protected function prepareKeyword($keyword)
    {
        if ($this->config->isCaseInsensitive()) {
            $keyword = Str::lower($keyword);
        }

        if ($this->config->isWildcard()) {
            $keyword = Helper::wildcardLikeString($keyword);
        }

        if ($this->config->isSmartSearch()) {
            $keyword = "%$keyword%";
        }

        return $keyword;
    }