private void Setup_Factory()
        {
            mockFactory = Substitute.For <IAirTrafficMonitorFactory>();

            /*
             * Commented these out. Factory has private setter now /Frank
             *
             * mockFactory.Airspace = Substitute.For<IAirspace>();
             * mockFactory.AirspaceService = Substitute.For<IAirspaceService>();
             * mockFactory.SeparationService = Substitute.For<ISeparationService>();
             * mockFactory.TrackingService = Substitute.For<ITrackingService>();*/
        }
        public AirTrafficMonitor(IAirTrafficMonitorFactory factory, ITransponderReceiver receiver)
        {
            _separationService = factory.SeparationService;
            _trackingService   = factory.TrackingService;
            _airspaceService   = factory.AirspaceService;
            _airspace          = factory.Airspace;

            //Subscribe to events.
            receiver.TransponderDataReady += TransponderReceiver_DataReady;

            //Initialize
            _trackings        = new HashSet <ITrack>();
            _separationEvents = new HashSet <ISeparationEvent>();
        }