anchor.diff:    )
   ];
   
  -Iterable _placeholderData = const [
  -  const [1317452400000, 0.0, 0.0],
  -  const [1317538800000, 0.0, 0.0],
  -];
  +Iterable _getPlaceholderData() {
  +  DateTime now = new DateTime.now();
  +
  +  return [
  +    [now.subtract(new Duration(days: 30)).millisecondsSinceEpoch, 0.0, 0.0],
  +    [now.millisecondsSinceEpoch, 0.0, 0.0],
  +  ];
  +}
  
positive.code:     DivElement areaHost = wrapper.querySelector('.chart-host');
      DivElement legendHost = wrapper.querySelector('.chart-legend-host');
  
      data ??= _placeholderData;
  
      ChartData chartData = new ChartData(_columnSpecs, data);
      ChartSeries series = new ChartSeries("Flutter Analysis Times", [1, 2], new LineChartRenderer());
  
negative.code: }
  
  Iterable _columnSpecs = [
    new ChartColumnSpec(
      label: 'Time',
      type: ChartColumnSpec.TYPE_TIMESTAMP
    ),
    new ChartColumnSpec(
      label: 'flutter analyze flutter-repo',
  