code: def setUp(self):
      if (
          self.iterator_class == chainer.iterators.MultiprocessIterator
          and int(platform.python_version_tuple()[0]) < 3
      ):
          pytest.skip("This test requires Python version >= 3")
      self.communicator = chainermn.create_communicator("naive")
  
      if self.communicator.size < 2:
          pytest.skip("This test is for multinode only")
  
      self.N = 6
      self.dataset = numpy.arange(self.N).astype(numpy.float32)
      self.bs = 2
  
imports: import numpy
  import platform
  import pytest
  import unittest
  import chainer
  import chainer.testing
  import chainermn
label_desc: Use image node_id 1 for calling the TestIteratorCompatibility obj's underlying member method code with example usage: obj.setUp() without return types