如何在Flutter中自定义带有翻转动画的AnimatedCrossFade？

import 'package:flutter/material.dart';

class MyAnimatedCrossFade extends StatefulWidget {
  @override
  _MyAnimatedCrossFadeState createState() => _MyAnimatedCrossFadeState();
}

class _MyAnimatedCrossFadeState extends State<MyAnimatedCrossFade> {
  bool _isFirstWidgetVisible = true;

  void _toggleWidget() {
    setState(() {
      _isFirstWidgetVisible = !_isFirstWidgetVisible;
    });
  }

  @override
  Widget build(BuildContext context) {
    return Column(
      children: [
        AnimatedCrossFade(
          firstChild: FirstWidget(),
          secondChild: SecondWidget(),
          crossFadeState: _isFirstWidgetVisible
              ? CrossFadeState.showFirst
              : CrossFadeState.showSecond,
          duration: Duration(seconds: 1),
        ),
        RaisedButton(
          onPressed: _toggleWidget,
          child: Text('Toggle Widget'),
        ),
      ],
    );
  }
}

class FirstWidget extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return Container(
      width: 200,
      height: 200,
      color: Colors.blue,
      child: Center(
        child: Text(
          'First Widget',
          style: TextStyle(color: Colors.white, fontSize: 20),
        ),
      ),
    );
  }
}

class SecondWidget extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return Container(
      width: 200,
      height: 200,
      color: Colors.red,
      child: Center(
        child: Text(
          'Second Widget',
          style: TextStyle(color: Colors.white, fontSize: 20),
        ),
      ),
    );
  }
}

void main() {
  runApp(MaterialApp(
    home: Scaffold(
      appBar: AppBar(
        title: Text('AnimatedCrossFade Example'),
      ),
      body: MyAnimatedCrossFade(),
    ),
  ));
}