import 'dart:async';

class A<X> {
  const A();
}

class Check {
  const Check(x, y)
      : assert(identical(x, y)),
        _ignored = identical(x, y) ? 42 : 1 ~/ 0;
  final _ignored;
}

main() {}
test1() {}
typedef F1 = A<FutureOr<dynamic>> Function();
typedef F2 = A<dynamic> Function();
typedef F3 = A<FutureOr<FutureOr<dynamic>?>> Function();
typedef F4 = A Function();
void expectEqual(x, y) {}