public function setTtl(int $ttl = 86400) : CNabuDataObject
    {
        if ($ttl === null) {
            throw new ENabuCoreException(
                    ENabuCoreException::ERROR_NULL_VALUE_NOT_ALLOWED_IN,
                    array("\$ttl")
            );
        }
        $this->setValue('nb_domain_zone_ttl', $ttl);
        
        return $this;
    }