langchain/callbacks/arize_callback.py/ArizeCallbackHandler/on_llm_start
class ArizeCallbackHandler:    def on_llm_start(
        self, serialized: Dict[str, Any], prompts: List[str], **kwargs: Any
    ) -> None:
        """Record the prompts when an LLM starts."""

        for prompt in prompts:
            self.prompt_records.append(prompt.replace("\n", " "))