Describe how to implement a twin generics inheritance with dart

dart_generic_inheritance.dart

/// 
/// @see https://dartpad.dev/660a4ec4fcb91ff648a632705ea4697a
/// 
import 'package:flutter_test/flutter_test.dart';

/// base controller, just to explain the main inheritance
class BaseController {}

class BaseScreen<T extends BaseController> {
  late final T controller;
  BaseScreen(this.controller);

  String get name => runtimeType.toString();
}

/// Intermediate abstract [AbstractIntermediateController]
/// which extends a common base controller
abstract class AbstractIntermediateController extends BaseController {}

abstract class AbstractIntermediateScreen<T extends AbstractIntermediateController> extends BaseScreen<T> {
  AbstractIntermediateScreen(T controller) : super(controller);
}

/// Specialized late controller
class FirstController extends AbstractIntermediateController {
  String sayFirst() => '1';
}

class FirstScreen<T extends FirstController> extends AbstractIntermediateScreen<T> {
  FirstScreen(T controller) : super(controller);
}

/// Specialized late controller
class SecondController extends AbstractIntermediateController {
  String saySecond() => '2';
}

class SecondScreen<T extends SecondController> extends AbstractIntermediateScreen<T> {
  SecondScreen(T controller) : super(controller);
}

void main() {
  test('test inheritance', () {
    var first = FirstScreen(FirstController());
    first.controller.sayFirst();
    var second = SecondScreen(SecondController());
    second.controller.saySecond();

    expect('FirstScreen<FirstController> + SecondScreen<SecondController>', '${first.name} + ${second.name}');
  });
}