library/src/main/java/com/datatorrent/lib/util/BaseKeyOperator.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.datatorrent.lib.util;

import com.datatorrent.common.util.BaseOperator;

/**
 * This is an abstract operator that allows cloneKey to allow users to use mutable objects.
 * <p></p>
 * @displayName Base Key
 * @category Algorithmic
 * @tags abstract, cloneKey
 * @since 0.3.2
 */
public class BaseKeyOperator<K> extends BaseOperator
{
  /**
   * Override this call in case you have mutable objects. By default the objects are assumed to be immutable
   * @param k to be cloned
   * @return k as is
   */
  public K cloneKey(K k)
  {
    return k;
  }
}