code: def test_forward_gpu(self):
      self.check_forward(cuda.cupy)
  
file_path: chainer/tests/chainer_tests/link_hooks_tests/test_timer.py
imports: import re
  import unittest
  import numpy
  import six
  import chainer
  from chainer.backends import cuda
  from chainer import link_hooks
  from chainer import testing
  from chainer.testing import attr
label_desc: Use image node_id 4 for calling the TestTimerHook obj's underlying member method code with example usage: obj.test_forward_gpu() without return types