code: def add_one(self, x):
      return x + 1
  
imports: import random
  import unittest
  import parl
  import numpy
  from parl.remote.client import disconnect
  from parl.utils import logger, get_free_tcp_port
  from parl.remote.master import Master
  from parl.remote.worker import Worker
  import time
  import threading
  import random
  from parl.utils.test_utils import XparlTestCase
label_desc: Use image node_id 2 for calling the Actor1 obj's underlying member method code with example usage: obj.add_one(x) and returns: unknown