def _create_chat_completion(
        self,
        prompt: Optional[str] = None,
        messages: Optional[Sequence[Dict]] = None,
        **kwargs,
    ) -> str:
        """
        Chat Completion Model

        Returns:
            str: Completion model response.
        """
        # text
        raise NotImplementedError()

        Chat Completion Model

        Returns:
            str: Completion model response.
        
src/feedback/trulens/feedback/llm_provider.py