static void Main(string[] args)
{
Thermostat thermostat = new Thermostat();
Heater heater = new Heater(30);
Cooler cooler = new Cooler(40);
thermostat.Register(heater);
thermostat.Register(cooler);
thermostat.EmulateTemperatureChange();
thermostat.Unregister(cooler);
thermostat.EmulateTemperatureChange();
Console.ReadKey();
}