code: def setUp(self):
      self.N = 2
      self.n_channels = 3
      inh, inw = 2, 1
      self.x = pooling_nd_helper.shuffled_linspace(
          (self.N, self.n_channels, inh, inw), self.dtype
      )
  
      self.ksize = 2
      outh, outw = self.outsize or self.expected_outsize
      self.gy = numpy.random.uniform(
          -1, 1, (self.N, self.n_channels, outh, outw)
      ).astype(self.dtype)
      self.check_backward_options = {"atol": 1e-4, "rtol": 1e-3}
      self.check_double_backward_options = {}
      if self.dtype == numpy.float16:
          self.check_backward_options = {"atol": 2e-3, "rtol": 2e-2}
          self.check_double_backward_options = {
              "atol": 3e-3,
              "rtol": 3e-2,
          }
      self.ggx = numpy.random.uniform(-1, 1, self.x.shape).astype(
          self.dtype
      )
  
imports: import unittest
  import numpy
  import six
  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
  from chainer_tests.functions_tests.pooling_tests import pooling_nd_helper
label_desc: Use image node_id 1 for calling the TestUnpooling2D obj's underlying member method code with example usage: obj.setUp() without return types