public void Index_Action_Renders_Default_View_With_Cart_And_ReturnUrl()
 {
     // Подготовка
     Cart cart = new Cart();
     CartController controller = new CartController(null,null);
     // Действие
     ViewResult result = controller.Index(cart, "myReturnUrl");
     // Утверждение
     Assert.IsEmpty(result.ViewName);
     Assert.AreSame(cart, result.ViewData.Model);
     Assert.AreEqual("myReturnUrl", result.ViewData["returnUrl"]);
     Assert.AreEqual("Cart", result.ViewData["CurrentCategory"]);
 }