public function getFormKeyAction() {
        $resp = $this->getResponse();
        $resp->setBody(
            Mage::getSingleton('core/session')->real_getFormKey() );
        $resp->setHeader('X-Turpentine-Cache', '1');
        $resp->setHeader('X-Turpentine-Flush-Events',
            implode(',', Mage::helper('turpentine/esi')
                ->getDefaultCacheClearEvents()));
        $resp->setHeader('X-Turpentine-Block', 'form_key');
        Mage::register('turpentine_nocache_flag', false, true);

        Mage::helper('turpentine/debug')->logDebug('Generated form_key: %s',
            $resp->getBody());
    }