class MessageList extends StatelessWidget {
 MessageList({this.firestore});

 final Firestore firestore;

 @override
 Widget build(BuildContext context) {
 return StreamBuilder<QuerySnapshot>(
  stream: firestore.collection('messages').snapshots(),
  builder: (BuildContext context, AsyncSnapshot<QuerySnapshot> snapshot) {
    if (!snapshot.hasData) return const Text('Loading...');
    final int messageCount = snapshot.data.documents.length;
    return ListView.builder(
      itemCount: messageCount,
      itemBuilder: (_, int index) {
        final DocumentSnapshot document = snapshot.data.documents[index];
        return ListTile(
          title: Text(document['message'] ?? '<No message retrieved>'),
          subtitle: Text('Message ${index + 1} of $messageCount'),
        );
      },
    );
  },
 );
 }
}