public function getCacheClearEventsCacheKey() {
        $design = Mage::getDesign();
        return Mage::helper('turpentine/data')
            ->getCacheKeyHash(array(
                'FILE_LAYOUT_ESI_CACHE_EVENTS',
                $design->getArea(),
                $design->getPackageName(),
                $design->getTheme('layout'),
                Mage::app()->getStore()->getId(),
            ));
    }