code: def test_copy_not_null_rows_cli(tmpdir, synthetic_dataset):
      target_url = "file://" + os.path.join(
          tmpdir.strpath, "copied_data"
      )
  
      _main(
          [
              synthetic_dataset.url,
              target_url,
              "--not-null-fields",
              "string_array_nullable",
          ]
      )
      with make_reader(target_url, num_epochs=1) as reader:
          not_null_data = list(reader)
      assert len(not_null_data) < len(synthetic_dataset.data)
  
file_path: petastorm/petastorm/tests/test_copy_dataset.py
imports: import glob
  import os
  import numpy
  import pytest
  from pyspark.sql import SparkSession
  from pyspark.sql.utils import AnalysisException
  from petastorm.reader import make_reader
  from petastorm.tools.copy_dataset import _main, copy_dataset
label_desc: Use image node_id 4 for calling a global function with example usage: test_copy_not_null_rows_cli(tmpdir, synthetic_dataset) without return types