anchor.diff:      };
     }
   
  +  // TODO rename sendString
  +  // TODO send with List<int> 
     void send(String data){
       // TODO check OPEN
       _state = CLOSING;
  
positive.code:     return controller.stream;
    }
  
    Stream<bool> get onClose {
      StreamController<bool> controller = new StreamController();
      _closeControllers.add(controller);
  
negative.code:     _openAsync(portname, baudrate);
    }
  
    // TODO un Future
    Stream<bool> get onOpen {
      StreamController<bool> controller = new StreamController();
      _openControllers.add(controller);
  