code: def test_call_gpu(self):
      self.link.to_gpu()
      self.check_call()
  
file_path: chainercv/tests/links_tests/model_tests/resnet_tests/test_resnet.py
imports: import unittest
  import numpy
  from chainer.testing import attr
  from chainer import Variable
  from chainercv.links import ResNet101
  from chainercv.links import ResNet152
  from chainercv.links import ResNet50
  from chainercv.utils import testing
label_desc: Use image node_id 4 for calling the TestResNetCall obj's underlying member method code with example usage: obj.test_call_gpu() without return types