langchain/tools/metaphor_search/tool.py/MetaphorSearchResults/_arun
class MetaphorSearchResults:    async def _arun(
        self,
        query: str,
        num_results: int,
        run_manager: Optional[AsyncCallbackManagerForToolRun] = None,
    ) -> Union[List[Dict], str]:
        """Use the tool asynchronously."""
        try:
            return await self.api_wrapper.results_async(query, num_results)
        except Exception as e:
            return repr(e)