public function get($countryCode)
    {
        if (strlen($countryCode) !== 2) {
            throw new \InvalidArgumentException('Please provide a 2 character country code.');
        }

        $countryCode = strtoupper($countryCode);

        if (array_key_exists($countryCode, $this->aliases)) {
            $countryCode = $this->aliases[$countryCode];
        }

        return implode('', array_map([$this, 'toUnicode'], str_split($countryCode)));
    }