         const newColumns:IList = _columns;
         if (newColumns)
         {
-            newColumns.addEventListener(CollectionEvent.COLLECTION_CHANGE, columns_collectionChangeHandler, false, 0, true);            
+            newColumns.addEventListener(CollectionEvent.COLLECTION_CHANGE, columns_collectionChangeHandler, false, 0, true);
             for (index = 0; index < newColumns.length; index++)
             {
                 var newColumn:GridColumn = GridColumn(newColumns.getItemAt(index));

        invalidateDisplayList();        
    } 
    
    //--------------------------------------------------------------------------
    //
    //  Methods

import mx.events.CollectionEvent;
import mx.events.CollectionEventKind;
import mx.events.FlexEvent;
import mx.events.PropertyChangeEvent;
import mx.utils.ObjectUtil;

import spark.components.supportClasses.CellPosition;
