 			var proxyColumn:ProxyColumn = request.proxyColumn;
 			var hierarchyNode:XML = HierarchyUtils.getLeafNodeFromPath(pathInHierarchy);
 			// if the node does not exist in hierarchy anymore, create a new XML separate from the hierarchy.
-			if (hierarchyNode == null)
+			if (!hierarchyNode)
 				hierarchyNode = <attribute/>;
 			else
 				proxyColumn.setMetadata(hierarchyNode);

	
				//trace("handleGetDataServiceMetadata",ObjectUtil.toString(event));

				if (_attributeHierarchy.value == null)
					_attributeHierarchy.value = <hierarchy/>;
				
				// add each missing category

		
		private function generateRootHierarchy(tables:Array, geoms:Array):void
		{
			if (objectWasDisposed(this) || !(_attributeHierarchy.value == <hierarchy/> || !_attributeHierarchy.value))
				return;

			var tag:XML;
