anchor.diff:    final String owner;
     final List<String> receivers;
     final String text;
  -  
  +
     Message(this.owner, this.receivers, this.text);
     
     toString() => 'from $owner, to $receivers: $text';
  
positive.code:     
      var enter$ = _input.keyboard$
            .where((e) => e.keyCode == KeyCode.ENTER && e.target.value != '');
      
  
      lifeCycle$.where((e) => e is WillMountEvent).listen((onData) {
        globalEvent$.listen((m) {
          messages.add(m);
  
negative.code:     return 
      div(className: 'panel panel-primary', children: [
        div(className: 'panel-heading', children: receivers.join(', ')),
        span(className:'glyphicon glyphicon-pencil', children: '$_typingString'),
        _body,
        _input
      ]);
  