private void Initialize()
 {
     if (!_isInitialized)
     {
         _resolution        = new Resolution(Screen.width, Screen.height);
         _currentResolution = new BehaviorSubject <Resolution>(_resolution);
         _isInitialized     = true;
     }
 }
        void Update()
        {
            var currentResolution = new Resolution(Screen.width, Screen.height);

            if (currentResolution != _resolution)
            {
                _resolution = currentResolution;

                if (OnResolutionChanged != null)
                {
                    OnResolutionChanged(_resolution);
                }
                _currentResolution.OnNext(_resolution);
            }
        }