main.dart

void main() async {
  methodA(1);

  methodB('non'); //намеренно вызвано без await
  methodA(2);

  Future(() {
    print('Future 1');
  });
  
  await methodB('await');
  
  Future(() {
    print('Future 2');
  });
  methodA(3);
}

methodA(n) {
  print('A $n');
}

methodB(n) async {
  print('B start from $n');

  Future(() {
    print('Future B non await from $n');
  });
  await Future(() {
    print('Future B from $n');
  });

  print('B end from $n');
  await Future(() {
    print('Future B2 form $n');
  });
}