code: def test_ray_init_no_local_instance(shutdown_only, address):
      # Starts a new Ray instance.
      if address is None:
          ray.init(address=address)
      else:
          # Throws an error if we explicitly want to connect to an existing
          # instance and none exists.
          with pytest.raises(ConnectionError):
              ray.init(address=address)
  
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 2 for calling a global function with example usage: test_ray_init_no_local_instance(shutdown_only, address) without return types