private void QuoteBestPrice(QuotationFulfillment quotationFulfillment)
 {
     FulfilledPriceQuotes.Where(x => x.Id == quotationFulfillment.Id).ToList().ForEach(x =>
     {
         quotationFulfillment.Requester.Tell(BestPriceQuotationFrom(quotationFulfillment));
         FulfilledPriceQuotes.Remove(x);
     });
 }
            private BestPriceQuotation BestPriceQuotationFrom(QuotationFulfillment quotationFulfillment)
            {
                var bestPrices = quotationFulfillment
                                 .PriceQuotes.GroupBy(x => x.ItemId)
                                 .Select(x => new { x.Key, BestPrice = x.OrderByDescending(t => t.DiscountPrice).First() })
                                 .Select(x => x.BestPrice).ToList();

                return(new BestPriceQuotation(quotationFulfillment.Id, bestPrices));
            }