code: def test_write_read(self):
      with datasets.open_pickle_dataset_writer(self.path) as writer:
          writer.write(1)
  
      with datasets.open_pickle_dataset(self.path) as dataset:
          assert dataset[0] == 1
  
imports: import ctypes
  import io
  import multiprocessing
  import os
  import pickle
  import platform
  import sys
  import unittest
  import mock
  from chainer import datasets
  from chainer.datasets import pickle_dataset
  from chainer import testing
  from chainer import utils
label_desc: Use image node_id 3 for calling the TestPickleDatasetHelper obj's underlying member method code with example usage: obj.test_write_read() without return types