|  | // Copyright (c) 2017, the Dart project authors.  Please see the AUTHORS file | 
|  | // for details. All rights reserved. Use of this source code is governed by a | 
|  | // BSD-style license that can be found in the LICENSE file. | 
|  |  | 
|  | class A {} | 
|  |  | 
|  | class B extends A {} | 
|  |  | 
|  | class Base { | 
|  | void g(B b) {} | 
|  | } | 
|  |  | 
|  | class C extends Base { | 
|  | void f(A a) { | 
|  | g(a); | 
|  | //^ | 
|  | // [analyzer] COMPILE_TIME_ERROR.ARGUMENT_TYPE_NOT_ASSIGNABLE | 
|  | // [cfe] The argument type 'A' can't be assigned to the parameter type 'B'. | 
|  | } | 
|  | } | 
|  |  | 
|  | main() { | 
|  | C c = new C(); | 
|  | A a = new B(); | 
|  | c.f(a); | 
|  | } |