code: def test_sp_is_worker():
      pid, w, mpw = run_sp(_worker_status, "fishtank")
      assert pid != os.getpid()
      assert w
      assert not mpw
  
imports: import os
  import logging
  import multiprocessing
  import numpy
  import pytest
  from seedbank import root_seed
  from lenskit.util.parallel import invoker, proc_count, run_sp, is_worker, is_mp_worker
  from lenskit.util.test import set_env_var
  from lenskit.sharing import persist, SHM_AVAILABLE
  from pytest import mark, raises, approx
label_desc: Use image node_id 15 for calling a global function with example usage: test_sp_is_worker() without return types