code: def test_call_cpu(self):
      self.check_call()
  
imports: import numpy
  import unittest
  import chainer
  from chainer import testing
  from chainer.testing import attr
  from chainercv.links.model.light_head_rcnn import LightHeadRCNN
  from chainercv.utils import assert_is_detection_link
  from chainercv.utils import generate_random_bbox
label_desc: Use image node_id 3 for calling the TestLightHeadRCNN obj's underlying member method code with example usage: obj.test_call_cpu() without return types