颤动/火焰恢复-类型'List<dynamic>‘不是类型'Widget’的子类型

AnimationController controller;
Animation<double> animation;

@override
void initState() {
  super.initState();
  controller = AnimationController(
    duration: const Duration(milliseconds: 500),
    vsync: this,
  );
  animation = Tween(begin: 0.0, end: 1.0).animate(controller);
  controller.repeat(reverse: true);
}

@override
void dispose() {
  controller.dispose();
  super.dispose();
}

@override
Widget build(BuildContext context) {
  return AnimatedBuilder(
    animation: animation,
    builder: (BuildContext context, Widget child) {
      return Transform.scale(
        scale: animation.value,
        child: child,
      );
    },
    child: Container(
      width: 100,
      height: 100,
      color: Colors.red,
    ),
  );
}