Focus first focusable element below a Focus widget - flutter

Question

I am trying to focus the first focusable element below a Focus widget. Consider the following artifical example. It contains a BarWidget with some TextField.
The FooWidget wraps it into a Focus widget with the given focusNode. After one second, I'd like to focus the first element of BarWidget. Please not that I don't want to pass a FocusNode down into BarWidget.
import 'package:flutter/material.dart';
void main() {
runApp(Foo());
}
class Foo extends StatefulWidget {
#override
State createState() => FooState();
}
class FooState extends State<Foo> {
final focusNode = FocusNode();
void initState() {
super.initState();
Future.delayed(
const Duration(seconds: 1),
focusNode.requestFocus,
);
}
#override
Widget build(BuildContext context) => MaterialApp(
home: Scaffold(
body: Focus(
focusNode: focusNode,
child: BarWidget(),
),
),
);
}
class BarWidget extends StatelessWidget {
#override
Widget build(BuildContext context) => Column(
children: [
Text("Foo"),
TextField(),
Text("Bar"),
],
);
}

Answer 1

It is in theory possible by using FocusTraversalPolicy.sortDescendants. However, that method is declared as #protected. See: https://github.com/flutter/flutter/issues/70534
Full example:
import 'package:flutter/material.dart';
void main() {
runApp(Foo());
}
class Foo extends StatefulWidget {
#override
State createState() => FooState();
}
class FooState extends State<Foo> {
final focusNode = FocusNode(canRequestFocus: false);
void initState() {
super.initState();
void f() {
final policy = FocusTraversalGroup.of(focusNode.context);
// ignore: invalid_use_of_protected_member
final node = policy.sortDescendants(focusNode.traversalDescendants, null).first;
node.requestFocus();
}
Future.delayed(
const Duration(seconds: 1),
f,
);
}
#override
Widget build(BuildContext context) => MaterialApp(
home: Scaffold(
body: Focus(
focusNode: focusNode,
child: BarWidget(),
),
),
);
}
class BarWidget extends StatelessWidget {
#override
Widget build(BuildContext context) => Column(
children: [
Text("Foo"),
TextField(),
Text("Bar"),
],
);
}