code: def test_full_backward_gpu(self):
      with testing.assert_warns(DeprecationWarning):
          self.link.to_gpu()
      self.check_backward(
          cuda.to_gpu(self.gc),
          cuda.to_gpu(self.gh),
          *[cuda.to_gpu(v) for v in self.inputs],
      )
  
imports: import unittest
  import numpy
  import chainer
  from chainer import backend
  from chainer.backends import cuda
  from chainer import gradient_check
  from chainer import links
  from chainer import testing
  from chainer.testing import attr
  from chainer.testing import condition
label_desc: Use image node_id 18 for calling the TestTreeLSTM obj's underlying member method code with example usage: obj.test_full_backward_gpu() without return types