pkg/front_end/testcases/general/override_check_basic.dart.textual_outline.expect

class A {}

class B extends A {}

class C {
  void f1(A x) {}
  void f2([A? x]) {}
  void f3({A? x}) {}
  A? f4() {}
}

class D extends C {
  void f1(Object x) {}
  void f2([Object? x]) {}
  void f3({Object? x}) {}
  B? f4() {}
}

class E extends C {
  void f1(B x) {}
  void f2([B? x]) {}
  void f3({B? x}) {}
  Object? f4() {}
}

main() {}