Developers guide

109
if( listener instanceof MasterswitchListener ) {
if( listeners.contains(listener) ) {
logger.log(Level.INFO, "Cannot add MasterswitchListener, it has already been added" );
} else {
listeners.add( listener );
}
} else {
logger.log(Level.WARNING, "Cannot add MasterswitchListener, it is not of the correct instance
type");
}
}
public void removeMasterswitchListener( MasterswitchListener listener ) {
listeners.remove(listener);
}
}