message: Add "ret" stuff to the function def. Okay, NOW they should be valid. :)
diff: @@ -172,10 +172,16 @@ private:
  std::stringstream ss;
  ss << "ngraph_output_" << cluster_output_dt_map[src_cluster_idx].size();
  + string output_name = ss.str();
  +
  auto new_output_arg = fdef_map[src_cluster_idx].mutable_signature()->add_output_arg();
  - new_output_arg->set_name(ss.str());
  + new_output_arg->set_name(output_name);
  new_output_arg->set_type(dt);
  + std::stringstream ss_ret;
  + ss_ret << src->name() << ":" << edge->src_output();
  + (*(fdef_map[src_cluster_idx].mutable_ret()))[output_name] = ss_ret.str();
  +
  std::stringstream ss_desc;
  ss_desc << "Output replacing " << src->name() << ":" << edge->src_output();
  new_output_arg->set_description(ss_desc.str());
  