code: def return_arg(self, arg):
      return arg
  
file_path: ray/python/ray/tests/test_actor_group.py
imports: import time
  import warnings
  import pytest
  import ray
  from ray.util.actor_group import ActorGroup
label_desc: Use image node_id 1 for calling the DummyActor obj's underlying member method code with example usage: obj.return_arg(arg) and returns: arg