code: public void elementChanged(E element) {
  		int idx = getIndexOf(element);
  		if (idx < 0) {
  			return;
  		}
  		super.fireContentsChanged(this, idx, idx);
  	}
docs: Notifies the listeners that the given {@code element} of the combo box model was changed.
  <p>
  The call to this method has no effect if the given {@code element} doesn't exist in the combo box model.
  </p>
  
  @param element the element that was changed.
  @since 2.3.0