anchor.diff:    @override
     void paint(Canvas canvas, Size size) {
       final matrix = new Matrix4.identity();
  -    leftScale(matrix, _scale, _scale);
  +    preScale(matrix, _scale, _scale);
   
       _compositionLayer.draw(canvas, size, matrix, _alpha);
     }
  
positive.code: 
    @override
    Widget build(BuildContext context) {
      return new CustomPaint(
          painter: new LottiePainter(_compositionLayer), size: const Size(200.0, 200.0));
    }
  
    @override
  
negative.code:   }
  
    void _handleChange() {
      setState(() {
        _compositionLayer.progress = _animation.value;
      });
  