How to use the mindmeld.components.dialogue.DialogueResponder.to_json function in mindmeld

def freeze_params(params):
    """
    If params is a dictionary or Params we convert it into FrozenParams.
    Otherwise we raise a TypeError.

    Args:
        params (dict, Params): The input params to convert

    Returns:
        FrozenParams: The converted params object
    """
    params = params or FrozenParams()
    if isinstance(params, dict):
        params = FrozenParams(**params)
    elif params.__class__ == Params:
        params = FrozenParams(**DialogueResponder.to_json(params))
    elif not isinstance(params, FrozenParams):
        raise TypeError(
            "Invalid type for params argument. "
            "Should be dict or {}".format(FrozenParams.__name__)
        )
    return params

def to_json(instance):
        """Convert the responder into a JSON representation.
        Args:
             instance (DialogueResponder): The responder object.

        Returns:
            (dict): The JSON representation.
        """
        serialized_obj = {}
        for attribute, value in vars(instance).items():
            if isinstance(value, (Params, Request, FrozenParams)):
                serialized_obj[attribute] = DialogueResponder.to_json(value)
            elif isinstance(value, immutables.Map):
                serialized_obj[attribute] = dict(value)
            else:
                serialized_obj[attribute] = value
        return serialized_obj

def _post_dm(self, request, dm_response):
        # Append this item to the history, but don't recursively store history
        prev_request = DialogueResponder.to_json(dm_response)
        prev_request.pop("history")

        # limit length of history
        new_history = (prev_request,) + request.history
        dm_response.history = new_history[: self.MAX_HISTORY_LEN]

        # validate outgoing params
        dm_response.params.validate_param("allowed_intents")
        dm_response.params.validate_param("target_dialogue_state")
        return dm_response

"""The main endpoint for the MindMeld API"""
            request_json = request.get_json()
            if request_json is None:
                msg = "Invalid Content-Type: Only 'application/json' is supported."
                raise BadMindMeldRequestError(msg, status_code=415)

            safe_request = {}
            for key in ["text", "params", "context", "frame", "history", "verbose"]:
                if key in request_json:
                    safe_request[key] = request_json[key]
            response = self._app_manager.parse(**safe_request)
            # add request id to response
            # use the passed in id if any
            request_id = request_json.get("request_id", str(uuid.uuid4()))
            response.request_id = request_id
            return jsonify(DialogueResponder.to_json(response))