private function isInvalidOctalInteger($tokens, $stackPtr)
    {
        $token = $tokens[$stackPtr];

        if ($token['code'] === \T_LNUMBER && preg_match('`^0[0-7]*[8-9]+[0-9]*$`D', $token['content']) === 1) {
            return true;
        }

        return false;
    }