anchor.diff:  
     void stop() {
       _stop = true;
  +    _pauseStreamController.close();
     }
   
     bool get isStopped => _stop;
  
positive.code:   void resume() {
      if (!_stop && _pause) {
        _pause = false;
        _startGameLoops();
      }
    }
  
negative.code:   void pause() {
      if (!_stop) {
        _pause = true;
        _pauseStreamController.add(true);
      }
    }
  
    Stream<bool> onPause() {
      return _pauseStreamController.stream;
    }
  
    bool get paused => _pause;
  