public virtual RedirectToRouteResult RemoveFromCart(Cart cart, int productID, string returnUrl)
        {
            var product = this.repository.GetProducts().FirstOrDefault(x => x.ProductID == productID);

            if (product != null)
            {
                cart.RemoveProduct(product);
            }

            return RedirectToAction(MVC.Cart.Index(cart, returnUrl));
        }