private void btnResizeTo_Click(object sender, RoutedEventArgs e)
		{
			var rect = new Rectangle()
			{
				Height = 250,
				Width = 350,
				Fill = new SolidColorBrush(Colors.Blue)
			};
			MainStage.Children.Add(rect);
			rect.SetPosition(50, 50);

			rect.ResizeTo(150, 150, 1.5.seconds())
				.WhenComplete(a =>
				{
					Thread.Sleep(2000);
					MainStage.Children.Remove(rect);
				})
				.Begin();
		}