     mx_internal var headerClass:Class = DataGridHeader;
 
     /**
-     *  @private
+     *  
      */
     protected var headerMask:Shape;
 


    /**
     *  Calculates the row height of columns in a row.
     *  If <code>skipVisible</code> is <code>true></code> 
     *  the DataGridBase already knows the height of
     *  the renderers for the column that do fit in the display area
     *  so this method only needs to calculate for the item renderers
     *  that would exist if other columns in that row were in the
     *  display area.  This is needed so that if the user scrolls
     *  horizontally, the height of the row does not adjust as different
     *  columns appear and disappear.
     *

    }

    /** 
     *  Ensures that there is a slot in the row arrays for the given row number.
     *  
     *  @param contentHolder The set of rows (locked rows, regular rows).
     *  
     *  @param rowNum The row number.
     */
    protected function prepareRowArray(contentHolder:ListBaseContentHolder, rowNum:int):void
