class Class {
  late ;
  final int? field;
  Class.constructor1();
  Class.constructor2(this.field);
  Class.constructor3(int value) : this.field = value + 1;
  Class.constructor4([this.field = 42]);
}
class Subclass extends Class {
  Subclass.constructor1() : super.constructor1();
  Subclass.constructor2(int value) : super.constructor2(value);
  Subclass.constructor3(int value) : super.constructor3(value);
  Subclass.constructor4([int value = 87]) : super.constructor4(value);
}
test1() { }
test2() { }
main() { }
expect(expected, actual) { }
throws(f(), String message) { }