langchain/tools/youtube/search.py/YouTubeSearchTool/_search
class YouTubeSearchTool:    def _search(self, person: str, num_results: int) -> str:
        from youtube_search import YoutubeSearch

        results = YoutubeSearch(person, num_results).to_json()
        data = json.loads(results)
        url_suffix_list = [video["url_suffix"] for video in data["videos"]]
        return str(url_suffix_list)