def __init__(self, filtr=None, query=None):
        """
        Construct a virtual sctid set
        :param filtr: One of a textual SQL filter, a generator for SCTID's or None (wild card)
        :param query: A complete query -- result of and, or or minus
        """
        Set.__init__(self, Sctids)
        _Instance.__init__(self, Sctids)
        RF2_Substrate_Common.__init__(self)
        self._val = self
        self._type = sctId

        if query is not None:
            self._query = query
        else:
            if filtr is not None and not isinstance(filtr, str):
                sctid_list = filtr if isinstance(filtr, Container) else [filtr]
                if sctid_list:
                    filtr = 'id IN (' + ','.join(str(e) for e in sctid_list) + ')'
                else:
                    filtr = ' False '
            self._query = self._db.buildQuery(**self._build_parms(filtr))
 def __init__(self):
     Set.__init__(self, Sctids)
     self._type = sctId