protected function log_error($errors) {
        if (empty($errors)) {
            return;
        }

        foreach ($errors as $code => $langstring) {
            if (!isset($this->errors[$this->linenb])) {
                $this->errors[$this->linenb] = array();
            }
            $this->errors[$this->linenb][$code] = $langstring;
        }
    }