code: def test_pax_format():
      num_samples = 1000
      tar_file_path = os.path.join(
          get_dali_extra_path(), "db/webdataset/MNIST/devel-0.tar"
      )
      pax_tar_file_path = os.path.join(
          get_dali_extra_path(), "db/webdataset/pax/devel-0.tar"
      )
      index_file = generate_temp_index_file(tar_file_path)
  
      num_shards = 100
      for shard_id in range(num_shards):
          compare_pipelines(
              webdataset_raw_pipeline(
                  tar_file_path,
                  index_file.name,
                  ["jpg", "cls"],
                  num_shards=num_shards,
                  shard_id=shard_id,
                  batch_size=test_batch_size,
                  device_id=0,
                  num_threads=1,
              ),
              webdataset_raw_pipeline(
                  pax_tar_file_path,
                  None,
                  ext=["jpg", "cls"],
                  num_shards=num_shards,
                  shard_id=shard_id,
                  batch_size=test_batch_size,
                  device_id=0,
                  num_threads=1,
              ),
              test_batch_size,
              math.ceil(num_samples / num_shards / test_batch_size) * 2,
          )
  
imports: import os
  from glob import glob
  import math
  import nvidia.dali
  from test_utils import compare_pipelines, get_dali_extra_path
  from nose_utils import assert_raises
  from nose.tools import assert_equal
  from webdataset_base import generate_temp_extract, generate_temp_index_file, webdataset_raw_pipeline, file_reader_pipeline
  from webdataset_base import test_batch_size
label_desc: Use image node_id 8 for calling a global function with example usage: test_pax_format() without return types