private ChemObjectNotifier notifier = new ChemObjectNotifier();

    /** {@inheritDoc} */
	public void addListener(IChemObjectListener col) {
		notifier.addListener(col);
	}

    /** {@inheritDoc} */
	public int getListenerCount() {
		return notifier.getListenerCount();
	}

    /** {@inheritDoc} */
	public void removeListener(IChemObjectListener col) {
        notifier.removeListener(col);
	}

    /** {@inheritDoc} */
	public void notifyChanged() {
        notifier.notifyChanged();
	}

    /** {@inheritDoc} */
	public void notifyChanged(IChemObjectChangeEvent evt) {
        notifier.notifyChanged(evt);
	}