code: def start_prompt(self, message, text_input=False, cli_color=''):
      
      with self._cond:
        if self._prompt:
          raise MultiplePromptsError
        prompt_id = uuid.uuid4().hex
        _LOG.debug('Displaying prompt (%s): "%s"%s', prompt_id, message,
                   ', Expects text input.' if text_input else '')
  
        self._response = None
        self._prompt = Prompt(
            id=prompt_id, message=message, text_input=text_input)
        if sys.stdin.isatty():
          self._console_prompt = ConsolePrompt(
              message, functools.partial(self.respond, prompt_id), cli_color)
          self._console_prompt.start()
  
        self.notify_update()
        return prompt_id
docs: Display a prompt.
  
      Args:
        message: A string to be presented to the user.
        text_input: A boolean indicating whether the user must respond with text.
        cli_color: An ANSI color code, or the empty string.
  
      Raises:
        MultiplePromptsError: There was already an existing prompt.
  
      Returns:
        A string uniquely identifying the prompt.