class A {
  int? get bar => null;
  void set foo(int? value) {}
}

class B {
  double? get bar => null;
  void set foo(double? value) {}
}

class C {
  Null get bar => null;
  void set foo(num? value) {}
}

class D implements C, A, B {
  noSuchMethod(_) => null;
}

main() {}