code: def setUp(self):
      self.list_of_node_ips = ["0.0.0.0:1", "0.0.0.0:2"]
      self.host, self.port = (
          socket.gethostbyname(socket.gethostname()),
          1234,
      )
      self.server = OnPremCoordinatorServer(
          list_of_node_ips=self.list_of_node_ips,
          host=self.host,
          port=self.port,
      )
      self.coordinator_address = self.host + ":" + str(self.port)
  
imports: import os
  import random
  import unittest
  import socket
  import json
  from ray.autoscaler.local.coordinator_server import OnPremCoordinatorServer
  from ray.autoscaler._private.providers import _NODE_PROVIDERS, _get_node_provider
  from ray.autoscaler._private.local import config
  from ray.autoscaler._private.local.node_provider import LocalNodeProvider
  from ray.autoscaler._private.local.node_provider import record_local_head_state_if_needed
  from ray.autoscaler._private.local.coordinator_node_provider import CoordinatorSenderNodeProvider
  from ray.autoscaler.tags import TAG_RAY_NODE_KIND, TAG_RAY_CLUSTER_NAME, TAG_RAY_NODE_NAME, NODE_KIND_WORKER, NODE_KIND_HEAD, TAG_RAY_USER_NODE_TYPE, TAG_RAY_NODE_STATUS, STATUS_UP_TO_DATE
  from ray._private.utils import get_ray_temp_dir
  import pytest
label_desc: Use image node_id 1 for calling the OnPremCoordinatorServerTest obj's underlying member method code with example usage: obj.setUp() without return types