private void removePropertyChangeListeners() {
CarRoads.instance().removePropertyChangeListener(this);
engineModels.removePropertyChangeListener(this);
engineTypes.removePropertyChangeListener(this);
engineLengths.removePropertyChangeListener(this);
CarOwners.instance().removePropertyChangeListener(this);
locationManager.removePropertyChangeListener(this);
manager.removePropertyChangeListener(this);
}
@Override
public void dispose() {
locationManager.removePropertyChangeListener(this);
super.dispose();
}