 	import weave.api.data.IDataSource;
 	import weave.api.getCallbackCollection;
 	import weave.api.newLinkableChild;
+	import weave.api.registerLinkableChild;
 	import weave.data.AttributeColumns.CSVColumn;
 	import weave.data.AttributeColumns.EquationColumn;
 	import weave.data.AttributeColumns.ProxyColumn;

		private var _root:ILinkableHashMap = WeaveAPI.globalHashMap;
		
		/**
		 * attributeHierarchy
		 * @return An AttributeHierarchy object that will be updated when new pieces of the hierarchy are filled in.
		 */
		private const _attributeHierarchy:AttributeHierarchy = newLinkableChild(this, AttributeHierarchy);

			
			return WeaveAPI.AttributeColumnCache.getColumn(columnReference);
		}
	}
}