anchor.diff:  }
   
   class MemoryEventsPane extends StatefulWidget {
  -  const MemoryEventsPane(this.chartController, {Key key}) : super(key: key);
  +  const MemoryEventsPane(this.chartController, {Key? key}) : super(key: key);
   
     final EventChartController chartController;
   
  
positive.code: // Copyright 2020 The Chromium Authors. All rights reserved.
  // Use of this source code is governed by a BSD-style license that can be
  // found in the LICENSE file.
  
  // @dart=2.9
  
  import 'package:devtools_shared/devtools_shared.dart';
  import 'package:flutter/material.dart';
  
negative.code:     final monitorResetIndex = _chartController.createTrace(
        trace.ChartType.symbol,
        trace.PaintCharacteristics.concentric(
          color: Colors.grey[600]!,
          strokeWidth: 4,
          diameter: 6,
          fixedMinY: visibleVmEvent,
  