code: def _check_anchors(self):
      anchors = self.link.anchors(((32, 32), (16, 16), (8, 8)))
  
      self.assertEqual(len(anchors), 3)
      for l in range(3):
          self.assertIsInstance(anchors[l], self.link.xp.ndarray)
          self.assertEqual(
              anchors[l].shape, ((32 * 32 >> 2 * l) * 3, 4)
          )
  
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 5 for calling the TestRPN obj's underlying member method code with example usage: obj._check_anchors() without return types