Flutter - Container with hole

main.dart

import 'package:flutter/material.dart';

void main() => runApp(MyApp());

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      debugShowCheckedModeBanner: false,
      home: Scaffold(
        backgroundColor: Colors.blue,
        appBar: AppBar(
          title: Text('Container with hole'),
        ),
        body: Center(
          child: Container(
            child: Stack(
              children: [
                Image.network(
                  'https://picsum.photos/250?image=9',
                ),
                Container(
                  width: 250,
                  height: 250,
                  color: Colors.transparent,
                  child: CustomPaint(
                    painter: Hole(),
                  ),
                )
              ],
            ),
          ),
        ),
      ),
    );
  }
}

class Hole extends CustomPainter {
  @override
  void paint(Canvas canvas, Size size) {
    canvas.drawCircle(
      Offset(size.width / 2, size.height / 2),
      size.width / 4,
      Paint()
        ..blendMode = BlendMode.xor
        ..color = Colors.yellow,
    );
  }

  @override
  bool shouldRepaint(Hole oldDelegate) => false;
}