code: def test_im2col_consistency(self):
      col_cpu = conv.im2col_cpu(self.x, 3, 3, 2, 2, 1, 1)
      col_gpu = conv.im2col_gpu(cuda.to_gpu(self.x), 3, 3, 2, 2, 1, 1)
      testing.assert_allclose(col_cpu, col_gpu.get(), atol=0, rtol=0)
  
imports: import unittest
  import numpy
  import pytest
  import six.moves.cPickle
  import chainer
  from chainer.backends import cuda
  from chainer import functions
  from chainer import links
  from chainer import memory_layouts
  from chainer import testing
  from chainer.testing import attr
  from chainer.utils import conv
label_desc: Use image node_id 2 for calling the TestConvolution2DIm2ColConsistency obj's underlying member method code with example usage: obj.test_im2col_consistency() without return types