code: def test_parse_rendezvous_returns_empty_dict_if_str_is_empty(
      self,
  ) -> None:
      config_strs = ["", "   "]
  
      for config_str in config_strs:
          with self.subTest(config_str=config_str):
              config = _parse_rendezvous_config(config_str)
  
              self.assertEqual(config, {})
  
imports: import threading
  import time
  import socket
  from datetime import timedelta
  from typing import List
  from unittest import TestCase
  from unittest.mock import patch
  from torch.distributed.elastic.rendezvous.utils import _PeriodicTimer, _delay, _matches_machine_hostname, _parse_rendezvous_config, _try_parse_port, parse_rendezvous_endpoint
label_desc: Use image node_id 2 for calling the UtilsTest obj's underlying member method code with example usage: obj.test_parse_rendezvous_returns_empty_dict_if_str_is_empty() without return types