code: def test_consistency_with_gpu(self):
      x_cpu, y_cpu = self.apply_backward(
          self.x, self.rois, self.roi_indices, self.gy
      )
      x_gpu, y_gpu = self.apply_backward(
          cuda.to_gpu(self.x),
          cuda.to_gpu(self.rois),
          cuda.to_gpu(self.roi_indices),
          cuda.to_gpu(self.gy),
      )
      testing.assert_allclose(y_cpu.data, y_gpu.data)
      testing.assert_allclose(x_cpu.grad, x_gpu.grad)
  
imports: import chainer
  from chainer.backends import cuda
  import chainer.functions
  from chainer import gradient_check
  from chainer import testing
  from chainer.testing import attr
  from chainer.testing import condition
  import numpy
  import unittest
  from chainercv import functions
label_desc: Use image node_id 9 for calling the TestPSROIMaxPooling2D obj's underlying member method code with example usage: obj.test_consistency_with_gpu() without return types