final String _privateData;

void _doExample() {}

// файл parent.dart

class Parent {
  @protected
  void doProtected() {}
}
...
// файл child.dart

class Child extends Parent {
  void doExample() {
    doProtected(); // допустимо
  }
}

void main() {
  final parent = Parent();

  parent.doProtected(); // вызывает предупреждение анализатора
}

// файл lib/parent.dart

class Parent {
  @visibleForTesting
  void doExample() {}
}
...
// файл lib/main.dart

void main() {
  final parent = Parent();
  parent.doExample(); // вызывает предупреждение анализатора invalid_use_of_visible_for_testing_member
}
...
// файл test/parent_test.dart

void main() {
  test('Тестируем @visibleForTesting', () {
    final test = Parent();
    test.doExample(); // допустимо
  });
}

flutter:
  assets:
    - path: assets/web_worker.js
      platforms: [web]
    - path: assets/desktop_icon.png
      platforms: [windows, linux, macos]

Future<void> main() async {
  final connectivity = Connectivity();

  final connectionsList = await connectivity.checkConnectivity();
  print(connectionsList);
}

Future<void> main() async {
  final hasConnection = await InternetConnectionChecker.instance.hasConnection;
  print(hasConnection);
}

Future<void> main() async {
  final customChecker = InternetConnectionChecker.createInstance(
    addresses: [AddressCheckOption(uri: Uri.parse('custom_resource'))],
  );
  final hasConnection = await customChecker.hasConnection;

  print(hasConnection);
}

Future<void> main() async {
  final networkInfo = NetworkInfo();
  
  print(networkInfo.getWifiName());
  print(networkInfo.getWifiIP());
  print(networkInfo.getWifiIPv6());
  print(networkInfo.getWifiBroadcast());
  print(networkInfo.getWifiBSSID());
}

flutter:
  fonts:
    - family: Montserrat
      fonts:
        - asset: fonts/Montserrat-Regular.ttf
        - asset: fonts/Montserrat-Bold.ttf
          weight: 700

Text(
  'Привет, Flutter!',
  style: TextStyle(
    fontFamily: 'Montserrat',
    fontSize: 24,
    fontWeight: FontWeight.bold,
  ),
)

MaterialApp(
  theme: ThemeData(
    fontFamily: 'Montserrat',
  ),
  home: MyHomePage(),
)

Text(
  'Привет, Flutter!',
  style: GoogleFonts.montserrat(
    fontSize: 24,
    fontWeight: FontWeight.bold,
  ),
)

@protected
void setState(VoidCallback fn) {
   ...
   _element!.markNeedsBuild();
}

void markNeedsBuild() {
  ...  
  if (dirty) {
    return;
  }
  _dirty = true;
  owner!.scheduleBuildFor(this);
}

@override
Widget build(BuildContext context) {
  return Container(
    child: Text('Привет'),
  );
}

final theme = Theme.of(context);

Navigator.of(context).push(
  MaterialPageRoute(builder: (context) => NextScreen()),
);

@override
Widget build(BuildContext context) {
  Future.delayed(Duration(seconds: 2), () {
    // Опасно! Context может быть уже невалидным
    showDialog(context: context, builder: (_) => AlertDialog());
  });
  return Container();
}

final data = MyInheritedWidget.of(context);

import 'package:flutter/material.dart';

class ItemWidget extends StatefulWidget {
  final String title;
  ItemWidget(this.title);

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

class _ItemWidgetState extends State<ItemWidget> {
  int counter = 0;

  @override
  Widget build(BuildContext context) {
    return ListTile(
      title: Text('${widget.title} ($counter)'),
      trailing: IconButton(
        icon: Icon(Icons.add),
        onPressed: () => setState(() => counter++),
      ),
    );
  }
}

final localAuth = LocalAuthentication();

final isDeviceSupported = await localAuth.isDeviceSupported();
final canAuthenticate = await localAuth.canCheckBiometrics;

final list = await localAuth.getAvailableBiometrics();

final successAuth = await localAuth.authenticate(
   localizedReason: 'ВОЙДИТЕ',
   biometricOnly: true,
);

late StreamSubscription<AccelerometerEvent> _accelerometerSubscription;
...
_accelerometerSubscription = accelerometerEventStream().listen((event) {
    print('x: ${event.x}, y: ${event.y}, z: ${event.z}');
  });

_accelerometerSubscription.cancel();