code: def setUp(self):
      self.x = numpy.random.randn(5, 3, 5, 5)
      self.v = chainer.Variable(self.x.astype(numpy.float32))
  
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
  from chainer.testing import condition
  from chainer.utils import type_check
  from chainer_tests.functions_tests.pooling_tests import pooling_nd_helper
label_desc: Use image node_id 1 for calling the TestInvalidArguments obj's underlying member method code with example usage: obj.setUp() without return types