private function getRegionAbbreviation($shipping)
    {
        if (strlen($shipping->getRegionCode()) == 2) {
            return $shipping->getRegionCode();
        }

        $regionAbbreviation = new \PagSeguro\Enum\Address();

        return (is_string($regionAbbreviation->getType($shipping->getRegion()))) ?
            $regionAbbreviation->getType($shipping->getRegion()) :
            $shipping->getRegion();
    }