 import flash.events.Event;
 import flash.events.EventDispatcher;
 
+import mx.collections.SortField;
 import mx.core.ClassFactory;
 import mx.core.IFactory;
-import mx.core.IIMESupport;
-import mx.core.Singleton;
 import mx.core.mx_internal;
 import mx.events.CollectionEvent;
 import mx.events.CollectionEventKind;
 import mx.events.PropertyChangeEvent;
+import mx.utils.ObjectUtil;
 
 import spark.components.DataGrid;
 import spark.components.Grid;

    
    private var _sortable:Boolean = true;
    
    [Bindable("sortableChanged")]  
    
    /**
     *  TBD
     * 
     *  @default true
     */
    public function get sortable():Boolean

        return _defaultItemEditorFactory;
    }

    //--------------------------------------------------------------------------
    //
    //  Constructor
    //
    //--------------------------------------------------------------------------
    
    /**
     *  Constructor. 
     *  
     *  @langversion 3.0
     *  @playerversion Flash 10
     *  @playerversion AIR 2.0
     *  @productversion Flex 4.5
     */
    public function GridColumn()
    {
        super();
