code: def test_redis_tls(setup_tls, setup_replicas, ray_start_cluster_head):
      @ray.remote
      def hello():
          return "world"
  
      assert ray.get(hello.remote()) == "world"
  
imports: import pytest
  import sys
  import ray
  from ray._private.test_utils import enable_external_redis
label_desc: Use image node_id 3 for calling a global function with example usage: test_redis_tls(setup_tls, setup_replicas, ray_start_cluster_head) and returns: str