code: def test_set_state_sets_backend_state_if_token_is_current(
      self,
  ) -> None:
      state1, token1, has_set1 = self._set_state(b"x")
  
      state2, token2, has_set2 = self._set_state(b"y", token1)
  
      self.assertEqual(b"y", state2)
      self.assertNotEqual(token1, token2)
      self.assertTrue(has_set1)
      self.assertTrue(has_set2)
  
file_path: pytorch/test/distributed/elastic/rendezvous/rendezvous_backend_test.py
imports: from abc import ABC, abstractmethod
  from typing import Any, Callable, Optional, Tuple, cast
  from torch.distributed.elastic.rendezvous import RendezvousStateError
  from torch.distributed.elastic.rendezvous.dynamic_rendezvous import RendezvousBackend, Token
label_desc: Use image node_id 7 for calling the RendezvousBackendTestMixin obj's underlying member method code with example usage: obj.test_set_state_sets_backend_state_if_token_is_current() without return types