'Check cell against the last_seen timestamp that indicates the time
that the most recent capability or capacity update was received from
the given cell.'

def _weigh_object(self, cell, weight_properties):

    last_seen = cell.last_seen
    secs = CONF.cells.mute_child_interval
    if timeutils.is_older_than(last_seen, secs):
        LOG.warning('%(cell)s    has    not    been    seen    since    %(last_seen)s    and    is    being    treated    as    mute.', {'cell': cell, 'last_seen': last_seen})
        return self.MUTE_WEIGH_VALUE
    else:
        return 0
