public async Task PostsToCorrectURL()
            {
                var connection = Substitute.For <IApiConnection>();
                var client     = new ProjectCardsClient(connection);
                var position   = new ProjectCardMove(ProjectCardPosition.Top, 1, null);

                await client.Move(1, position);

                connection.Connection.Received().Post(
                    Arg.Is <Uri>(u => u.ToString() == "projects/columns/cards/1/moves"),
                    position,
                    "application/vnd.github.inertia-preview+json");
            }
            public async Task EnsuresNonNullArguments()
            {
                var client = new ProjectCardsClient(Substitute.For <IApiConnection>());

                await Assert.ThrowsAsync <ArgumentNullException>(() => client.Move(1, null));
            }