anchor.diff:    CanvasGradient _gradient;
     static const int FADE_IN_MILLISECONDS = 500;
     
  +  final ImageElement _successSource = 
  +      new ImageElement(src: "packages/slot_machine/img/slot-success.gif", 
  +          width: 40, height: 40);
  +  final ImageElement _failureSource = 
  +      new ImageElement(src: "packages/slot_machine/img/slot-failure.gif", 
  +          width: 40, height: 40);
  +  
     SpanElement resultEl;
     
     List<_SlotMachineLine> _lines;
  
positive.code:     }
      _rollCompleter = new Completer<String>();
      
      update(0);
      
      return _rollCompleter.future;
    }
  
negative.code:     _lines = new List<_SlotMachineLine>(slotLines);
      for (int i = 0; i < slotLines; i += 1) {
        _lines[i] = new _SlotMachineLine(linesProbabilities[i], _ctx, i * width,
            width, height, _successSource, _failureSource);
      }
      currentResults = new List<bool>(slotLines);
      
  