content: /*
   * ContactMap.java January 2010
   *
   * Copyright (C) 2010, Niall Gallagher <niallg@users.sf.net>
   *
   * 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.aliyun.odps.simpleframework.xml.core;
  
  import java.util.Iterator;
  import java.util.LinkedHashMap;
  
  /**
   * The <code>ContactMap</code> object is used to keep track of the
   * contacts that have been processed. Keeping track of the contacts
   * that have been processed ensures that no two contacts are used
   * twice. This ensures a consistent XML class schema.
   * 
   * @author Niall Gallagher
   */
  class ContactMap extends LinkedHashMap<Object, Contact> implements Iterable<Contact> {
     
     /**
      * This is used to iterate over the <code>Contact</code> objects
      * in a for each loop. Iterating over the contacts allows them
      * to be easily added to a list of unique contacts.
      * 
      * @return this is used to return the contacts registered
      */
     public Iterator<Contact> iterator(){
        return values().iterator();
     }
     
  }