code: def _Pool_worker(batch_idx, batch):
      # pylint: disable=invalid-name, protected-access
      assert ia.is_single_integer(batch_idx), (
          "Expected `batch_idx` to be an integer. Got type %s instead."
          % (type(batch_idx))
      )
      assert isinstance(batch, (UnnormalizedBatch, Batch)), (
          "Expected `batch` to be either an instance of "
          "`imgaug.augmentables.batches.UnnormalizedBatch` or "
          "`imgaug.augmentables.batches.Batch`. Got type %s instead."
          % (type(batch))
      )
      assert Pool._WORKER_AUGSEQ is not None, (
          "Expected `Pool._WORKER_AUGSEQ` to NOT be `None`. Did you manually "
          "call _Pool_worker()?"
      )
  
      augseq = Pool._WORKER_AUGSEQ
      # TODO why is this if here? _WORKER_SEED_START should always be set?
      if Pool._WORKER_SEED_START is not None:
          seed = Pool._WORKER_SEED_START + batch_idx
          _reseed_global_local(seed, augseq)
      result = augseq.augment_batch_(batch)
      return result
  
imports: from __future__ import print_function, division, absolute_import
  import sys
  import multiprocessing
  import threading
  import traceback
  import time
  import random
  import platform
  import numpy
  import cv2
  import imgaug.imgaug
  import imgaug.random
  from imgaug.augmentables.batches import Batch, UnnormalizedBatch
label_desc: Use image node_id 8 for calling a global function with example usage: _Pool_worker(batch_idx, batch) and returns: result