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

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

                Assert.Throws <ArgumentException>(() => client.Get("", "name"));
                Assert.Throws <ArgumentException>(() => client.Get("owner", ""));
            }
            public void RequestsCorrectUrlWithRepositoryId()
            {
                var gitHubClient = Substitute.For <IGitHubClient>();
                var client       = new ObservableRepositoryPagesClient(gitHubClient);

                client.Get(1);

                gitHubClient.Received().Repository.Page.Get(1);
            }