public async Task EnsuresNonNullArguments()
            {
                var client = new ObservableRepositoryBranchesClient(Substitute.For<IGitHubClient>());
                var contextsToRemove = new List<string>() { "test" };

                Assert.Throws<ArgumentNullException>(() => client.DeleteRequiredStatusChecksContexts(null, "repo", "branch", contextsToRemove));
                Assert.Throws<ArgumentNullException>(() => client.DeleteRequiredStatusChecksContexts("owner", null, "branch", contextsToRemove));
                Assert.Throws<ArgumentNullException>(() => client.DeleteRequiredStatusChecksContexts("owner", "repo", null, contextsToRemove));
                Assert.Throws<ArgumentNullException>(() => client.DeleteRequiredStatusChecksContexts("owner", "repo", "branch", null));

                Assert.Throws<ArgumentNullException>(() => client.DeleteRequiredStatusChecksContexts(1, null, contextsToRemove));
                Assert.Throws<ArgumentNullException>(() => client.DeleteRequiredStatusChecksContexts(1, "branch", null));

                Assert.Throws<ArgumentException>(() => client.DeleteRequiredStatusChecksContexts("", "repo", "branch", contextsToRemove));
                Assert.Throws<ArgumentException>(() => client.DeleteRequiredStatusChecksContexts("owner", "", "branch", contextsToRemove));
                Assert.Throws<ArgumentException>(() => client.DeleteRequiredStatusChecksContexts("owner", "repo", "", contextsToRemove));

                Assert.Throws<ArgumentException>(() => client.DeleteRequiredStatusChecksContexts(1, "", contextsToRemove));
            }
            public void RequestsTheCorrectUrlWithRepositoryId()
            {
                var gitHubClient = Substitute.For<IGitHubClient>();
                var client = new ObservableRepositoryBranchesClient(gitHubClient);
                var contextsToRemove = new List<string>() { "test" };

                client.DeleteRequiredStatusChecksContexts(1, "branch", contextsToRemove);

                gitHubClient.Repository.Branch.Received()
                    .DeleteRequiredStatusChecksContexts(1, "branch", contextsToRemove);
            }