Agathas.Storefront.Shopping.Model.Baskets.NonNegativeQuantity.is_zero C# (CSharp) Method

        public bool is_zero()
        {
            return _value == 0;
        }

        public void change_quantity_of_product(NonNegativeQuantity quantity, ProductSnapshot product_snapshot, IBasketPricingService basket_pricing_service)
        {
            // TODO: Check for null values and invalid data

            if (basket_contains_an_item_for(product_snapshot))
            {
                if (quantity.is_zero())
                {
                    remove_product_with_id_of(product_snapshot, basket_pricing_service);
                }
                else
                    get_item_for(product_snapshot).change_item_quantity_to(quantity);

                recalculate_basket_totals(basket_pricing_service);
            }
        }