public void GetTokenUserId()
        {
            NancyWebAppConfig.IdentityServerEnabled = true;
            var    server  = new TestServer(new WebHostBuilder().UseStartup(typeof(Startup)));
            var    handler = server.CreateHandler();
            var    client  = new BasicClient(handler, "https://server/connect/token", "client", "secret");
            string userId  = null;

            this.Invoking((a) =>
            {
                //  act
                client.AuthenticateUserAsync("alfredorevilla", "password", "api1").RunAsSynchronous();
                userId = client.GetTokenUserId();
            })

            //  assert
            .ShouldNotThrow();
            userId.Should().Be("F7D5AC0B-5C00-4253-8B54-046392260658");
        }