anchor.diff:        }
       }
   
  -    reply.send(squares);
  +    return squares;
     });
   }
  
positive.code:   final demo = new QrDemo(canvas);
  
    final InputElement input = query('#input');
    input.value = "Type your message in here...";
    demo.updateValue(input.value);
  
    input.on.keyUp.add((KeyboardEvent args) {
      demo.updateValue(input.value);
    });
  }
  
  class QrDemo{
    static final int errorCorrectLevel = core.QrErrorCorrectLevel.M;
    static final int typeNumber = 10;
    static final int size = typeNumber * 4 + 17;
  
    final CanvasElement _canvas;
    final core.SendPortValue<String, List<bool>> _qrMapper;
    final int scale;
    final int offset;
  
  
negative.code:   }
  }
  
  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;
  
    new core.SendValuePort<String, List<bool>>((String input){
      final code = new core.QrCode(typeNumber, errorCorrectLevel);
      code.addData(input);
      code.make();
  