     private var _layer:GraphMLLayerNode;
     private var _columnName:String;
 
+
+
     public function get layer():GraphMLLayerNode
     {
         return _layer;

    
    public function getColumnMetadata():Object 
    {
        var metadata:Object = {
            column: columnName,
            filterValue: layer.filterValue,
            group: layer.group.group,
            filterColumn: layer.group.filterColumn
        };

        return metadata;
    }

            return _rootNode;
        }



        override public function getAttributeColumn(metadata:Object):IAttributeColumn
