public void SetUp()
 {
     _mockFlightRepository = new Mock<IRepository<Flight>>();
     _mockAirportRepository = new Mock<IRepository<Airport>>();
     _mockAirportFlightRepository = new Mock<IRepository<AirportFlight>>();
     _mockTicketOfficeRepository = new Mock<IRepository<TicketOffice>>();
     service = new FlightReservationService(_mockAirportRepository.Object, _mockFlightRepository.Object, _mockAirportFlightRepository.Object, _mockTicketOfficeRepository.Object);
 }