/** @inheritdoc */
public function getBusCodeForShippingMethod(\Magento\Sales\Api\Data\OrderInterface $order)
{
$result = null;
$mage = $order->getShippingMethod();
if ($mage == self::M_SHIP_FLAT_RATE) {
$result = self::B_SHIP_FLAT_RATE;
}
return $result;
}
