code: def test_rank(self) -> None:
      ranks = test_rank_func()
      self.assertEqual(ranks, [0, 1])
  
imports: import unittest
  import crypten
  import crypten.communicator
  import crypten.mpc
  import torch
  from crypten.config import cfg
label_desc: Use image node_id 1 for calling the TestContext obj's underlying member method code with example usage: obj.test_rank() without return types