code: def test_predict_gpu(self):
      self.link.to_gpu()
      assert_is_detection_link(self.link, self.n_class - 1)
  
imports: import numpy
  import unittest
  import chainer
  from chainer import testing
  from chainer.testing import attr
  from chainercv.utils import assert_is_detection_link
  from tests.links_tests.model_tests.faster_rcnn_tests.dummy_faster_rcnn import DummyFasterRCNN
label_desc: Use image node_id 6 for calling the TestFasterRCNN obj's underlying member method code with example usage: obj.test_predict_gpu() without return types