guava/src/com/google/common/collect/ForwardingListMultimap.java

/*
 * Copyright (C) 2010 The Guava Authors
 *
 * Licensed 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.google.common.collect;

import com.google.common.annotations.GwtCompatible;

import java.util.List;

import javax.annotation.Nullable;

/**
 * A list multimap which forwards all its method calls to another list multimap.
 * Subclasses should override one or more methods to modify the behavior of
 * the backing multimap as desired per the <a
 * href="http://en.wikipedia.org/wiki/Decorator_pattern">decorator pattern</a>.
 *
 * @author Kurt Alfred Kluever
 * @since 3.0
 */
@GwtCompatible
public abstract class ForwardingListMultimap<K, V>
    extends ForwardingMultimap<K, V> implements ListMultimap<K, V> {

  /** Constructor for use by subclasses. */
  protected ForwardingListMultimap() {}

  @Override protected abstract ListMultimap<K, V> delegate();

  @Override public List<V> get(@Nullable K key) {
    return delegate().get(key);
  }

  @Override public List<V> removeAll(@Nullable Object key) {
    return delegate().removeAll(key);
  }

  @Override public List<V> replaceValues(K key, Iterable<? extends V> values) {
    return delegate().replaceValues(key, values);
  }
}