code: def _request(self, req_func, end_point, params=None, files=None, **kwargs):
          
          url = self.URL + end_point
          if params and kwargs:
              params.update(kwargs)
          return req_func(url, params=params, files=files)
docs: Send a HTTP request to a Todoist API end-point.
  
          :param req_func: The request function to use e.g. get or post.
          :type req_func: A request function from the :class:`requests` module.
          :param end_point: The Todoist API end-point.
          :type end_point: str
          :param params: The required request parameters.
          :type params: dict
          :param files: Any files that are being sent as multipart/form-data.
          :type files: dict
          :param kwargs: Any optional parameters.
          :type kwargs: dict
          :return: The HTTP response to the request.
          :rtype: :class:`requests.Response`