def is_stale(self, file_name):
        """
        Determines whether the cache-tier server should be contacted to
        refresh information about the availability of this file based on
        the set cache usage and timings.

        :param file_name: The base file name (e.g. episode.mp3)
        :return: True of False whether the file info needs refreshed.
        """
        self.__validate_file_name(file_name)
        file_name = os.path.basename(file_name.strip())

        if not self.enabled:
            return True

        item = CacheTierClient.__remote_status_cache.get(
            file_name.lower(), (None, False))

        last_request, available = item
        if last_request is None:
            return True

        dt = timedelta(seconds=self.local_cache_time)
        valid_range = last_request + dt
        return datetime.now() < valid_range
dataset/ETHPy150Open mikeckennedy/cache-tier/src/client/cache-tier-client-pkg/cache_tier/cache_client.py/CacheTierClient.is_stale/swapped operands of `<`