const Model* output_model = GetModel(buffer);
  ASSERT_TRUE(output_model);

  for (size_t subgraph_idx = 0; subgraph_idx < model_->subgraphs()->size();
       subgraph_idx++) {
    const auto quantized_graph = output_model->subgraphs()->Get(subgraph_idx);
    const auto float_graph = model_->subgraphs()->Get(subgraph_idx);
    ASSERT_EQ(quantized_graph->tensors()->size(),
              float_graph->tensors()->size());

  ASSERT_THAT(model.subgraphs, SizeIs(expected_model.subgraphs.size()));
  for (size_t subgraph_idx = 0; subgraph_idx < model.subgraphs.size();
       subgraph_idx++) {
    const auto graph = model.subgraphs[subgraph_idx].get();
    const auto expected_graph = expected_model.subgraphs[subgraph_idx].get();
    for (auto& op : graph->operators) {
      for (int idx = 0; idx < op->inputs.size(); idx++) {

    uint32_t subgraph_idx = opts->update_computation_subgraph_index;

    if (subgraph_idx >= func_names.size()) {
      return absl::AbortedError(
          absl::StrCat("subgraph with index not found: ", subgraph_idx));
    }
    mlir::FlatSymbolRefAttr subgraph_attr = mlir::SymbolRefAttr::get(
        builder.getContext(), func_names.at(subgraph_idx));

  // the entry functions at the beginning of the subgraph list and the
  // subgraph_index is the index in entry functions and at the same, is the
  // index in the subgraph list.
  int subgraph_index = 0;
  for (const auto& signature_def_data : signature_defs) {
    auto inputs = GetList(subgraph_index, signature_def_data.inputs);
    auto outputs = GetList(subgraph_index, signature_def_data.outputs);

      TypesFromValues(subgraph.FuncOutputs());

  FunctionType function_type =
      builder.getFunctionType(input_types, return_types);

  std::string function_name = absl::StrCat("func_", subgraph.subgraph_id_);

  func::FuncOp new_func = func::FuncOp::create(builder.getUnknownLoc(),
                                               function_name, function_type);
  new_func.setVisibility(func::FuncOp::Visibility::Private);

    fbb_.AddOffset(SignatureDef::VT_SIGNATURE_KEY, signature_key);
  }
  void add_subgraph_index(uint32_t subgraph_index) {
    fbb_.AddElement<uint32_t>(SignatureDef::VT_SUBGRAPH_INDEX, subgraph_index, 0);
  }
  explicit SignatureDefBuilder(::flatbuffers::FlatBufferBuilder &_fbb)
        : fbb_(_fbb) {
    start_ = fbb_.StartTable();
  }