if (!val) return;
    if (set_idx) {
      s += ",";
      s += d;
    }
    indent();
    if (name) {
      s += name;
      s += ": ";
    }
  }

  void StartVector() override { s += "[ "; }
  void EndVector() override { s += " ]"; }

  void Element(size_t i, flatbuffers::ElementaryType /*type*/,
               const flatbuffers::TypeTable* /*type_table*/,

    std::string& custom_option_buffer) {
  flexbuffers::Builder fbb;
  size_t start_map = fbb.StartMap();

  auto hash_seed = mlir::dyn_cast_or_null<ArrayAttr>(attrs.get("hash_seed"));
  auto vector_start = fbb.StartVector("hash_seed");
  for (int i = 0; i < hash_seed.size(); i++) {
    fbb.Add(static_cast<int32_t>(
        mlir::dyn_cast<IntegerAttr>(*(hash_seed.getValue().data() + i))
            .getInt()));
  }

        if (attr.list().s_size() > 0) {
          auto start = flex_builder->StartVector(key);
          for (const std::string& v : attr.list().s()) {
            flex_builder->Add(v);
          }
          flex_builder->EndVector(start, /*typed=*/true, /*fixed=*/false);
        } else if (attr.list().i_size() > 0) {
          auto start = flex_builder->StartVector(key);
          for (const int64_t v : attr.list().i()) {