example1

example1.dart

import 'package:flutter/material.dart';

void main() =>
    runApp(MaterialApp(home: Scaffold(body: Center(child: MyWidget()))));

Future<String> callAsyncFetch() =>
    Future.delayed(Duration(seconds: 3), () => "hi bro !");


class MyWidget extends StatelessWidget {
  @override
  Future<Widget> build(context) async {
    var data = await callAsyncFetch();
    return Text(data);  // doesn't work either
  }
}