':return: True if the value is in our list.'

def __contains__(self, value):

    assert (self._state == OPEN)
    t = (self._get_eq_attrs_values(value),)
    query = ('SELECT    count(*)    FROM    %s    WHERE    eq_attrs=?    LIMIT    1' % self.table_name)
    r = self.db.select_one(query, t)
    return bool(r[0])
