code: def test_ray_stop_should_not_kill_external_redis(redis_proc):
      check_call_ray(["start", "--head"])
      subprocess.check_call(["ray", "stop"])
      assert redis_proc.poll() is None
  
imports: import asyncio
  import os
  import subprocess
  import sys
  from pathlib import Path
  import psutil
  import pytest
  import ray
  import ray._private.ray_constants
  from ray._private.test_utils import Semaphore, check_call_ray, check_call_subprocess, kill_process_by_name, start_redis_instance, run_string_as_driver, run_string_as_driver_nonblocking, wait_for_children_of_pid, wait_for_children_of_pid_to_exit
  from ray._private.utils import detect_fate_sharing_support
label_desc: Use image node_id 9 for calling a global function with example usage: test_ray_stop_should_not_kill_external_redis(redis_proc) without return types