public BindablePageTests()
        {
            _navigationService = new Win81TestNavigationService();

            CoreServiceLocator.UnRegisterService<INavigationService>();
            CoreServiceLocator.RegisterService<INavigationService>(() => _navigationService);
        }
        public async Task TestInit()
        {
            _navigationService = new Win81TestNavigationService();

            await ExecuteOnUIThreadAsync(() =>
            {
                Window.Current.Content = new Frame() { CacheSize = 1 };
            });
        }