public void InsertBid(Bid Bid) { if (Bid == null) { throw new ArgumentNullException("Bid"); } var auction = _auctionService.GetAuctionById(Bid.AuctionId); if (Bid.Amount > _auctionService.GetHighestBidForAuction(auction).Amount) { _bidService.InsertBid(Bid); } else { throw new Exception("Bid amount too low."); } _eventPublisher.EntityInserted(Bid); }