public void addPreferenceChangeListener(PreferenceChangeListener listener) {
public void addPreferenceChangeListener(PreferenceChangeListener listener) { synchronized (lock) { if (isRemoved()) throw new IllegalStateException("node has been removed"); if (listener == null) throw new NullPointerException("listener is null"); if (preferenceListeners == null) preferenceListeners = new ArrayList(); preferenceListeners.add(listener); }
	public void addPreferenceChangeListener(PreferenceChangeListener listener) {		// XXX	}