langchain/utilities/wikipedia.py/WikipediaAPIWrapper/_fetch_page
class WikipediaAPIWrapper:    def _fetch_page(self, page: str) -> Optional[str]:
        try:
            return self.wiki_client.page(title=page, auto_suggest=False)
        except (
            self.wiki_client.exceptions.PageError,
            self.wiki_client.exceptions.DisambiguationError,
        ):
            return None