache.hadoop.hbase.zookeeper;
19  
20  import org.apache.hadoop.classification.InterfaceAudience;
21  import org.apache.zookeeper.WatchedEvent;
22  import org.apache.zookeeper.Watcher;
23  
24  /**
25   * An empty ZooKeeper watcher
26   */
27  @InterfaceAudience.Private
28  public class EmptyWatcher implements Watcher {
29    // Used in this package but also by tests so needs to be public
30    public static final EmptyWatcher instance = new EmptyWatcher();
31    private EmptyWatcher() {}
32  
33    public void process(WatchedEvent event) {}
34  }