How to use the broker.TOPICS.RESET function in broker

def __init__(self, ctx):
        """ Create a RealTrafficCollector object.
            Subscribe itself to RAW_REQUEST, RAW_RESPONSE and RESET.
        """
        self._ctx = ctx
        self._current_key = None
        self._request_buffer = ""
        self._response_buffer = ""
        self._request_time = None
        self._response_time = None
        self._state = collector.COLLECT_STATE.FINISH_COLLECT
        self._ctx.broker.subscribe(broker.TOPICS.RAW_REQUEST,
                                   self.collect_raw_request)
        self._ctx.broker.subscribe(broker.TOPICS.RAW_RESPONSE,
                                   self.collect_raw_response)
        self._ctx.broker.subscribe(broker.TOPICS.RESET, self._reset)

""" Create a LogCollector object.
            Initialize SwitchCollector with delimiter log.
            Subscribe itself to RAW_LOG and RESET.
        """
        self._ctx = ctx
        self._unique_id_pattern = re.compile(
            r'\[unique_id "([^\]]+)"\]'
        )
        super(LogCollector, self).__init__(
            self._ctx.delimiter.get_delimiter_log(),
            self._ctx.delimiter.get_delimiter_log(), 
            save_entire_line = True)
        self._reset()

        self._ctx.broker.subscribe(broker.TOPICS.RAW_LOG, self)
        self._ctx.broker.subscribe(broker.TOPICS.RESET, self._reset)

def __del__(self):
        self._ctx.broker.unsubscribe(broker.TOPICS.PYWB_OUTPUT, self)
        self._ctx.broker.unsubscribe(broker.TOPICS.RESET, self._reset)

def _start_experiment(self, destination):
        if not os.path.exists(self._conf.pkt_path):
            self._gen_requests()
            if not os.path.exists(self._conf.pkt_path):
                self._ctx.broker.publish(
                    broker.TOPICS.WARNING,
                    " %s is not existed " % (self._conf.pkt_path, ))
                return
        self._ctx.broker.publish(broker.TOPICS.SQL_COMMAND,
                                 sql.SQL_CLEAN_RAW_DATA)
        self._ctx.broker.publish(broker.TOPICS.RESET)

        def collect_pywb_ouput(line):
            self._ctx.broker.publish(broker.TOPICS.PYWB_OUTPUT, line)

        ret = pywb.execute([
            "-F", self._conf.pkt_path, "-v", "4", destination, "-n", "1", "-c",
            "1", "-r", "-s",
            str(self._conf.timeout), "-o", "/dev/null"],
            customized_filters=[collect_pywb_ouput])
        return ret