public void Focus_Should_Set_FocusManager_Current()
        {
            Button target;

            using (UnitTestApplication.Start(TestServices.RealFocus))
            {
                var root = new TestRoot
                {
                    Child = target = new Button()
                };

                target.Focus();

                Assert.Same(target, FocusManager.Instance.Current);
            }
        }
        public void Focus_Should_Be_Cleared_When_Control_Is_Removed_From_VisualTree()
        {
            Button target;

            using (UnitTestApplication.Start(TestServices.RealFocus))
            {
                var root = new TestRoot
                {
                    Child = target = new Button()
                };

                target.Focus();
                root.Child = null;

                Assert.Null(FocusManager.Instance.Current);
            }
        }