anchor.diff:      });
     }
   
  -  bool get _isComposing => _currentMessage == null || _currentMessage.length == null > 0;
  +  bool get _isComposing => _currentMessage.length > 0;
   
     Widget _buildTextComposer() {
       return new Column(
  
positive.code:       'text': text,
      };
      _firebase.push().set(message);
      setState(() {
        _currentMessage = null;
        _messageKey.currentState.setText('');
      });
    }
  
    Widget _buildMessage(int index) {
  
negative.code:   void initState() {
      _firebase = new Firebase("https://firechat-flutter.firebaseio.com/");
      _user = "Guest${new math.Random().nextInt(1000)}";
      _currentMessage = '';
      _firebase.onChildAdded.listen((Event event) {
        Map<String, String> message = event.snapshot.val();
        setState(() => _messages.add(message));
  