public function getWsdlUrl(CertificationBag $certificationBag, $url = null)
    {
        if ($url) {
            return $url;
        }

        if ($certificationBag->getEnvironment() == CertificationBag::PRODUCTION) {
            return static::PRODUCTION_WSDL;
        }

        return static::INTEGRATION_WSDL;
    }