for (auto* abstract_output : outputs->outputs) {
      GraphTensor* output = dyn_cast<GraphTensor>(abstract_output);
      if (!output) {
        return errors::Unimplemented(
            "Returning a non-graph tensor from a function has not "
            "been implemented yet.");
      }
      graph_outputs.push_back(output->output_);
    }

    auto s = TF_NewStatus();