'Removes the old items in the list'

def trim(self):

    key = self.get_key()
    removed = self.redis.ltrim(key, 0, (self.max_items - 1))
    msg_format = 'cleaning    up    the    list    %s    to    a    max    of    %s    items'
    logger.info(msg_format, self.get_key(), self.max_items)
    return removed
