import 'dart:async';

typedef G<T> = dynamic Function<S extends T>(S);

typedef H<T> = dynamic Function<S extends FutureOr<T>>(S, FutureOr<T>);

class C<T> {
  G<T> field1;
  H<T> field2;
  C(this.field1, this.field2);
}

test1(C<num> c) {}

test2(C<num?> c) {}

test3<S extends num?>(S s) => s + 1;

main() {}