code: def _worker_thread_fn(
      host_id, n_jobs, timeout, dbname="foo", logfilename=None
  ):
      mw = MongoWorker(
          mj=TempMongo.mongo_jobs(dbname),
          logfilename=logfilename,
          workdir="mongoexp_test_dir",
      )
      try:
          while n_jobs:
              mw.run_one(host_id, timeout, erase_created_workdir=True)
              print("worker: %s ran job" % str(host_id))
              n_jobs -= 1
      except ReserveTimeout:
          print("worker timed out:", host_id)
          pass
  
imports: import pickle
  import os
  import signal
  import subprocess
  import sys
  import traceback
  import threading
  import time
  import unittest
  import numpy
  import nose
  import nose.plugins.skip
  from hyperopt.base import JOB_STATE_DONE, STATUS_OK
  from hyperopt.mongoexp import parse_url
  from hyperopt.mongoexp import MongoTrials
  from hyperopt.mongoexp import MongoWorker
  from hyperopt.mongoexp import ReserveTimeout
  from hyperopt.mongoexp import as_mongo_str
  from hyperopt.mongoexp import main_worker_helper
  from hyperopt.mongoexp import MongoJobs
  from hyperopt.fmin import fmin
  from hyperopt import hp, rand
  import hyperopt.tests.test_base
  from hyperopt.tests.unit.test_domains import gauss_wave2
label_desc: Use image node_id 4 for calling a global function with example usage: _worker_thread_fn(host_id, n_jobs, timeout, dbname, logfilename) without return types