code: def test_col2im_gpu(self):
      self.check_col2im(*self.params, gpu=True)
  
imports: import unittest
  import numpy
  from six import moves
  from chainer.backends import cuda
  from chainer import testing
  from chainer.testing import attr
  from chainer.utils import conv
label_desc: Use image node_id 4 for calling the TestCol2Im obj's underlying member method code with example usage: obj.test_col2im_gpu() without return types