func_->setAttr(kTFImplements,
                 StringAttr::get(func_.getContext(), kCustomSSDPostprocessing));

  OpBuilder builder(func_.getBody());
  std::string custom_option_buffer;
  if (failed(CreateNMSCustomOptions(func_, attr_.getAttrs(),
                                    custom_option_buffer))) {
    return failure();
  }
  auto op = builder.create<CustomOp>(
      func_.getLoc(), func_.getFunctionType().getResults(),

      : func_(func), attr_(attr) {}

  LogicalResult RewriteFunc();

  LogicalResult VerifySignature();

 private:
  LogicalResult CreateNMSCustomOptions(func::FuncOp func, DictionaryAttr attrs,
                                       std::string& custom_option_buffer);

  LogicalResult AddIntAttr(func::FuncOp func, DictionaryAttr attrs,