anchor.diff:    }
     
     num last_t = 0;
  -  num _timeFromStartOfRoll;
  +  num _timeOfStartOfRoll;
     List<bool> currentResults;
     
     void update(num timeFromStartOfPage) {
  -    if (_timeFromStartOfRoll == null && timeFromStartOfPage != 0) {
  -      _timeFromStartOfRoll = timeFromStartOfPage;
  +    if (_timeOfStartOfRoll == null && timeFromStartOfPage != 0) {
  +      _timeOfStartOfRoll = timeFromStartOfPage;
       }
       num dt = timeFromStartOfPage - last_t;
       last_t = timeFromStartOfPage;
  
positive.code:     // Draw the gradient overlay.
      _ctx.fillStyle = _gradient;
      _ctx.fillRect(0, 0, width * slotLines, height * 3);
      
      resultEl.text = currentResultText;
      
  
negative.code:     for (int i = 0; i < slotLines; i++) {
        _SlotMachineLine line = _lines[i];
        currentResults[i] = line.currentResult;
        if (_timeOfStartOfRoll != null &&
            last_t - _timeOfStartOfRoll > line.fullSpeedMilliseconds) {
          line.isSlowingDown = true;
        }
        line.update(dt);
  