Наследование: TaggedEntity, IAttendee
 public ActionResult Create(Attendee attendee)
 {
     _attendeeRepository.Insert(attendee);
     return RedirectToAction("Index");
 }
 public HttpResponseMessage<Attendee> Post(Attendee attendee, HttpRequestMessage<Attendee> request)
 {
     _attendeeRepository.Insert(attendee);
     attendee = _attendeeRepository.Get(attendee.Id) as Attendee;
     return new HttpResponseMessage<Attendee>(attendee, HttpStatusCode.Created);
 }