code: def setUp(self) -> None:
      self._params = RendezvousParameters(
          backend="dummy_backend",
          endpoint=self._server.get_endpoint(),
          run_id="dummy_run_id",
          min_nodes=1,
          max_nodes=1,
          protocol="hTTp",
          read_timeout="10",
      )
  
      self._expected_read_timeout = 10
  
imports: import subprocess
  from base64 import b64encode
  from typing import ClassVar, cast
  from unittest import TestCase
  from etcd import EtcdKeyNotFound
  from torch.distributed.elastic.rendezvous import RendezvousConnectionError, RendezvousParameters
  from torch.distributed.elastic.rendezvous.etcd_rendezvous_backend import EtcdRendezvousBackend, create_backend
  from torch.distributed.elastic.rendezvous.etcd_server import EtcdServer
  from torch.distributed.elastic.rendezvous.etcd_store import EtcdStore
  from rendezvous_backend_test import RendezvousBackendTestMixin
label_desc: Use image node_id 3 for calling the CreateBackendTest obj's underlying member method code with example usage: obj.setUp() without return types