public async Task EnsuresNonNullArguments()
            {
                var client = new ObservableRepositoryBranchesClient(Substitute.For<IGitHubClient>());
                var update = new BranchProtectionSettingsUpdate(
                    new BranchProtectionRequiredStatusChecksUpdate(true, true, new[] { "test" }));

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

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

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

                Assert.Throws<ArgumentException>(() => client.UpdateBranchProtection(1, "", update));
            }
            public void RequestsTheCorrectUrlWithRepositoryId()
            {
                var gitHubClient = Substitute.For<IGitHubClient>();
                var client = new ObservableRepositoryBranchesClient(gitHubClient);
                var update = new BranchProtectionSettingsUpdate(
                    new BranchProtectionRequiredStatusChecksUpdate(true, true, new[] { "test" }));

                client.UpdateBranchProtection(1, "branch", update);

                gitHubClient.Repository.Branch.Received()
                    .UpdateBranchProtection(1, "branch", update);
            }