for (auto msubgraph : *mutable_subgraphs) {
    auto operators = msubgraph->mutable_operators();
    for (auto op : *operators) {
      auto opcode_idx = op->opcode_index();
      auto opcodes = mutable_model->operator_codes();
      auto opcode = (*opcodes)[opcode_idx]->builtin_code();
      if (opcode == tflite::BuiltinOperator_CUSTOM) {
        std::vector<int32_t> inputs(op->inputs()->begin(), op->inputs()->end());