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()));
  }