public function isZoneHidden()
    {
        if (!method_exists($this, 'getZone')) {
            throw new ENabuCoreException(ENabuCoreException::ERROR_FEATURE_NOT_IMPLEMENTED);
        }

        $zone = $this->getZone();

        return $zone !== CNabuSite::ZONE_PUBLIC && $zone !== CNabuSite::ZONE_PRIVATE && $zone !== CNabuSite::ZONE_HIDDEN;
    }