Hero calls initState three times

main.dart

import 'package:flutter/material.dart';

main() {
  runApp(MaterialApp(home: const Page()));
}

class Page extends StatelessWidget {
  const Page({Key key}) : super(key: key);

  @override
  Widget build(BuildContext context) => WillPopScope(
        onWillPop: () async {
          initStateCalled = 0;
          return true;
        },
        child: Scaffold(
            body: Stack(children: [
          Hero(tag: 'tag', child: HeroContent()),
          Center(
            child: FlatButton(
              child: const Text('navigate'),
              onPressed: () {
                initStateCalled = 0;
                Navigator.of(context).push(MaterialPageRoute(builder: (_) => const Page()));
              },
            ),
          ),
          Align(
            alignment: Alignment.bottomCenter,
            child: FlatButton(
              child: const Text('back'),
              onPressed: () {
                Navigator.of(context).maybePop();
              },
            ),
          )
        ])),
      );
}

int initStateCalled = 0;

class HeroContent extends StatefulWidget {
  HeroContent({Key key}) : super(key: key);

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

class _HeroContentState extends State<HeroContent> {
  @override
  void initState() {
    print('initState called: ${++initStateCalled}');
    super.initState();
  }

  @override
  Widget build(BuildContext context) => Container();
}