private void CloseScreen(ScreenController screen, IUIAnimation animation = null)
    {
        _navigationStack.Remove(screen);

        if (animation == null)
        {
            GameObject.Destroy(screen.gameObject);
            return;
        }

        animation.AnimateOn(screen.GetComponent <RectTransform>())
        .Then(() => GameObject.Destroy(screen.gameObject));
    }