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

  LogicalResult RewriteFunc();

  LogicalResult VerifySignature();

 private:
  LogicalResult CreateCustomOptions(std::string& custom_option_buffer);

  func::FuncOp func_;
  mlir::TF::FuncAttr attr_;
};

// Fuse DenseImageWarp ops annotated by tf.function to a TFLite custom op.
class ConvertDenseImageWarpFunc {

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

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