     //----------------------------------
     
     [Bindable]
-    [SkinPart(required="false", type="spark.components.GridColumnHeaderGroup")]
+    [SkinPart(required="false")]
     
     /**
      *  A reference to the GridColumnHeaderGroup object that displays the column headers.

    //----------------------------------
    
    [Bindable]
    [SkinPart(required="false", type="mx.core.IFactory")]
    
    /**
     *  The IVisualElement class used to render the grid's caret indicator.

    //----------------------------------
    
    [Bindable]
    [SkinPart(required="false", type="mx.core.IVisualElement")]
    
    /**
     *  The IVisualElement class used to render the vertical separator between columns. 
