code: def simple_func(tensor):
      return tensor
  
imports: import multiprocessing
  import os
  import socket
  import time
  import unittest
  import backend
  import dgl
  import pytest
  from numpy.testing import assert_array_equal
  from utils import generate_ip_config, reset_envs
label_desc: Use image node_id 2 for calling a global function with example usage: simple_func(tensor) and returns: tensor