message: removed unused return value spam; also why were objects passed by value
diff: @@ -74,12 +74,11 @@ static tf::Status ValidateInputCountMin(const tf::Node* op, size_t count) {
  // shared_ptr<ng::Node> output_node - ng::Node to store
  //
  -static tf::Status SaveNgOp(Builder::OpMap& ng_op_map, const std::string op_name,
  - const shared_ptr<ng::Node> output_node) {
  +static void SaveNgOp(Builder::OpMap& ng_op_map, const std::string& op_name,
  + const shared_ptr<ng::Node>& output_node) {
  // no need to try-catch, map[key] will create vector object
  // if not exists
  ng_op_map[op_name].push_back(output_node);
  - return tf::Status::OK();
  }
  // Helper for fetching correct input node from ng_op_map.
  