def _remove_expired_items_from_cache(self):
        """Remove expired items from temporary URL cache

        This function removes entries that will expire before the expected
        usage time.
        """
        max_valid_time = (
            int(time.time()) +
            CONF.glance.swift_temp_url_expected_download_start_delay)
        keys_to_remove = [
            k for k, v in six.iteritems(self._cache)
            if (v.url_expires_at < max_valid_time)]
        for k in keys_to_remove:
            del self._cache[k]
dataset/ETHPy150Open openstack/ironic/ironic/common/glance_service/v2/image_service.py/GlanceImageService._remove_expired_items_from_cache/original