// 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. // @dart=2.9 library test; typedef void F(T t); class B { T f(int x) {} } abstract class I { T f(Object x); } abstract class C extends B> implements I> {} void main() {}