CreateOpMetadata(
          fb_builder, 3, 1,
          fb_builder.CreateVector(std::vector<float>({-1.0, 2.0}))),
  };
  const auto subgraphs = {CreateSubgraphMetadata(
      fb_builder, fb_builder.CreateVector(ops.begin(), ops.size()))};

  const auto metadata = CreateRuntimeMetadata(
      fb_builder, hardwares,
      fb_builder.CreateVector(subgraphs.begin(), subgraphs.size()));

      flatbuffers::Offset<flatbuffers::Vector<float>> per_device_cost_offset;

      if (per_device_cost.has_value()) {
        per_device_cost_offset = builder->CreateVector(*per_device_cost);
      }

      OpMetadataBuilder op_builder(*builder);
      op_builder.add_index(index);
      uint8_t hardware = hardware_map.at(*device_name);
      op_builder.add_hardware(hardware);