anchor.diff:    EffectLine({
       required this.texture,
       this.transferMode = BlendMode.dstOver,
  -    required List<Offset> points,
  +    List<Offset>? points,
       this.widthMode = EffectLineWidthMode.linear,
       this.minWidth = 10.0,
       this.maxWidth = 10.0,
  
positive.code:   late List<Offset> _points;
  
    late List<double> _pointAges;
    late List<Color> _colors;
    late List<double> _widths;
  
    /// The time it takes for an added point to fade out. It's total life time is
    /// [fadeDuration] + [fadeAfterDelay].
  
negative.code:     this.simplify = true,
      ColorSequence? colorSequence,
    }) {
      this.points = points ?? [];
  
      _colorSequence = colorSequence;
      _colorSequence ??= ColorSequence.fromStartAndEndColor(
  