/// <summary>
        /// Adds to shopping cart.
        /// </summary>
        /// <param name="productCode">The product code.</param>
        /// <param name="quantity">The quantity.</param>
        public static void AddToShoppingCart(string productCode, string quantity)
        {
            Assert.ArgumentNotNullOrEmpty(productCode, "productCode");
            Assert.ArgumentNotNullOrEmpty(quantity, "quantity");

            IShoppingCartManager shoppingCartManager = Context.Entity.Resolve <IShoppingCartManager>();

            uint q;

            if (string.IsNullOrEmpty(quantity) || !uint.TryParse(quantity, out q))
            {
                shoppingCartManager.AddProduct(productCode, 1);
            }
            else
            {
                shoppingCartManager.AddProduct(productCode, q);
            }

            ShoppingCart     shoppingCart             = Context.Entity.GetInstance <ShoppingCart>();
            ShoppingCartLine existingShoppingCartLine = shoppingCart.ShoppingCartLines.FirstOrDefault(p => p.Product.Code.Equals(productCode));

            try
            {
                Tracker.StartTracking();
                AnalyticsUtil.AddToShoppingCart(existingShoppingCartLine.Product.Code, existingShoppingCartLine.Product.Title, 1, existingShoppingCartLine.Totals.PriceExVat);
            }
            catch (Exception ex)
            {
                LogException(ex);
            }
        }