Resolved: How to get a subset of items from a list in an AsyncNotifierProvider in Riverpod 2.0?

@immutable
class Todo {
  const Todo({
    required this.id,
    required this.description,
    required this.completed,
  });

  factory Todo.fromJson(Map<String, dynamic> map) {
    return Todo(
      id: map['id'] as String,
      description: map['description'] as String,
      completed: map['completed'] as bool,
    );
  }

  // All properties should be `final` on our class.
  final String id;
  final String description;
  final bool completed;
}

class AsyncTodosNotifier extends AsyncNotifier<List<Todo>> {
  Future<List<Todo>> _fetchTodo() async {
    final json = await http.get('api/todos');
    final todos = jsonDecode(json) as List<Map<String, dynamic>>;
    return todos.map((todo) => Todo.fromJson(todo)).toList();
  }

  @override
  Future<List<Todo>> build() async {
    return _fetchTodo();
  }

// ... several CRUD methods
}

final asyncTodosProvider =
    AsyncNotifierProvider<AsyncTodosNotifier, List<Todo>>(() {
  return AsyncTodosNotifier();
});

class TodoListView extends ConsumerWidget {
  const TodoListView({Key? key}) : super(key: key);

  @override
  Widget build(BuildContext context, WidgetRef ref) {
    final asyncTodos = ref.watch(asyncTodosProvider);

    return asyncTodos.when(
      data: (todos) => ListView(
        children: todos.map(
          (todo) {
            if (todo.completed) {
              return ListTile(
                title: Text(todo.description),
              );
            } else {
              return Container();
            }
          },
        ).toList(),
      ),
      loading: () => const Center(
        child: CircularProgressIndicator(),
      ),
      error: (err, stack) => Text('Error: $err'),
    );
  }
}

// Original (full) list
final asyncTodosProvider =
    AsyncNotifierProvider<AsyncTodosNotifier, List<Todo>>(() {
  return AsyncTodosNotifier();
});

// Filtered List
final completedTodosProvider = FutureProvider<List<Todo>>(
  (ref) async {
    final todos = await ref.watch(asyncTodosProvider.future);
    return todos.where((e) => e.isCompleted).toList();
  },
);