How to use the intspan.intspan function in intspan

log.info('missing: checking for missed segments')

    with db_session() as db:
        # recheck for anything to delete
        expired = db.query(Miss).filter(Miss.attempts >= config.scan.get('miss_retry_limit')).filter(
            Miss.group_name == group_name).delete()
        db.commit()
        if expired:
            log.info('missing: deleted {} expired misses'.format(expired))

        # get missing articles for this group
        missing_messages = [r for r, in db.query(Miss.message).filter(Miss.group_name == group_name).all()]

        if missing_messages:
            # mash it into ranges
            missing_ranges = intspan(missing_messages).ranges()

            server = Server()
            server.connect()

            status, parts, messages, missed = server.scan(group_name, message_ranges=missing_ranges)

            # if we got some missing parts, save them
            if parts:
                pynab.parts.save_all(parts)

            # even if they got blacklisted, delete the ones we got from the misses
            if messages:
                db.query(Miss).filter(Miss.message.in_(messages)).filter(Miss.group_name == group_name).delete(False)

            db.commit()