如何了解animated_text_kit包中当前播放的文本？

import 'package:flutter/material.dart';
import 'package:animated_text_kit/animated_text_kit.dart';

void main() {
  runApp(MyApp());
}

class MyApp extends StatelessWidget {
  final GlobalKey<AnimatedTextKitState> animatedTextKitKey =
      GlobalKey<AnimatedTextKitState>();

  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      home: Scaffold(
        appBar: AppBar(
          title: Text('Animated Text Kit Example'),
        ),
        body: Center(
          child: Column(
            mainAxisAlignment: MainAxisAlignment.center,
            children: [
              AnimatedTextKit(
                key: animatedTextKitKey,
                animatedTexts: [
                  TypewriterAnimatedText('Hello'),
                  TypewriterAnimatedText('World'),
                ],
              ),
              RaisedButton(
                child: Text('Get Current Text'),
                onPressed: () {
                  String currentText =
                      animatedTextKitKey.currentState.currentText;
                  print('Current Text: $currentText');
                },
              ),
            ],
          ),
        ),
      ),
    );
  }
}