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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def _request(self, req_func, end_point, params=None, files=None, **kwargs):
 """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` """

        url = self.URL + end_point
        if params and kwargs:
            params.update(kwargs)
        return req_func(url, params=params, files=files)