final class A<reify T> {}

class B<reify T> {}
final class C<reify Ti, reify To> extends B<Ti> {}

<<__EntryPoint>>
function m(): void {

  require_once __DIR__.'/vendor/autoload.hack';
  \Facebook\AutoloadMap\initialize();

  echo \Facebook\TypeSpec\of<C<string, A<int>>>()->toString();
}