langchain/llms/human.py/HumanInputLLM/_call
class HumanInputLLM:    def _call(
        self,
        prompt: str,
        stop: Optional[List[str]] = None,
        run_manager: Optional[CallbackManagerForLLMRun] = None,
    ) -> str:
        """
        Displays the prompt to the user and returns their input as a response.

        Args:
            prompt (str): The prompt to be displayed to the user.
            stop (Optional[List[str]]): A list of stop strings.
            run_manager (Optional[CallbackManagerForLLMRun]): Currently not used.

        Returns:
            str: The user's input as a response.
        """
        self.prompt_func(prompt, **self.prompt_kwargs)
        user_input = self.input_func(
            separator=self.separator, stop=stop, **self.input_kwargs
        )

        if stop is not None:
            # I believe this is required since the stop tokens
            # are not enforced by the human themselves
            user_input = enforce_stop_tokens(user_input, stop)
        return user_input