message: Remove redundant conversion to std::string
diff: @@ -14,7 +14,7 @@ bool EngineResponseRecord::operator==(const ModelType &rhs) const {
  std::string EngineResponseRecord::toString() const {
  return detail::PrettyStringBuilder()
  .init("EngineResponseRecord")
  - .appendNamed("command_index", std::to_string(commandIndex()))
  + .appendNamed("command_index", commandIndex())
  .appendNamed("reponse", response())
  .finalize();
  }
  