 			
 			return new ColumnTreeNode({
 				dataSource: this,
-				idFields: META_ID_FIELDS,
+				idFields: [META_SERIES_ID, META_COLUMN_NAME],
 				data: metadata
 			});
 		}
-        
+		
+		//TODO - use http://api.stlouisfed.org/docs/fred/series_categories.html
+		
         override protected function requestColumnFromSource(proxyColumn:ProxyColumn):void
         {
             var series:String = proxyColumn.getMetadata(META_SERIES_ID);

			}
			return csv;
		}
			
		public function createSeriesNode(data:Object):IWeaveTreeNode
		{
			return new ColumnTreeNode({
				dataSource: this,
				label: data.title,
				data: data,
				hasChildBranches: false,
				children: function(node:ColumnTreeNode):Array {
					var csv:CSVDataSource = getObservationsCSV(data.id);

			});
		}
		
		public static const META_CATEGORY_ID:String = 'FRED_category_id';
		public static const META_SERIES_ID:String = 'FRED_series_id';
		public static const META_COLUMN_NAME:String = 'FRED_column_name';
		
		override protected function generateHierarchyNode(metadata:Object):IWeaveTreeNode
		{
