public void TestFindSourceById()
        {
            using (var context = new MainContext()) {
                var source      = Idle.CreateSource();
                var id          = source.Attach(context);
                var foundSource = context.FindSourceById(id);
                Assert.That(foundSource.Handle, Is.EqualTo(source.Handle));
            }

            Utility.AssertNoGLibLog();
        }