anchor.diff:        final data = trace.DataAggregate(
           sample.timestamp,
           MemoryEventsPaneState.extensionEvent,
  -        events.extensionEvents.theEvents.length,
  +        (events.extensionEvents?.theEvents ?? []).length,
         );
         addDataToTrace(TraceName.extensionEvents.index, data);
       }
  
positive.code:     final monitorResetIndex = _chartController.createTrace(
        trace.ChartType.symbol,
        trace.PaintCharacteristics.concentric(
          color: Colors.grey[600],
          strokeWidth: 4,
          diameter: 6,
          fixedMinY: visibleVmEvent,
  
negative.code: 
    MemoryTimeline get _memoryTimeline => _memoryController.memoryTimeline;
  
    @override
    void initState() {
      super.initState();
  