public async Task When_Inner_IFrameworkElement()
        {
            var page = new NativeView_Page();

            TestServices.WindowHelper.WindowContent = page;
            await TestServices.WindowHelper.WaitForIdle();

            // Validates that the templated parent of the native child is the immediate parent's one, not the one from
            // the outer parent.
            var nativeViewIFrameworkElement01 = page.innerFrameworkElement.FindFirstChild <NativeViewIFrameworkElement>();

            Assert.IsNotNull(nativeViewIFrameworkElement01);
            Assert.AreEqual(page.innerFrameworkElement.Tag, nativeViewIFrameworkElement01.MyValue);
        }
        public async Task When_Added_In_Xaml()
        {
            var page = new NativeView_Page();

            TestServices.WindowHelper.WindowContent = page;
            await TestServices.WindowHelper.WaitForIdle();

            var nativeInPanel = page.hostPanel.FindFirstChild <NativeView>();

            Assert.IsNotNull(nativeInPanel);

            var nativeInBorder = page.hostBorder.FindFirstChild <NativeView>();

            Assert.IsNotNull(nativeInBorder);

            var nativeInButton = page.hostButton.FindFirstChild <NativeView>();

            Assert.IsNotNull(nativeInButton);

            var nativeInSplitViewPane = page.hostSplitView.Pane?.FindFirstChild <NativeView>();

            Assert.IsNotNull(nativeInSplitViewPane);

            var nativeInSplitViewContent = page.hostSplitView.Content?.FindFirstChild <NativeView>();

            Assert.IsNotNull(nativeInSplitViewContent);

            page.hostPopup.IsOpen = true;

            await TestServices.WindowHelper.WaitForIdle();

            var nativeInPopup = page.hostPopup.Child?.FindFirstChild <NativeView>();

            Assert.IsNotNull(nativeInPopup);

            page.hostPopup.IsOpen = false;

            await TestServices.WindowHelper.WaitForIdle();

            page.flyoutHostButton.Flyout.ShowAt(page.flyoutHostButton);

            await TestServices.WindowHelper.WaitForIdle();

            var nativeInFlyout = (page.flyoutHostButton.Flyout as Flyout).Content?.FindFirstChild <NativeView>();

            Assert.IsNotNull(nativeInFlyout);
            page.flyoutHostButton.Flyout.Hide();
            TestServices.WindowHelper.WindowContent = null;
        }