public static function checkZipCode($zipCode) {
        $zipCode = self::cleanZipCode($zipCode);

        if (!empty($zipCode) && strlen($zipCode) > self::$_inputFldMaxLength['ZipCode']) {
            $errorMessage = 'The value for zip code can be no more than ' . self::$_inputFldMaxLength['ZipCode'] . ' characters, Please try again after making corrections';
            throw new HpsInvalidRequestException(
            HpsExceptionCodes::INVALID_ZIP_CODE, $errorMessage
            );
        }
        return $zipCode;
    }