public void ShouldSetPosition() { var element = new Placeholder(); var canvas = new Canvas(); canvas.Children.Add(element); canvas.GetChildPosition(element).ShouldBe(new Point(0,0)); canvas.SetPosition(element, 10, 5); canvas.GetChildPosition(element).ShouldBe(new Point(10, 5)); canvas.SetPosition(element, new Point(20, 40)); canvas.GetChildPosition(element).ShouldBe(new Point(20, 40)); }