         public var nodeLayerNames:Array = [];
         public var edgeLayerNames:Array = [];
 
-        private var nodeKeyToId:Object = {};
-        private var nodeIdToKey:Object = {};
-
-        private var edgeKeyToId:Object = {};
-        private var edgeIdToKey:Object = {};
-
-        public var nodeProperties:Array = [];
-        public var edgeProperties:Array = [];
+        private var nodeKeyToId:Object = null;
+        private var nodeIdToKey:Object = null;
+
+        private var edgeKeyToId:Object = null;
+        private var edgeIdToKey:Object = null;
 
         public function GraphMLDataSource()
         {


        private function translateReferences(idToKeyMappings:Object, values:Array):Array
        {
            return values.map(function(item) { return idToKeyMappings[item]; });
        }

        private function partitionElements(elements:Array, propertyName:String):Object

            return partitions;
        }

        public function setFile(content:Object):void
        {
            var results:Object = GraphMLConverter.parse(content as XML);

            // Store results.nodeKeys and results.edgeKeys somewhere
            
            nodeProperties.setSessionState(results.nodeKeys);
            nodeColumnData.setSessionState(results.nodes);

            edgeProperties.setSessionState(results.edgeKeys);
            edgeColumnData.setSessionState(results.edges);
        }
    }
