langchain/chains/llm.py/LLMChain/_parse_result
class LLMChain:    def _parse_result(
        self, result: List[Dict[str, str]]
    ) -> Sequence[Union[str, List[str], Dict[str, str]]]:
        if self.prompt.output_parser is not None:
            return [
                self.prompt.output_parser.parse(res[self.output_key]) for res in result
            ]
        else:
            return result