<filename>giraph-core/src/main/java/com/yammer/metrics/core/NoOpGuage.java
/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.yammer.metrics.core;

/**
 * A Metrics Gauge implementation that always returns null.
 * @param <T> Type of value returned by this Gauge.
 */
public class NoOpGuage<T> extends Gauge<T> {
  /** singleton instance for everyone to use */
  public static final NoOpGuage INSTANCE = new NoOpGuage();

  /** do not instantiate */
  public NoOpGuage() { }

  @Override
  public T value() { return null; }
}
