throw new Error("not implemented");
Iterator i = listeners.iterator (); PropertyChangeEvent pce = new PropertyChangeEvent (this, property, o, n); while (i.hasNext ()) { PropertyChangeListener pcl = (PropertyChangeListener) i.next (); pcl.propertyChange (pce); }
  protected void firePropertyChange(String property, Object o, Object n)  {    throw new Error("not implemented");  }