typedef T Func<T>();

class Foo<S> {
  m(x) => x is Func<S>;
}

class Bar<T> {
  f() {
    T local() {}
    return local;
  }
}

void main() {
  var x = new Foo<List<String>>();
  if (new DateTime.now().millisecondsSinceEpoch == 42) x = new Foo<int>();
  print(x.m(new Bar<String>().f()));
  print(x.m(new Bar<List<String>>().f()));
}