public CurrentConditionsDisplay(ISubject subject)
 {
     subject.RegisterObserver(this);
     temperatureMonitor = (ITemperatureMonitor)subject;
     humidityMonitor    = (IHumidityMonitor)subject;
 }
 public ForecastDisplay(ISubject subject)
 {
     subject.RegisterObserver(this);
     humidityMonitor = (IHumidityMonitor)subject;
     pressureMonitor = (IPressureMonitor)subject;
 }