public void CreateRoleForUser(User user, string role) { if (user == null) { throw new ArgumentNullException("user"); } if (role == null) { throw new ArgumentNullException("role"); } UpdateResult updateResult = _userRoleRepository.CreateRoleForUser(user, role); switch (updateResult) { case UpdateResult.Stalled: throw new StaleUserException(string.Format(CultureInfo.InvariantCulture, "Error creating user role for user with email {0}, object stalled", user.Email)); case UpdateResult.ItemNotExists: throw new UserNotExistsException(string.Format(CultureInfo.InvariantCulture, "Error creating user role for user with email {0}, user not found", user.Email)); } }