src/Message/AbstractResponse.php
public function getCountryName($code)
    {
        $name = Intl::getRegionBundle()->getCountryName(strtoupper($code), $this->getRequest()->getLanguageCode() ? : 'en');
        if($name) {
            return $name;
        }
        return $code;
    }
public function getCountryName($code)
    {
        $name = Intl::getRegionBundle()->getCountryName(strtoupper($code), $this->getRequest()->getLanguageCode() ? : 'en');
        if($name) {
            return $name;
        }
        return $code;
    }
Country Name from Code

@param string $code
@return null|string