code: def test_backward_gpu(self):
      with chainer.using_config("use_cudnn", self.use_cudnn):
          self.check_backward(
              cuda.to_gpu(self.theta),
              self.output_shape,
              cuda.to_gpu(self.grads),
          )
  
file_path: chainer/tests/chainer_tests/functions_tests/array_tests/test_spatial_transformer_grid.py
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
label_desc: Use image node_id 7 for calling the TestSpatialTransformerGrid obj's underlying member method code with example usage: obj.test_backward_gpu() without return types