public async Task should_save_refresh_token_and_return_repositorys_token()
        {
            // given
            string expectedToken = "refresh";
            string email         = "*****@*****.**";
            string ipAddress     = "127.1.2.3";

            _refreshTokenRepository.AddRefreshToken(email, Arg.Any <string>(), ipAddress)
            .Returns(new UserRefreshToken()
            {
                RefreshToken = expectedToken
            });

            // when
            string token = await _service.CreateRefreshToken(email, ipAddress);

            // then
            token.ShouldBe(expectedToken);
        }