| // Copyright (c) 2019, 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 A1 { | |
| Object? field; | |
| void method1() {} | |
| } | |
| extension A2 on A1 { | |
| void method2() => this.method1(); | |
| Object? method3() => this.field; | |
| void method4(Object o) { | |
| this.field = o; | |
| } | |
| } | |
| main() { | |
| } |