public async Task EnsuresNonNullArguments()
            {
                var client  = new ProjectCardsClient(Substitute.For <IApiConnection>());
                var newCard = new NewProjectCard("someNote");

                await Assert.ThrowsAsync <ArgumentNullException>(() => client.Create(1, null));
            }
            public async Task PostsToCorrectURL()
            {
                var connection = Substitute.For <IApiConnection>();
                var client     = new ProjectCardsClient(connection);
                var newCard    = new NewProjectCard("someNote");

                await client.Create(1, newCard);

                connection.Received().Post <ProjectCard>(
                    Arg.Is <Uri>(u => u.ToString() == "projects/columns/1/cards"),
                    newCard,
                    "application/vnd.github.inertia-preview+json");
            }