field_duplication.dart

class User {
  final String name;
  User({required this.name});
}

class SuperchargedUser extends User {
  final String ability;
  // no duplication of the "final String name;" here

  SuperchargedUser({super.key, super.name, required this.ability});
}

class UserTile extends StatelessWidget {
  final String name;

  const UserTile({Key? key, required this.name}) : super(key: key);

  @override
  Widget build(BuildContext context) {
    return Text(name);
  }
}

class SuperchargedUserTile extends StatelessWidget {
  final String ability;
  // You have to declare this again, in order to be able to access this 
  // inside build.
  final String name;

  const SuperchargedUserTile({super.key, required this.ability, required this.name});

  @override
  Widget build(BuildContext context) {
    return Row(
      children: [
        UserTile(name: name),
        Text(ability),
      ],
    );
  }
}