anchor.diff:  }
   
   
  -class _AnimatedCircleAvatar extends Container {
  +class _AnimatedCircleAvatar extends StatelessWidget {
   
     final AnimationController controller;
     final double radius;
  +  final Color baseColor;
  +  final Color selectedColor;
   
  -  _AnimatedCircleAvatar({this.controller, this.radius, color})
  -      : super(
  -    decoration: new BoxDecoration(
  -      shape: BoxShape.circle,
  -      color: color,
  -    ),
  -    width: radius * 2,
  -    height: radius * 2,
  -  );
  +  _AnimatedCircleAvatar({
  +    Key key,
  +    this.controller,
  +    this.radius,
  +    this.baseColor,
  +    this.selectedColor
  +    }) : super(key: key);
   
     @override
     Widget build(BuildContext context) {
  +    Container selctedCircle = new Container(
  +      decoration: new BoxDecoration(
  +        shape: BoxShape.circle,
  +        color: selectedColor,
  +      ),
  +      width: radius * 2,
  +      height: radius * 2
  +    );
  +
       return new Stack(
         alignment: FractionalOffset.center,
         children: <Widget>[
  
positive.code: 
    Row items;
  
    _CircleIndicatorState(this.pagerController, this.size, this.radius,
        this.baseColor, this.selectedColor) {
      pagerController.addListener(animate);
      List<Container> icons = new List();
      for (int i = 0; i < size; i++) {
        icons.add(new Container(
          margin: new EdgeInsets.all(4.0),
  
negative.code:     with TickerProviderStateMixin {
    final PageController pagerController;
    final int size;
  
    int oldPage = 0;
    int page = 0;
  