如何将来自嵌套的firestore集合的更改接收到单个flutter流中？

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

class NestedCollectionStream extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return StreamBuilder<QuerySnapshot>(
      stream: FirebaseFirestore.instance
          .collection('parentCollection')
          .doc('parentDocument')
          .collection('nestedCollection')
          .snapshots(),
      builder: (BuildContext context, AsyncSnapshot<QuerySnapshot> snapshot) {
        if (snapshot.hasError) {
          return Text('Error: ${snapshot.error}');
        }

        if (snapshot.connectionState == ConnectionState.waiting) {
          return Text('Loading...');
        }

        if (!snapshot.hasData) {
          return Text('No data available');
        }

        // 处理数据
        final List<DocumentSnapshot> documents = snapshot.data.docs;
        // 在这里可以对文档进行处理，如提取字段值等

        return ListView.builder(
          itemCount: documents.length,
          itemBuilder: (BuildContext context, int index) {
            return ListTile(
              title: Text(documents[index].data()['title']),
              subtitle: Text(documents[index].data()['description']),
            );
          },
        );
      },
    );
  }
}