     
     /**
      *  @private
-     *  Called after super.updateDisplayList() finishes.
+     *  Called after super.updateDisplayList() finishes.  Also called by
+     *  createItemRenderers to recycle existing renderers that were added
+     *  to oldVirtualRendererIndices by the preceeding call to 
+     *  startVirtualLayout.
      * 
      *  Discard the ItemRenderers that aren't needed anymore, i.e. the ones
      *  not explicitly requested with getVirtualElementAt() during the most

    /**
     *  @private
     *  Called before super.updateDisplayList() if layout.useVirtualLayout=true.
     *  Copies virtualRendererIndices to oldRendererIndices, clears virtualRendererIndices
     *  (which will be repopulated by subsequence getVirtualElementAt() calls), and
     *  calls ensureTypicalElement().

                
                indexToRenderer[index] = elt;
            }

            addItemRendererToDisplayList(DisplayObject(elt));           
            setUpItemRenderer(elt, index, item);
            
