code: public void firePropertyChange(String propertyName, Object oldValue, Object newValue)
      {
          if (propertyChange != null)
              propertyChange.firePropertyChange(propertyName, oldValue, newValue);
      }
docs: The firePropertyChange method was generated to support the propertyChange field.
  @param propertyName The property name.
  @param oldValue The old value.
  @param newValue The new value.