public bool AddFlight(FlightModel flight)
        {
            List <FlightModel> flightData = FlightDataInitialization.FlightData(flight.GateID);

            flightData.Add(flight);
            return(true);
        }
        public IEnumerable <FlightModel> GetAllFlights()
        {
            List <GateModel> gateModelData = GatesDataInitialization.GatesData();

            List <FlightModel> flightData = FlightDataInitialization.FlightData(gateModelData.First().GateID);

            flightData.AddRange(FlightDataInitialization.FlightData(gateModelData.Last().GateID));
            return(flightData.AsEnumerable <FlightModel>());
        }