public ActionResult Pay(string errorMessage = null)
        {
            _wca.GetContext().Layout.IsCartPage = true;
            var checkoutData = GetCheckoutData();

            if ((checkoutData.CheckoutItems == null || !checkoutData.CheckoutItems.Any()) && checkoutData.Amount <= 0)
            {
                return(RedirectToAction("Index", "ShoppingCart"));
            }
            checkoutData.PublishableKey = _stripeService.GetSettings().PublishableKey;
            if (!String.IsNullOrEmpty(errorMessage))
            {
                _notifier.Error(new LocalizedString(errorMessage));
            }
            return(View(checkoutData));
        }