      *  previous message that this message refers to.
      *
      *  @see mx.messaging.messages.AbstractMessage#messageId
+     *  
+     *  @langversion 3.0
+     *  @playerversion Flash 9
+     *  @playerversion AIR 1.1
+     *  @productversion BlazeDS 4
+     *  @productversion LCDS 3 
      */
     public function get correlationId():String
     {

	/**
	 *  Messages sent by a MessageAgent with a defined <code>subtopic</code>
	 *  property indicate their target subtopic in this header.
	 */
	public static const SUBTOPIC_HEADER:String = "DSSubtopic";    


     *  @param body The optional body to assign to the message.
     * 
     *  @param headers The optional headers to assign to the message.
     *  
     *  @langversion 3.0
     *  @playerversion Flash 9
     *  @playerversion AIR 1.1
     *  @productversion BlazeDS 4
     *  @productversion LCDS 3 
     */
    public function AsyncMessage(body:Object = null, headers:Object = null)
    {
