code: def test_initialize_workers(self):
      spec = self._get_worker_spec(max_restarts=1)
      agent = TestAgent(spec)
      worker_group = agent.get_worker_group()
      agent._initialize_workers(worker_group)
  
      self.assertEqual(WorkerState.HEALTHY, worker_group.state)
      for i in range(spec.local_world_size):
          worker = worker_group.workers[i]
          self.assertEqual(worker.id, worker.global_rank)
  
imports: import signal
  import unittest
  import uuid
  from typing import Any, Dict
  from unittest.mock import call, patch, MagicMock
  import torch.distributed.elastic.rendezvous.registry
  from torch.distributed.elastic.agent.server.api import RunResult, SimpleElasticAgent, WorkerGroup, WorkerSpec, WorkerState, _get_fq_hostname, _RoleInstanceInfo
  from torch.distributed.elastic.multiprocessing import SignalException
  from torch.distributed.elastic.multiprocessing.errors import ProcessFailure
  from torch.distributed.elastic.rendezvous import RendezvousHandler, RendezvousParameters
  from torch.distributed.elastic.utils.distributed import get_free_port
  from torch.testing._internal.common_utils import run_tests
label_desc: Use image node_id 15 for calling the SimpleElasticAgentTest obj's underlying member method code with example usage: obj.test_initialize_workers() without return types