public function getLibSrc($ver = null)
    {
        if ($ver == null) {
            $ver = $this->getVersion();
        }

        if (!$ver) {
            $ver = $this->defVersion;
        }

        $return = false;

        /** @var $service InterfaceDelivery */
        foreach ($this->getLibDelivers() as $name => $service) {
            $return = $service->getLibSrc($ver);
            if ($return) {
                break;
            }
        }

        if (!$return) {
            throw new \Exception('Can`t resolve to library.');
        }

        return $return;
    }