// Builds and returns list of tfl.SignatureDef sections in the model.
  std::optional<VectorBufferOffset<BufferOffset<tflite::SignatureDef>>>
  CreateSignatureDefs(const std::vector<SignatureDefData>& signature_defs);

  // Returns list of offsets for the passed 'items' in TensorMap structure
  // inside the flatbuffer.
  // 'items' is a map from tensor name in signatureDef to tensor name in

  // Find the FuncOp which corresponds to current SignatureDef.
  mlir::SymbolTable sub_symbol_table(*sub_module);
  auto func_op = sub_symbol_table.lookup<mlir::func::FuncOp>(sig_def_key);
  TF_RET_CHECK(func_op)
      << "Graphdef importer should have created a function named "
      << sig_def_key << ".";

  // Use unique SignatureDef key as exported name.
  func_op->setAttr(kTfSavedModelExportedNamesAttr,