code: def test_ray_init_using_hostname(ray_start_cluster):
      import socket
  
      hostname = socket.gethostname()
      cluster = Cluster(
          initialize_head=True,
          head_node_args={
              "node_ip_address": hostname,
          },
      )
  
      # Use `ray.init` to test the connection.
      ray.init(address=cluster.address, _node_ip_address=hostname)
  
      node_table = cluster.global_state.node_table()
      assert len(node_table) == 1
      assert node_table[0].get("NodeManagerHostname", "") == hostname
  
imports: import os
  import sys
  import unittest.mock
  import signal
  import subprocess
  import grpc
  import pytest
  import ray
  import ray._private.services
  from ray.client_builder import ClientContext
  from ray.cluster_utils import Cluster
  from ray.util.client.common import ClientObjectRef
  from ray.util.client.ray_client_helpers import ray_start_client_server
  from ray.util.client.worker import Worker
  from ray._private.test_utils import wait_for_condition, enable_external_redis
label_desc: Use image node_id 10 for calling a global function with example usage: test_ray_init_using_hostname(ray_start_cluster) without return types