     }
     
     /**
-     *  Removes a mask to a particular GraphicElement.  This is needed because the 
-     *  Group is managing the GraphicElement's DisplayObject.
+     *  @inheritDoc
      */
     public function removeMaskElement(mask:DisplayObject, target:IGraphicElement):void
     {

    }
    
    /**
     *  Adds a mask to a particular GraphicElement.  
     *  This is needed because the 
     *  Group is managing the GraphicElement's DisplayObject.
     */
    public function addMaskElement(mask:DisplayObject, target:IGraphicElement):void
    {

    //----------------------------------

    /**
     *  @inheritDoc
     */
    public function horizontalScrollPositionDelta(unit:uint):Number
    {
