import 'package:flutter/cupertino.dart';
import 'package:flutter/material.dart';

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

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return const MaterialApp(title: 'Test App Demo', home: _Page());
  }
}

class _Page extends StatefulWidget {
  const _Page({Key? key}) : super(key: key);

  @override
  _PageState createState() => _PageState();
}

class _PageState extends State<_Page> {
  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(title: Text('$hashCode')),
      body: Center(
        child: TextButton(
          onPressed: () {
            Navigator.of(context).push<void>(
              CupertinoPageRoute<void>(builder: (_) => const _Page()),
            );
          },
          child: const Text('Test push'),
        ),
      ),
    );
  }
}