[AverageDisplay|- sum:float;- count:int|update();display()]
[Observer]^-.-[AverageDisplay]
[MainDriver||main()]
[NumericDisplay|- value:int|update();display()]
[Observer]^-.-[NumericDisplay]
[Observer||update()]
[Subject||attach();detach();notifyObservers()]
[TemperatureSensor|- observers:ArrayList of Observer;- tempState:int|attach();detach();setTemp();notifyObservers();getTemp()]
[TemperatureSensor]->[Observer]
[Subject]^-.-[TemperatureSensor]
[TextDisplay|- value:int|update();display()]
[Observer]^-.-[TextDisplay]