langchain/chains/api/openapi/response_chain.py/APIResponderOutputParser/parse
class APIResponderOutputParser:    def parse(self, llm_output: str) -> str:
        """Parse the response and error tags."""
        json_match = re.search(r"```json(.*?)```", llm_output, re.DOTALL)
        if json_match:
            return self._load_json_block(json_match.group(1).strip())
        else:
            raise ValueError(f"No response found in output: {llm_output}.")