构建StreamBuilder<UserData>时抛出以下NoSuchMethodError (脏，状态：_StreamBuilderBaseState<UserData，AsyncSnapshot<UserData>>)：

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flutter pub deps

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

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

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      home: Scaffold(
        appBar: AppBar(
          title: Text('StreamBuilder Example'),
        ),
        body: StreamBuilder<UserData>(
          stream: getUserDataStream(), // 假设这是一个返回 Stream<UserData> 的方法
          builder: (BuildContext context, AsyncSnapshot<UserData> snapshot) {
            if (snapshot.hasData) {
              return Center(child: Text('User Data: ${snapshot.data}'));
            } else if (snapshot.hasError) {
              return Center(child: Text('Error: ${snapshot.error}'));
            } else {
              return Center(child: CircularProgressIndicator());
            }
          },
        ),
      ),
    );
  }

  Stream<UserData> getUserDataStream() async* {
    // 模拟异步数据流
    yield UserData(name: 'John Doe', age: 30);
    await Future.delayed(Duration(seconds: 2));
    yield UserData(name: 'Jane Doe', age: 25);
  }
}

class UserData {
  final String name;
  final int age;

  UserData({required this.name, required this.age});

  @override
  String toString() {
    return 'Name: $name, Age: $age';
  }
}

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