code: def forward(self, inputs, device):
      (x,) = inputs
      y = functions.max_pooling_2d(
          x, 3, stride=2, pad=1, cover_all=self.cover_all
      )
      return (y,)
  
imports: import unittest
  import numpy
  import six
  import chainer
  from chainer.backends import cuda
  from chainer import functions
  from chainer import testing
  from chainer.testing import attr
  from chainer.testing import backend
  from chainer_tests.functions_tests.pooling_tests import pooling_nd_helper
label_desc: Use image node_id 4 for calling the TestMaxPooling2D obj's underlying member method code with example usage: obj.forward(inputs, device) and returns: y