/**
  * @see Mage_Sales_Model_Order_Shipment::register
  * Registering all shipment items.
  * @param  Mage_Sales_Model_Order_Shipment $shipment
  * @param  string $incrementId
  * @return self
  */
 protected function _registerShipment(Mage_Sales_Model_Order_Shipment $shipment, $incrementId)
 {
     try {
         // attempting to register all shipment items.
         $shipment->register();
     } catch (Mage_Core_Exception $e) {
         $logData = ['increment_id' => $incrementId];
         $logMessage = 'An error occurred registering shipment items for order id "{increment_id}". See exception log for details.';
         $this->_logger->error($logMessage, $this->_context->getMetaData(__CLASS__, $logData));
         $this->_logger->logException($e, $this->_context->getMetaData(__CLASS__, [], $e));
     }
     return $this;
 }