protected function _getLengthForCountry($sIBAN)
    {
        $aIBANRegistry = $this->getCodeLengths();

        $sCountryCode = getStr()->substr($sIBAN, 0, 2);

        $iCorrectLength = (isset($aIBANRegistry[$sCountryCode])) ? $aIBANRegistry[$sCountryCode] : null;

        return $iCorrectLength;
    }