code: def forward(self):
      x = chainer.Variable(self.x)
      return functions.spatial_pyramid_pooling_2d(x, 3, pooling="max")
  
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 2 for calling the TestMaxPooling2DCudnnCall obj's underlying member method code with example usage: obj.forward() and returns: functions