TypeToken<TwoTypeArgs<?, ?>> supertype = new TypeToken<TwoTypeArgs<?, ?>>() {};
    TypeToken<StringForFirstTypeArg<String>> subtype =
        new TypeToken<StringForFirstTypeArg<String>>() {};
    assertTrue(subtype.isSubtypeOf(supertype));
    assertEquals(
        new TypeToken<StringForFirstTypeArg<?>>() {}, supertype.getSubtype(subtype.getRawType()));
  }