def mixin_user_query(cls):
 name = ('Appender' + cls.__name__)
 return type(name, (AppenderMixin, cls), {'query_class': cls})

def mixin_user_query ( cls ) : name = ( 'Appender' + cls . __name__ ) return type ( name , ( AppenderMixin , cls ) , { 'query_class' : cls } )
return a new class with appenderquery functionality layered over .