code: def check_forward(self, depth_data, space_data):
      depth = chainer.Variable(depth_data)
      d2s = functions.depth2space(depth, self.r)
      d2s_value = cuda.to_cpu(d2s.data)
  
      self.assertEqual(d2s_value.dtype, self.dtype)
      self.assertEqual(d2s_value.shape, (2, 2, 6, 4))
  
      d2s_expect = space_data
  
      testing.assert_allclose(d2s_value, d2s_expect)
  
imports: import unittest
  import numpy
  import chainer
  from chainer.backends import cuda
  from chainer import functions
  from chainer import gradient_check
  from chainer import testing
  from chainer.testing import attr
label_desc: Use image node_id 2 for calling the TestDepth2Space obj's underlying member method code with example usage: obj.check_forward(depth_data, space_data) without return types