static void Main(string[] args) { /*create an airport which has 3 people plane, * 2 cargo plane and 1 space plane*/ var airport1 = new Airport("Eindhoven"); //list all the airplanes of the airport airport1.ShowAirplanes(); //request airplanes and take some actions with them try { PeoplePlane airplane1 = (PeoplePlane)airport1.RequestPlane("ABC124"); airplane1.Load(133); airplane1.TakeOff(); airplane1.Load(5); airplane1.Land(); airplane1.Unload(); airport1.ShowAvailableAirplanes(); } catch (NullReferenceException ex) { Console.WriteLine(ex); } try { CargoPlane airplane2 = (CargoPlane)airport1.RequestPlane("FF2134"); airplane2.Load(25); airplane2.TakeOff(); airplane2.Unload(); airplane2.Land(); airplane2.Unload(); } catch (NullReferenceException ex) { Console.WriteLine(ex); } try { SpacePlane spaceAirplane = (SpacePlane)airport1.RequestPlane("SPC777"); spaceAirplane.StartMotor(); spaceAirplane.TakeOff(); spaceAirplane.TakeOverMissile(5); } catch (NullReferenceException ex) { Console.WriteLine(ex); } }