code: def test_pickle(self, pickle_module):
      s = pickle_module.dumps(self.hdfs)
      h2 = pickle_module.loads(s)
      assert h2.is_open
      assert h2.host == self.hdfs.host
      assert h2.port == self.hdfs.port
      assert h2.user == self.hdfs.user
      assert h2.kerb_ticket == self.hdfs.kerb_ticket
      # smoketest unpickled client works
      h2.ls(self.tmp_path)
  
imports: import os
  import random
  from io import BytesIO
  from os.path import join
  import numpy
  import pytest
  import pyarrow
  from pyarrow.tests import util
  from pyarrow.tests.parquet.common import _test_dataframe
  from pyarrow.tests.parquet.test_dataset import _test_write_to_dataset_with_partitions, _test_write_to_dataset_no_partitions
  from pyarrow.util import guid
label_desc: Use image node_id 4 for calling the HdfsTestCases obj's underlying member method code with example usage: obj.test_pickle(pickle_module) without return types