public void GivenSomeState_RedirectToAuthenticate_ReturnsAUri()
            {
                // Arrange.
                var googleProvider = new GoogleProvider(new ProviderParams {
                    Key = "aa", Secret = "bb"
                });

                // Act.
                var result =
                    googleProvider.RedirectToAuthenticate(new GoogleAuthenticationServiceSettings
                {
                    State       = "bleh",
                    CallBackUri = new Uri("http://2p1s.com")
                });

                // Assert.
                Assert.NotNull(result);
                Assert.Equal(
                    "https://accounts.google.com/o/oauth2/auth?client_id=aa&redirect_uri=http://2p1s.com/&response_type=code&scope=https://www.googleapis.com/auth/userinfo.profile%20https://www.googleapis.com/auth/userinfo.email&state=bleh",
                    result.AbsoluteUri);
            }