anchor.diff:        sortDirection: SortDirection.ascending,
       );
   
  -    return controller.instanceFieldsTreeTable;
  +    return _controller.instanceFieldsTreeTable!;
     }
   }
   
  
positive.code:     super.didChangeDependencies();
  
      final newController = Provider.of<MemoryController>(context);
      if (newController == controller) return;
      controller = newController;
  
      cancelListeners();
  
  
negative.code:     //              controller. Have other ValueListenables on controller to
      //              listen to, so we don't need the setState calls.
      // Update the chart when the memorySource changes.
      addAutoDisposeListener(_controller.selectedSnapshotNotifier, () {
        setState(() {
          _controller.computeAllLibraries(rebuild: true);
        });
      });
    }
  
    @override
    Widget build(BuildContext context) {
      _controller.instanceFieldsTreeTable = TreeTable<FieldReference>(
        dataRoots: _controller.instanceRoot!,
        columns: columns,
        treeColumn: treeColumn,
        keyFactory: (typeRef) => PageStorageKey<String>(typeRef.name),
  