foo<T extends Object?, S extends List<T>>(T t) => null;
bar<T extends Object?, S extends List<T?>>(T t) => null;
baz(int? x, int y) {}

class A<T extends Object?, S extends Object> {
  hest<X extends T, Y extends List<X>, Z extends List<X?>>() => null;
  fisk<X extends S, Y extends List<X>, Z extends List<X?>>() => null;
  mus<X extends Object?, Y extends List<X>, Z extends List<X?>>() => null;
}

main() {}