public void UserSuppliedDispatcher()
        {
            Assert.Throws <ArgumentNullException> (delegate {
                new DispatcherSynchronizationContext(null);
            }, ".ctor(null)");

            Dispatcher d = Application.Current.RootVisual.Dispatcher;
            DispatcherSynchronizationContext dsc = new DispatcherSynchronizationContext(d);

            Assert.AreNotSame(dsc, dsc.CreateCopy(), "CreateCopy");
        }
        public void Default()
        {
            DispatcherSynchronizationContext dsc = new DispatcherSynchronizationContext();

            Assert.AreNotSame(dsc, dsc.CreateCopy(), "CreateCopy");
        }