public void Execute(Player player)
        {
            if (!_isPlayerNameUniqueQuery.Execute(player.Name))
            {
                throw new AlreadyExistsException("Player name not unique");
            }

            _addCommand.Execute(player);
        }
        public ActionResult Create(Player player)
        {
            try
            {
                _addPlayerCommand.Execute(player);
            }
            catch (AlreadyExistsException exception)
            {
                ModelState.AddModelError("_FORM", exception.Message);
                return View("New");
            }

            return RedirectToAction("Index", "PlayerSelection");
        }