private function writeCountry()
    {
        $record = 0x008C; // Record identifier
        $length = 4; // Number of bytes to follow

        $header = pack('vv', $record, $length);
        // using the same country code always for simplicity
        $data = pack('vv', $this->countryCode, $this->countryCode);

        return $this->writeData($header . $data);
    }