private static decimal GetTotalPrice(ProductInBasket productInBasket)
{
return(productInBasket.Price * productInBasket.Quantity);
}
internal static decimal GetTotalDiscount(ProductInBasket productInBasket)
{
List <decimal> discountedItems = productInBasket.Discounts.Select(discount => discount.GetDiscount(productInBasket)).ToList();
return(discountedItems.Sum());
}