std::vector<int> v(attr.minimum());
      for (int i = 0; i < v.size(); ++i) v[i] = i;
      std::string s = strings::StrCat("{", absl::StrJoin(v, ","), "}");
      return s;
    }
  }
  if (attr.has_allowed_values()) {
    if (!attr.allowed_values().list().s().empty()) {
      return strings::StrCat("\"", attr.allowed_values().list().s(0), "\"");
    } else if (!attr.allowed_values().list().type().empty()) {