public void RequestsCorrectUrl()
            {
                var gitHubClient = Substitute.For<IGitHubClient>();
                var client = new ObservableCommitStatusClient(gitHubClient);

                client.GetCombined("fake", "repo", "sha");

                gitHubClient.Received().Repository.Status.GetCombined("fake", "repo", "sha");
            }
            public void EnsuresNonNullArguments()
            {
                var client = new ObservableCommitStatusClient(Substitute.For<IGitHubClient>());

                Assert.Throws<ArgumentNullException>(() => client.GetCombined(null, "name", "sha"));
                Assert.Throws<ArgumentNullException>(() => client.GetCombined("owner", null, "sha"));
                Assert.Throws<ArgumentNullException>(() => client.GetCombined("owner", "name", null));

                Assert.Throws<ArgumentNullException>(() => client.GetCombined(1, null));

                Assert.Throws<ArgumentException>(() => client.GetCombined("", "name", "sha"));
                Assert.Throws<ArgumentException>(() => client.GetCombined("owner", "", "sha"));
                Assert.Throws<ArgumentException>(() => client.GetCombined("owner", "name", ""));

                Assert.Throws<ArgumentException>(() => client.GetCombined(1, ""));
            }