#NEWLINE# def test_list_extend( self ) : #NEWLINE# #INDENT# obj = HasListProp ( ) #NEWLINE# self . assertTrue ( isinstance ( obj . foo , PropertyValueList ) ) #NEWLINE# self . _check_mutation ( obj , 'foo' , ( lambda x : x . extend ( [ 'x' , 'y' ] ) ) , [ ] , [ 'x' , 'y' ] )