reference 0.4.2+1

Reduce plugin maintenance burden for plugins that have to maintain platform object instances in memory.

example/lib/main.dart

import 'package:flutter/material.dart';

void main() {
  runApp(const _MyApp());
}

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

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

class _MyAppState extends State<_MyApp> {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      home: Scaffold(
        appBar: AppBar(
          title: const Text('Plugin example app'),
        ),
        body: Center(
          child: ElevatedButton(
            onPressed: () {
              debugPrint('HI!');
            },
            child: const Text('HI'),
          ),
        ),
      ),
    );
  }
}