code: def _check_decode(self):
      locs = [
          chainer.Variable(
              _random_array(self.link.xp, (2, 32 * 32 * 3, 4))
          ),
          chainer.Variable(
              _random_array(self.link.xp, (2, 16 * 16 * 3, 4))
          ),
          chainer.Variable(
              _random_array(self.link.xp, (2, 8 * 8 * 3, 4))
          ),
      ]
      confs = [
          chainer.Variable(
              _random_array(self.link.xp, (2, 32 * 32 * 3))
          ),
          chainer.Variable(
              _random_array(self.link.xp, (2, 16 * 16 * 3))
          ),
          chainer.Variable(_random_array(self.link.xp, (2, 8 * 8 * 3))),
      ]
      anchors = self.link.anchors(((32, 32), (16, 16), (8, 8)))
  
      rois, roi_indices = self.link.decode(
          locs, confs, anchors, (2, 3, 64, 64)
      )
  
      self.assertIsInstance(rois, self.link.xp.ndarray)
      self.assertIsInstance(roi_indices, self.link.xp.ndarray)
      self.assertEqual(rois.shape[0], roi_indices.shape[0])
      self.assertEqual(rois.shape[1:], (4,))
      self.assertEqual(roi_indices.shape[1:], ())
  
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 8 for calling the TestRPN obj's underlying member method code with example usage: obj._check_decode() without return types