     /**
      *  @private
      */
-    protected function addItemsToContainer(dest:Container, items:Array):void
+    protected function addItemsToContainer(dest:IChildList, items:Array):void
     {
         if (startIndex == -1)
             startIndex = dest.numChildren;

    /**
     *  @private
     */
    protected function addItemsToArrayCollection(list:IList, items:Array):void
    {       
        if (startIndex == -1)
            startIndex = list.length;

    /**
     *  @private
     */
    protected function removeItemsFromIList(list:IList):void
    {
        for (var i:int = 0; i < numAdded; i++)
            list.removeItemAt(startIndex);
