/**
* Get the data rows and return a renderer ready to be used
*
* Overrides the default method to customize the levels to be
* returned by the renderer.
*
* @param string $action The action template string
* @return HTML_Menu_TipRenderer|null The renderer or
* null on errors
*/
protected function &_getRenderer($action)
{
if (!is_null($renderer = parent::_getRenderer($action))) {
$renderer->setLevels($this->levels);
}
return $renderer;
}