code: protected AbcTuneBook newAbcTuneBook() {
  		AbcTuneBook ret = new AbcTuneBook();
  		for (int i = 0; i < m_listeners.size(); i++) {
  			Object o = m_listeners.get(i);
  			if (o instanceof TuneBookListenerInterface)
  				ret.addListener((TuneBookListenerInterface) o);
  		}
  		return ret;
  	}
docs: Instanciate a new AbcTuneBook and transfere TuneBookListeners
  to the newly created object