langchain/chains/llm_checker/base.py/LLMCheckerChain/_call
class LLMCheckerChain:    def _call(
        self,
        inputs: Dict[str, Any],
        run_manager: Optional[CallbackManagerForChainRun] = None,
    ) -> Dict[str, str]:
        _run_manager = run_manager or CallbackManagerForChainRun.get_noop_manager()
        question = inputs[self.input_key]

        output = self.question_to_checked_assertions_chain(
            {"question": question}, callbacks=_run_manager.get_child()
        )
        return {self.output_key: output["revised_statement"]}