pkg/front_end/testcases/runtime_checks/covariant_keyword_field.dart

// 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
/*@testedFeatures=checks*/
library test;

class C {
  num x;
}

class D implements C {
  covariant int x;
}

class E implements D {
  int x;
}

main() {}