(self, filter)
return query
Add the passed-in filter to the query.  All filtering goes through
        this class.
Add the passed-in filter to the query.  All filtering goes through
        this class.
Add the passed - in filter to the query . All filtering goes through this class .
def filter(self, filter):
        """
        Add the passed-in filter to the query.  All filtering goes through
        this class.
        """
        query = deepcopy(self)
        query._filters.append(filter)
        return query
def filter ( self , filter ) : query = deepcopy ( self ) query . _filters . append ( filter ) return query