crashlytics flutter

wrapper.dart

import 'package:firebase_crashlytics/firebase_crashlytics.dart';
import 'package:flutter/material.dart';
import 'package:firebase_core/firebase_core.dart';

class Wrapper extends StatefulWidget {
  // This widget is the root of your application.
  @override
  _WrapperState createState() => _WrapperState();
}

class _WrapperState extends State<Wrapper> {

  Future<void> _initializeFuture;

  //init firebase crashlytics
  Future<void> _initializeFlutterFire() async {
    await Firebase.initializeApp();
    //Force enable crashlytics collection enabled for debugging.
    await FirebaseCrashlytics.instance.setCrashlyticsCollectionEnabled(true);
    // Pass all uncaught errors to Crashlytics.
    Function originalOnError = FlutterError.onError;
    FlutterError.onError = (FlutterErrorDetails errorDetails) async {
      await FirebaseCrashlytics.instance.recordFlutterError(errorDetails);
      // Forward to original handler.
      originalOnError(errorDetails);
    };
  }

  @override
  void initState() {
    super.initState();
    _initializeFuture = _initializeFlutterFire();
  }

  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      debugShowCheckedModeBanner: false,
      theme: ThemeData(
        primarySwatch: Colors.blue,
        visualDensity: VisualDensity.adaptivePlatformDensity,
      ),
      home: Scaffold(
        body: FutureBuilder(
          future: _initializeFuture,
          builder: (context, snapshot) {
            switch (snapshot.connectionState) {
              case ConnectionState.done:
                return DemoApp(
                  ....
                  ....
                  ....
                );
                break;
              default:
                return Center(
                  child: Text('Loading...'),
                );
            }
          },
        ),
      ),
    );
  }
}