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

                client.Delete(1, "heads/develop");

                gitHubClient.Received().Git.Reference.Delete(1, "heads/develop");
            }
            public void EnsuresNonNullArguments()
            {
                var client = new ObservableReferencesClient(Substitute.For<IGitHubClient>());

                Assert.Throws<ArgumentNullException>(() => client.Delete(null, "name", "heads/develop"));
                Assert.Throws<ArgumentNullException>(() => client.Delete("owner", null, "heads/develop"));
                Assert.Throws<ArgumentNullException>(() => client.Delete("owner", "name", null));

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

                Assert.Throws<ArgumentException>(() => client.Delete("", "name", "heads/develop"));
                Assert.Throws<ArgumentException>(() => client.Delete("owner", "", "heads/develop"));
                Assert.Throws<ArgumentException>(() => client.Delete("owner", "name", ""));

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