how to notify listeners if Observable class is deprecated

how to Notify listeners if the Observable class is deprecated, there is a listener. I need to notify all listeners that there has been a language change. The listener is not working, because deprecated class Observable if version high 9.

interface with a single update method

    public interface ListenObservable {
         void update(ListenObservable o, Object arg);
    }

implementation of a class, almost a copy of Observable

    public class ListenObservableImpl  {
    
        private boolean changed = false;
    
        private ArrayList<ListenObservableImpl> obs;

/**
 * Construct an Observable with zero Observers.
 */

public ListenObservableImpl() {
    obs = new ArrayList<>();
}
    
    
        public void notifyObservers() {
            notifyObservers(null);
        }
    
        public void notifyObservers(Object arg) {
    
            Object[] arrLocal;
    
            synchronized (this) {
                if (!changed)
                    return;
                arrLocal = obs.toArray();
                clearChanged();
            }
    
    
            for (int i = arrLocal.length - 1; i >= 0; i--) {
                ((ListenObservableImpl) arrLocal[i]).update(this, arg));
            }
        }
    
    
        protected synchronized void clearChanged() {
            changed = false;
        }
    
        protected synchronized void setChanged() {
            changed = true;
        }
    
    
        public synchronized void addObserver(ListenObservableImpl o) {
            if (o == null)
                throw new NullPointerException();
            if (!obs.contains(o)) {
                obs.addElement(o);
            }
        }
    
    
        public synchronized boolean hasChanged() {
            return changed;
        }
    //
    //    private void setValid(Boolean valid) {
    //        this.valid = valid;
    //    }
         private void update(ListenObservable o, Object arg) {

          }
    }

    ...
    @FXML
    private ComboBox changeLocaleBox; 
    ...



    // listens to language change
     changeLocaleBox.setOnAction(new EventHandler<ActionEvent>() {
            @Override
            public void handle(ActionEvent event) {
                Language selectedLang = (Language) changeLocaleBox.getSelectionModel().getSelectedItem();
                ManagerLocale.setCurrentLang(selectedLang);

                // I need to notify all listeners that there has been a language change.
                setChanged();  //Deprecated class Observable
                notifyObservers(selectedLang); //Deprecated class Observable
            }
        });