code: def test_double_backward_gpu_no_cudnn(self):
      self.check_double_backward(
          cuda.to_gpu(self.x),
          cuda.to_gpu(self.gy),
          cuda.to_gpu(self.ggx),
          "never",
      )
  
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 16 for calling the TestSpatialPyramidPooling2D obj's underlying member method code with example usage: obj.test_double_backward_gpu_no_cudnn() without return types