public ValidationResult PlaceABid(string bidderName, string roomId, decimal bidAmount)
        {
            var guid = new Guid(roomId);
            var room = _roomService.Get(guid);

            var bidder = _buyerService.FindByName(bidderName).First();

            var bid = new Bid(room, bidder, bidAmount, BidType.Online);

            BeginTransaction();

            ValidationResult = !room.TryPlaceBid(bid)
                ? ValidationExtensions.ToValidationResult(room.ValidationErrors).ToViewModel()
                : _roomService.Update(room).ToViewModel();

            if (ValidationResult.IsValid)
            {
                Commit();
            }

            return(ValidationResult);
        }
        public IEnumerable <Buyer> FindByName(string name)
        {
            var buyersModel = _buyerService.FindByName(name);

            return(buyersModel.Select(buyer => buyer.ToViewModel()));
        }