code: def test_backward_cpu(self):
      x_shape = (self.n_batches, self.in_channels, 10, 10)
      w_shape = (self.in_channels, self.out_channels, 5, 5)
      x = numpy.ones(x_shape, numpy.float32)
      w = numpy.ones(w_shape, numpy.float32)
      b = numpy.ones(self.out_channels, numpy.float32)
      with chainer.using_config("use_ideep", "never"):
          self.check_backward_succeed(x, w, b)
  
imports: import unittest
  import numpy
  import chainer
  from chainer.backends import cuda
  import chainer.functions
  from chainer import testing
  from chainer.testing import array
  from chainer.testing import attr
  from chainer.testing import parameterize
  from chainer.utils import conv
label_desc: Use image node_id 2 for calling the TestDeconvolution2DVariousGradTargets obj's underlying member method code with example usage: obj.test_backward_cpu() without return types