pkg/front_end/testcases/general/demote_closure_types.dart

// Copyright (c) 2020, 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
method<T>(T a, T b) {
  if (a is String) {
    var f = () => a;
    String s = f();
  }
}

main() {}