public function generateLabelsForMultiplePackages($package_ids, $outputDocFormat, $outputDocPageFormat, $policy)
 {
     $sessionType = '';
     $packages = array();
     foreach ($package_ids as $id_package_ws) {
         $package = new DpdPolandPackage((int) $id_package_ws);
         if (!$sessionType || $sessionType == $package->getSessionType()) {
             $sessionType = $package->getSessionType();
         } else {
             self::$errors[] = $this->l('Manifests of DOMESTIC shipments cannot be mixed with INTERNATIONAL shipments');
             return false;
         }
         $packages[] = array('packageId' => (int) $id_package_ws);
     }
     $this->prepareSenderAddress();
     $params = array('dpdServicesParamsV1' => array('policy' => $policy, 'session' => array('packages' => $packages, 'sessionType' => $sessionType)), 'outputDocFormatV1' => $outputDocFormat, 'outputDocPageFormatV1' => $outputDocPageFormat, 'pickupAddress' => $this->sender);
     if (!($result = $this->generateSpedLabelsV1($params))) {
         return false;
     }
     if (isset($result['session']['statusInfo']['status']) && $result['session']['statusInfo']['status'] == 'OK') {
         foreach ($packages as $id_package_ws) {
             $package = new DpdPolandPackage($id_package_ws);
             $package->labels_printed = 1;
             $package->update();
         }
         return $result['documentData'];
     } else {
         $packages = $result['session']['statusInfo'];
         $packages = array_values($packages) === $packages ? $packages : array($packages);
         // array must be multidimentional
         foreach ($packages as $package) {
             if (isset($package['description'])) {
                 self::$errors[] = $package['description'];
             } elseif (isset($package['status'])) {
                 self::$errors[] = $package['status'];
             }
         }
         return false;
     }
 }