public void AddingCrew()
        {
            MSSQLContext           context         = new MSSQLContext();
            CrewsRepository        crewsRepository = new CrewsRepository();
            PilotsRepository       pRepository     = new PilotsRepository();
            StewardessesRepository sRepository     = new StewardessesRepository();
            CrewingUnitOfWork      uow             = new CrewingUnitOfWork(crewsRepository, pRepository, sRepository, context);

            var crew = uow.Crews.Update(new Crew()
            {
                Pilot        = pRepository.Get(1),
                Stewardesses = sRepository.GetAll().Take(3).ToList()
            });

            uow.SaveChanges();
            crewId = crew.Id;
        }