public async Task EnsuresNonNullArguments()
            {
                var gitHubClient = Substitute.For <IGitHubClient>();
                var client       = new ObservableProjectColumnsClient(gitHubClient);

                await Assert.ThrowsAsync <ArgumentNullException>(() => client.GetAll(1, null).ToTask());
            }
            public void RequestCorrectURL()
            {
                var connection   = Substitute.For <IConnection>();
                var gitHubClient = new GitHubClient(connection);
                var client       = new ObservableProjectColumnsClient(gitHubClient);

                client.GetAll(1);

                connection.Received().Get <List <ProjectColumn> >(
                    Arg.Is <Uri>(u => u.ToString() == "projects/1/columns"),
                    Args.EmptyDictionary,
                    "application/vnd.github.inertia-preview+json");
            }