public void ListBox_ItemCopiedToDataContext3 ()
		{
			bool realized;
			ListBox box = new ListBox ();
			box.ItemsPanel = CreateVirtualizingPanel ();
			CreateAsyncTest (box,
				() => {
					box.Items.Add (new Rectangle ());
				}, () => {
					ListBoxItem container;
					var panel = box.FindFirstChild<CustomVirtualizingPanel> ();
					using (panel.ItemContainerGenerator.StartAt (new GeneratorPosition (-1, 1), GeneratorDirection.Forward, true))
						container = (ListBoxItem) panel.ItemContainerGenerator.GenerateNext (out realized);
					Assert.IsNotNull (container, "#1");
					IGenerator.PrepareItemContainer (container);
					Assert.AreEqual (box.Items [0], container.Content, "#2");
				}
			);
		}