code: def check_im2col(self, kh, kw, sy, sx, ph, pw, dy, dx, gpu):
      if gpu:
          img = cuda.to_gpu(self.img)
      else:
          img = self.img
  
      col = conv.im2col(img, kh, kw, sy, sx, ph, pw, dy=dy, dx=dx)
      col_h = conv.get_conv_outsize(self.h, kh, sy, ph, d=dy)
      col_w = conv.get_conv_outsize(self.w, kw, sx, pw, d=dx)
      self.assertEqual(col.shape, (2, 3, kh, kw, col_h, col_w))
  
      col = cuda.to_cpu(col)
  
      for y in moves.range(col_h):
          for x in moves.range(col_w):
              for ky in moves.range(kh):
                  for kx in moves.range(kw):
                      oy = y * sy - ph + ky * dy
                      ox = x * sx - pw + kx * dx
                      if 0 <= oy < self.h and 0 <= ox < self.w:
                          testing.assert_allclose(
                              col[:, :, ky, kx, y, x],
                              self.img[:, :, oy, ox],
                          )
                      else:
                          testing.assert_allclose(
                              col[:, :, ky, kx, y, x],
                              numpy.zeros((2, 3), self.dtype),
                          )
  
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 2 for calling the TestIm2Col obj's underlying member method code with example usage: obj.check_im2col(kh, kw, sy, sx, ph, pw, dy, dx, gpu) without return types