code: def setUp(self):
      self.io = io.BytesIO()
  
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 1 for calling the TestPickleDataset obj's underlying member method code with example usage: obj.setUp() without return types