anchor.diff:                curve: Curves.linear,
                 reverseCurve: Curves.bounceOut
             ),
  -          child: super.build(context),
  +          child: selctedCircle,
           ),
           new Container(
             width: radius,
             height: radius,
             decoration: new BoxDecoration(
  -            color: Colors.white70,
  +            color: baseColor,
               shape: BoxShape.circle,
             ),
           ),
  
positive.code: }
  
  
  class _AnimatedCircleAvatar extends Container {
  
    final AnimationController controller;
    final double radius;
  
    _AnimatedCircleAvatar({this.controller, this.radius, color})
        : super(
      decoration: new BoxDecoration(
        shape: BoxShape.circle,
        color: color,
      ),
      width: radius * 2,
      height: radius * 2,
    );
  
    @override
    Widget build(BuildContext context) {
      return new Stack(
        alignment: FractionalOffset.center,
        children: <Widget>[
  
negative.code:             duration: new Duration(milliseconds: 100),
              vsync: this,
            ),
            baseColor: baseColor,
            selectedColor: selectedColor,
            radius: radius,
          ),
        ));
  