Args:
            serialized (Dict[str, Any]): The serialized LLM.
            messages (List[List[BaseMessage]]): The list of messages.
            run_id (UUID, optional): The ID of the run. Defaults to None.
        Returns:
            List[CallbackManagerForLLMRun]: A callback manager for each
                list of messages as an LLM run.
        """
        managers = []
        for message_list in messages:
            run_id_ = uuid.uuid4()
            _handle_event(
                self.handlers,
                "on_chat_model_start",
                "ignore_chat_model",
                serialized,
                [message_list],
                run_id=run_id_,
                parent_run_id=self.parent_run_id,
                tags=self.tags,
                metadata=self.metadata,
                **kwargs,
            )
            managers.append(
                CallbackManagerForLLMRun(
                    run_id=run_id_,
                    handlers=self.handlers,
                    inheritable_handlers=self.inheritable_handlers,
                    parent_run_id=self.parent_run_id,
                    tags=self.tags,
                    inheritable_tags=self.inheritable_tags,
                    metadata=self.metadata,
                    inheritable_metadata=self.inheritable_metadata,
                )
            )
        return managers
[docs]    def on_chain_start(
        self,
        serialized: Dict[str, Any],
        inputs: Union[Dict[str, Any], Any],
        run_id: Optional[UUID] = None,
        **kwargs: Any,
    ) -> CallbackManagerForChainRun:
        """Run when chain starts running.
        Args:
            serialized (Dict[str, Any]): The serialized chain.
            inputs (Union[Dict[str, Any], Any]): The inputs to the chain.