public async Task <ActionResult <long> > InsertAttendees(AttendeeRegistrationRequestDto item)
        {
            var insertedSequence = await attendeeRepository.InsertAsync(item.AsAttnedee());

            if (insertedSequence < 1)
            {
                return(StatusCode(StatusCodes.Status406NotAcceptable));
            }
            return(StatusCode(StatusCodes.Status201Created, insertedSequence));
        }