public static BluePrintDto CreateBluePrint(BluePrintRequestDtos.BluePrintAdd createDto) { using (var uow = new BlueprintUnitOfWork()) { var user = uow.Users.Find(createDto.UserId); if (user == null || user.BluePrints.FirstOrDefault(b => b.Name == createDto.BluePrintName) != null) { return null; } var bp = createDto.ToEntity(); user.BluePrints.Add(bp); uow.Save(); return bp.ToDto(); } }