def _set_binops_check_loose(self, obj):
 return (isinstance(obj, (_set_binop_bases + (self.__class__,))) or (util.duck_type_collection(obj) == set))

def _set_binops_check_loose ( self , obj ) : return ( isinstance ( obj , ( _set_binop_bases + ( self . __class__ , ) ) ) or ( util . duck_type_collection ( obj ) == set ) )
allow anything set-like to participate in set binops .