public override void Execute()
{
var temperatureSensor = new TemperatureSensor();
var heater = new Heater(temperatureSensor, maxHeatingTemperature: 18); // 64° F
var airConditioner = new AirConditioner(temperatureSensor, minCoolingTemperature: 21); // 70° F
temperatureSensor.Temperature = 17; // 62° F
Assert.True(heater.IsHeating);
Assert.False(airConditioner.IsCooling);
temperatureSensor.Temperature = 20; // 68° F
Assert.False(heater.IsHeating);
Assert.False(airConditioner.IsCooling);
temperatureSensor.Temperature = 22; // 72° F
Assert.False(heater.IsHeating);
Assert.True(airConditioner.IsCooling);
temperatureSensor.RemoveListener(heater);
temperatureSensor.Temperature = 17; // 62° F
Assert.False(heater.IsHeating);
Assert.False(airConditioner.IsCooling);
// heater is no longer subscribed, so it wasn't notified of the temperature changes.
}
