     import spark.components.supportClasses.CellPosition;
     import spark.components.supportClasses.GridColumn;
     import spark.components.supportClasses.GridDimensions;
-    import spark.components.supportClasses.GridLayer;    
+    import spark.components.supportClasses.GridLayer;
     import spark.components.supportClasses.GridLayout;
     import spark.components.supportClasses.GridSelection;
     import spark.components.supportClasses.GridSelectionMode;

        //
        //  GridLayout Cover Methods, Properties
        //
        //--------------------------------------------------------------------------   
        
        /**
         *  If necessary, set the verticalScrollPosition and horizontalScrollPosition 

         */
        public function ensureCellIsVisible(rowIndex:int, columnIndex:int = -1):void
        {
            if ((rowIndex < 0) || (rowIndex >= dataProvider.length))  // TBD check for invalid column
                return;
            
            // A cell's index as defined by LayoutBase it's just its position
            // in the row-major linear ordering of the grid's cells.  
            
            const elementIndex:int = (rowIndex * dataProvider.length) + ((columnIndex < 0) ? 0 : columnIndex);
            const scrollHorizontally:Boolean = columnIndex != -1;
            
            // Iterate until we've scrolled elementIndex at least partially into view.
            do
            {
                scrollToIndex(elementIndex, scrollHorizontally);
                if (variableRowHeight || scrollHorizontally)
                    validateNow();
                else
                    break;  // fixed row heights, and we're only scrolling vertically
            }
            while(!isCellVisible(rowIndex, columnIndex))
            
            // At this point we've only ensured that the requested cell is at least 
            // partially visible.  Ensure that it's completely visible.
          
            scrollToIndex(elementIndex, scrollHorizontally);
        }        
        
        /**
