Iterable<? extends TypeToken<?>> types) {
    int i = 0;
    for (TypeToken<?> left : types) {
      int j = 0;
      for (TypeToken<?> right : types) {
        if (left.isSupertypeOf(right)) {
          assertTrue(left + " should be after " + right, i >= j);
        }
        j++;
      }
      i++;
    }
  }