protected function _loadEsiCacheClearEvents() {
        Varien_Profiler::start('turpentine::helper::esi::_loadEsiCacheClearEvents');
        $layoutXml = $this->getLayoutXml();
        $events = $layoutXml->xpath(
            '//action[@method=\'setEsiOptions\']/params/flush_events/*' );
        if ($events) {
            $events = array_unique(array_map(
                create_function('$e',
                    'return (string)$e->getName();'),
                $events ));
        } else {
            $events = array();
        }
        Varien_Profiler::stop('turpentine::helper::esi::_loadEsiCacheClearEvents');
        return $events;
    }