public function setReplaceFormKeyFlag($eventObject) {
        $esiHelper = Mage::helper('turpentine/esi');
        $varnishHelper = Mage::helper('turpentine/varnish');
        $request = Mage::app()->getRequest();
        if ($esiHelper->shouldResponseUseEsi() &&
                $varnishHelper->csrfFixupNeeded() &&
                ! $request->isPost()) {
            Mage::register('replace_form_key', true);
        }
    }