如何结合使用flutter_typeahead和FirestoreFirebase来生成建议？

import 'package:flutter_typeahead/flutter_typeahead.dart';
import 'package:cloud_firestore/cloud_firestore.dart';

TypeAheadFormField(
  textFieldConfiguration: TextFieldConfiguration(
    // 设置文本输入框的样式和属性
    decoration: InputDecoration(
      labelText: '搜索',
      hintText: '输入关键词',
      prefixIcon: Icon(Icons.search),
    ),
  ),
  suggestionsCallback: (pattern) async {
    // 在Firestore中查询匹配的建议
    QuerySnapshot querySnapshot = await FirebaseFirestore.instance
        .collection('suggestions')
        .where('keyword', isGreaterThanOrEqualTo: pattern)
        .where('keyword', isLessThanOrEqualTo: pattern + '\uf8ff')
        .get();
    return querySnapshot.docs
        .map((doc) => doc.data()['keyword'])
        .toList();
  },
  itemBuilder: (context, suggestion) {
    // 构建建议列表项的UI
    return ListTile(
      title: Text(suggestion),
    );
  },
  onSuggestionSelected: (suggestion) {
    // 处理用户选择的建议
    print('Selected suggestion: $suggestion');
  },
)