run_managers = await callback_manager.on_chat_model_start(
            dumpd(self),
            messages,
            invocation_params=params,
            options=options,
            name=run_name,
        )
        results = await asyncio.gather(
            *[
                self._agenerate_with_cache(
                    m,
                    stop=stop,
                    run_manager=run_managers[i] if run_managers else None,
                    **kwargs,
                )
                for i, m in enumerate(messages)
            ],
            return_exceptions=True,
        )
        exceptions = []
        for i, res in enumerate(results):
            if isinstance(res, BaseException):
                if run_managers:
                    await run_managers[i].on_llm_error(res)
                exceptions.append(res)
        if exceptions:
            if run_managers:
                await asyncio.gather(
                    *[
                        run_manager.on_llm_end(
                            LLMResult(
                                generations=[res.generations], llm_output=res.llm_output
                            )
                        )
                        for run_manager, res in zip(run_managers, results)
                        if not isinstance(res, Exception)
                    ]
                )
            raise exceptions[0]
        flattened_outputs = [
            LLMResult(generations=[res.generations], llm_output=res.llm_output)
            for res in results
        ]
        llm_output = self._combine_llm_outputs([res.llm_output for res in results])
        generations = [res.generations for res in results]
        output = LLMResult(generations=generations, llm_output=llm_output)
        await asyncio.gather(
            *[
                run_manager.on_llm_end(flattened_output)
                for run_manager, flattened_output in zip(