public function getCountry($countryCode)
    {
        // accept lowercase country codes
        $countryCode = strtoupper($countryCode);

        $result = current(array_filter($this->countries, function ($country) use ($countryCode) {
            /** @var VATCountry $country */
            return ($country->getCode() == $countryCode || $country->getCountryCode() == $countryCode);
        }));

        return $result != false ? $result : null;
    }