/*
    * 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 org.apache.commons.collections4.multimap;
  
  import java.io.Serializable;
  import java.util.Collection;
  import java.util.Map;
  import java.util.Map.Entry;
  import java.util.Objects;
  import java.util.Set;
  
  import org.apache.commons.collections4.MapIterator;
  import org.apache.commons.collections4.MultiSet;
  import org.apache.commons.collections4.MultiValuedMap;
  
  /**
   * Decorates another {@code MultiValuedMap} to provide additional behavior.
   * <p>
   * Each method call made on this {@code MultiValuedMap} is forwarded to the
   * decorated {@code MultiValuedMap}. This class is used as a framework to build
   * to extensions such as synchronized and unmodifiable behavior.
   * </p>
   *
   * @param <K> the type of key elements
   * @param <V> the type of value elements
   *
   * @since 4.1
   */
  public abstract class AbstractMultiValuedMapDecorator<K, V>
          implements MultiValuedMap<K, V>, Serializable {
  
      /** Serialization version */
      private static final long serialVersionUID = 20150612L;
  
      /** MultiValuedMap to decorate */
      private final MultiValuedMap<K, V> map;
  
      /**
       * Constructor that wraps (not copies).
       *
       * @param map  the map to decorate, must not be null
       * @throws NullPointerException if the map is null
       */
      protected AbstractMultiValuedMapDecorator(final MultiValuedMap<K, V> map) {
          this.map = Objects.requireNonNull(map, "map");
      }
  
      @Override
      public Map<K, Collection<V>> asMap() {
          return decorated().asMap();
      }
  
      @Override
      public void clear() {
          decorated().clear();
      }
  
      @Override
      public boolean containsKey(final Object key) {
          return decorated().containsKey(key);
      }
  
      @Override
      public boolean containsMapping(final Object key, final Object value) {
          return decorated().containsMapping(key, value);
      }
  
      @Override
      public boolean containsValue(final Object value) {
          return decorated().containsValue(value);
      }
  
      /**
       * The decorated multivalued map.
       *
       * @return the map to decorate
       */
      protected MultiValuedMap<K, V> decorated() {
          return map;
      }
  
      @Override
      public Collection<Entry<K, V>> entries() {
          return decorated().entries();
      }
 
     @Override
     public boolean equals(final Object object) {
         if (object == this) {
             return true;
         }
         return decorated().equals(object);
     }
 
     @Override
     public Collection<V> get(final K key) {
         return decorated().get(key);
     }
 
     @Override
     public int hashCode() {
         return decorated().hashCode();
     }
 
     @Override
     public boolean isEmpty() {
         return decorated().isEmpty();
     }
 
     @Override
     public MultiSet<K> keys() {
         return decorated().keys();
     }
 
     @Override
     public Set<K> keySet() {
         return decorated().keySet();
     }
 
     @Override
     public MapIterator<K, V> mapIterator() {
         return decorated().mapIterator();
     }
 
     @Override
     public boolean put(final K key, final V value) {
         return decorated().put(key, value);
     }
 
     @Override
     public boolean putAll(final K key, final Iterable<? extends V> values) {
         return decorated().putAll(key, values);
     }
 
     @Override
     public boolean putAll(final Map<? extends K, ? extends V> map) {
         return decorated().putAll(map);
     }
 
     @Override
     public boolean putAll(final MultiValuedMap<? extends K, ? extends V> map) {
         return decorated().putAll(map);
     }
 
     @Override
     public Collection<V> remove(final Object key) {
         return decorated().remove(key);
     }
 
     @Override
     public boolean removeMapping(final Object key, final Object item) {
         return decorated().removeMapping(key, item);
     }
 
     @Override
     public int size() {
         return decorated().size();
     }
 
     @Override
     public String toString() {
         return decorated().toString();
     }
 
     @Override
     public Collection<V> values() {
         return decorated().values();
     }
 
 }