module observer.app; import observer.weatherdata; import observer.currentconditionsdisplay; import observer.heatindexdisplay; void main() { WeatherData weatherData = new WeatherData(); CurrentConditionsDisplay currentDisplay = new CurrentConditionsDisplay(weatherData); HeatIndexDisplay heatIndexDisplay = new HeatIndexDisplay(weatherData); weatherData.setMeasurements(80, 65, 30.4f); weatherData.setMeasurements(82, 70, 29.2f); weatherData.removeObserver(heatIndexDisplay); weatherData.setMeasurements(78, 90, 29.2f); weatherData.setMeasurements(81, 72, 29.5f); }