public void GetsStarsForUser()
            {
                var connection = Substitute.For<IConnection>();
                var gitHubClient = Substitute.For<IGitHubClient>();
                gitHubClient.Connection.Returns(connection);
                var client = new ObservableStarredClient(gitHubClient);

                client.GetAllForUser("jugglingnutcase");
                connection.Received().GetAsync<List<Repository>>(ApiUrls.StarredByUser("jugglingnutcase"), null, null);
            }
            public async Task EnsuresArguments()
            {
                var client = new ObservableStarredClient(Substitute.For<IGitHubClient>());

                await AssertEx.Throws<ArgumentException>(async () => await client.GetAllForUser(null));
            }