// 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.
// @dart=2.9
// This is a regression test for http://dartbug.com/39421.

class A {}

class A {}

class B {
  foo(List<Null> a) {}
}

class C extends B {
  foo(List<A> a) {}
}

main() {}