app/code/community/Nexcessnet/Turpentine/controllers/EsiController.php
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());
    }
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());
    }
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 ( ) ) ; }
Spit out the form key for this session

@return null
Spit out the form key for this session