public async Task <ActionResult <List <Flight> > > GetFlightsByDestinationCountry(int country_id)
        {
            FlightsCenterSystem.GetInstance().login(GetLoginToken().Name, GetLoginToken().Password,
                                                    out LoginToken <Object> l, out FacadeBase f);
            facade = f as LoggedInCustomerFacade;
            var result = await Task.Run(() => facade.GetFlightsByDestinationCountry(country_id));

            return(StatusCode(200, result));
        }