code: def test_anchors_gpu(self):
      self.link.to_gpu()
      self._check_anchors()
  
imports: from __future__ import division
  import numpy
  import unittest
  import chainer
  from chainer import testing
  from chainer.testing import attr
  from chainercv.links.model.fpn import RPN
  from chainercv.links.model.fpn import rpn_loss
label_desc: Use image node_id 7 for calling the TestRPN obj's underlying member method code with example usage: obj.test_anchors_gpu() without return types