public void RemoveFromEvent(long donorId,
                                    long eventId,
                                    ref IAuctionTransaction trans)
        {
            using (var records = new AuctionEventDonorCollection())
            {
                var filter = new PredicateExpression { AuctionEventDonorFields.DonorId == donorId };
                filter.AddWithAnd(AuctionEventDonorFields.EventId == eventId);

                records.DeleteMulti(filter);
            }
        }
 public void RemoveFromAllEvents(long donorId,
                                 ref IAuctionTransaction trans)
 {
     using(var records = new AuctionEventDonorCollection())
     {
         var filter = new PredicateExpression {AuctionEventDonorFields.DonorId == donorId};
         records.DeleteMulti(filter);
     }
 }