saw6.dart

saw6.dart

return PlayAnimation<double>( // <-- set animatino type
  duration: 800.milliseconds,
  curve: Curves.easeInOut,
  tween: 0.0.tweenTo(200.0), // <-- double tween
  builder: (context, child, value) {
    return Container( // <-- return a Container
      width: value, // <-- use animated value for width
      height: value, // <-- use animated value for height
      color: Colors.green,
    );
  },
);