Method initialize

examples/t08_additional_node_args.cpp:69–73

we want this method to be called ONCE and BEFORE the first tick()

  // we want this method to be called ONCE and BEFORE the first tick()
  void initialize(int arg_int, std::string arg_str)
  {
    _arg1 = (arg_int);
    _arg2 = (arg_str);
  }

  NodeStatus tick() override
  {