public DiscountCalculator(ICanTellDisplayTheTotal totaler, ICanGetSingleItemDeals discountRepository)
 {
     _totaler = totaler;
     _discountRepository = discountRepository;
 }
 public Checkout(ICanTellDisplayTheTotal itemPriceTotaler, DiscountCalculator discountCalculator)
 {
     _itemPriceTotaler = itemPriceTotaler;
     _bob = discountCalculator;
 }