protected function _initAllowedPages()
    {
        if ($this->_allowedPages === null) {
            $this->_allowedPages = array();
            
            foreach (Mage::getConfig()->getNode(self::XML_PATH_ALLOWED_PAGES)->children() as $page => $info) {
                $module = ($info->getAttribute('module') ? $info->getAttribute('module') : 'ecomdev_varnish');
                $this->_allowedPages[$page] = Mage::helper($module)->__((string)$info->label);
            }
        }
        
        return $this;
    }