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Types that extend and augment the Java Collections Framework.
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/*
 *  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.collections.map;

import java.util.Collection;
import java.util.Map;
import java.util.Set;

/**
 * Provides a base decorator that enables additional functionality to be added
 * to a Map via decoration.
 * 
 * Methods are forwarded directly to the decorated map.
 * 
 * This implementation does not perform any special processing with
 * {@link #entrySet()}, {@link #keySet()} or {@link #values()}. Instead
 * it simply returns the set/collection from the wrapped map. This may be
 * undesirable, for example if you are trying to write a validating
 * implementation it would provide a loophole around the validation.
 * But, you might want that loophole, so this class is kept simple.
 *
 * @since Commons Collections 3.0
 * @version $Revision: 646777 $ $Date: 2008-04-10 14:33:15 +0200 (Thu, 10 Apr 2008) $
 * 
 * @author Daniel Rall
 * @author Stephen Colebourne
 */
public abstract class AbstractMapDecorator implements Map {

    /** The map to decorate */
    protected transient Map map;

    /**
     * Constructor only used in deserialization, do not use otherwise.
     * @since Commons Collections 3.1
     */
    protected AbstractMapDecorator() {
        super();
    }

    /**
     * Constructor that wraps (not copies).
     *
     * @param map  the map to decorate, must not be null
     * @throws IllegalArgumentException if the collection is null
     */
    public AbstractMapDecorator(Map map) {
        if (map == null) {
            throw new IllegalArgumentException("Map must not be null");
        }
        this.map = map;
    }

    /**
     * Gets the map being decorated.
     * 
     * @return the decorated map
     */
    protected Map getMap() {
        return map;
    }

    //-----------------------------------------------------------------------
    public void clear() {
        map.clear();
    }

    public boolean containsKey(Object key) {
        return map.containsKey(key);
    }

    public boolean containsValue(Object value) {
        return map.containsValue(value);
    }

    public Set entrySet() {
        return map.entrySet();
    }

    public Object get(Object key) {
        return map.get(key);
    }

    public boolean isEmpty() {
        return map.isEmpty();
    }

    public Set keySet() {
        return map.keySet();
    }

    public Object put(Object key, Object value) {
        return map.put(key, value);
    }

    public void putAll(Map mapToCopy) {
        map.putAll(mapToCopy);
    }

    public Object remove(Object key) {
        return map.remove(key);
    }

    public int size() {
        return map.size();
    }

    public Collection values() {
        return map.values();
    }
   
    public boolean equals(Object object) {
        if (object == this) {
            return true;
        }
        return map.equals(object);
    }

    public int hashCode() {
        return map.hashCode();
    }

    public String toString() {
        return map.toString();
    }

}