anchor.diff:    }
   }
   
  +class _QrCalc extends core.SendPortValue<String, List<bool>> {
  +  _QrCalc() : super(spawnFunction(_qrIsolate));
  +}
   
   void _qrIsolate() {
     final errorCorrectLevel = QrDemo.errorCorrectLevel;
     final typeNumber = QrDemo.typeNumber;
     final size = QrDemo.size;
   
  -  port.receive((String input,
  -      SendPort reply) {
  -
  +  new core.SendValuePort<String, List<bool>>((String input){
       final code = new core.QrCode(typeNumber, errorCorrectLevel);
       code.addData(input);
       code.make();
  
positive.code:     _canvas.on.mouseMove.add(_canvas_mouseMove);
      _canvas.on.mouseOut.add(_canvas_mouseOut);
    }
  
    void updateValue(String value) {
      _qrMapper.input = value;
  
negative.code:       }
      }
  
      return squares;
    });
  }
  