/*
 * 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 com.google.errorprone.annotations.CanIgnoreReturnValue;
import java.util.Map.Entry;
import java.util.Set;
import org.checkerframework.checker.nullness.qual.Nullable;

A set multimap which forwards all its method calls to another set multimap. Subclasses should
override one or more methods to modify the behavior of the backing multimap as desired per the decorator pattern.
default method warning: This class does not forward calls to 
default methods. Instead, it inherits their default implementations. When those implementations invoke methods, they invoke methods on the ForwardingSetMultimap. 
Author:
Kurt Alfred Kluever
Since:
3.0/**
 * A set multimap which forwards all its method calls to another set 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>.
 *
 * <p><b>{@code default} method warning:</b> This class does <i>not</i> forward calls to {@code
 * default} methods. Instead, it inherits their default implementations. When those implementations
 * invoke methods, they invoke methods on the {@code ForwardingSetMultimap}.
 *
 * @author Kurt Alfred Kluever
 * @since 3.0
 */
@GwtCompatible
public abstract class ForwardingSetMultimap<K, V> extends ForwardingMultimap<K, V>
    implements SetMultimap<K, V> {

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

  @Override
  public Set<Entry<K, V>> entries() {
    return delegate().entries();
  }

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

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

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