code: def test_task_use_prestarted_worker(call_ray_start):
      ray.init("ray://localhost:50056")
  
      assert (
          len(list_workers(filters=[("worker_type", "!=", "DRIVER")]))
          == 2
      )
  
      @ray.remote(num_cpus=2)
      def f():
          return 42
  
      assert ray.get(f.remote()) == 42
  
      assert (
          len(list_workers(filters=[("worker_type", "!=", "DRIVER")]))
          == 2
      )
  
imports: import os
  import subprocess
  import sys
  import warnings
  from unittest.mock import Mock, patch
  import pytest
  import ray
  import ray.client_builder
  import ray.util.client.server.server
  from ray._private.test_utils import run_string_as_driver, run_string_as_driver_nonblocking, wait_for_condition, skip_flaky_core_test_premerge
  from ray.util.state import list_workers
label_desc: Use image node_id 13 for calling a global function with example usage: test_task_use_prestarted_worker(call_ray_start) and returns: int