anchor.diff:          children: [
             Expanded(child: _buildChart()),
             const SizedBox(width: defaultSpacing),
  -          _buildChartLegend(),
  +          Column(
  +            mainAxisAlignment: MainAxisAlignment.spaceBetween,
  +            crossAxisAlignment: CrossAxisAlignment.start,
  +            children: [
  +              _buildChartLegend(),
  +              if (widget.frames.isNotEmpty) _buildAverageFps(),
  +            ],
  +          ),
           ],
         ),
       );
  
positive.code: // Copyright 2019 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.
  
  import 'package:flutter/material.dart';
  import 'package:provider/provider.dart';
  
negative.code:     );
  
      // Max FPS non-jank value in ms. E.g., 16.6 for 60 FPS, 8.3 for 120 FPS.
      final targetMsPerFrame = 1000 / displayRefreshRate;
      final targetLineY = constraints.maxHeight - targetMsPerFrame / msPerPx;
  
      canvas.drawLine(
  