code: def _check_decode(self):
      rois = [
          self.link.xp.array(((4, 1, 6, 3),), dtype=np.float32),
          self.link.xp.array(
              ((0, 1, 2, 3), (5, 4, 10, 6)), dtype=np.float32
          ),
          self.link.xp.array(((10, 4, 12, 10),), dtype=np.float32),
      ]
      roi_indices = [
          self.link.xp.array((0,), dtype=np.int32),
          self.link.xp.array((1, 0), dtype=np.int32),
          self.link.xp.array((1,), dtype=np.int32),
      ]
      locs = chainer.Variable(
          _random_array(self.link.xp, (4, self.n_class, 4))
      )
      confs = chainer.Variable(
          _random_array(self.link.xp, (4, self.n_class))
      )
  
      bboxes, labels, scores = self.link.decode(
          rois,
          roi_indices,
          locs,
          confs,
          (0.4, 0.2),
          ((100, 100), (200, 200)),
          0.5,
          0.1,
      )
  
      self.assertEqual(len(bboxes), 2)
      self.assertEqual(len(labels), 2)
      self.assertEqual(len(scores), 2)
      for n in range(2):
          self.assertIsInstance(bboxes[n], self.link.xp.ndarray)
          self.assertIsInstance(labels[n], self.link.xp.ndarray)
          self.assertIsInstance(scores[n], self.link.xp.ndarray)
  
          self.assertEqual(bboxes[n].shape[0], labels[n].shape[0])
          self.assertEqual(bboxes[n].shape[0], scores[n].shape[0])
          self.assertEqual(bboxes[n].shape[1:], (4,))
          self.assertEqual(labels[n].shape[1:], ())
          self.assertEqual(scores[n].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 bbox_head_loss_post
  from chainercv.links.model.fpn import bbox_head_loss_pre
  from chainercv.links.model.fpn import BboxHead
label_desc: Use image node_id 8 for calling the TestBboxHead obj's underlying member method code with example usage: obj._check_decode() without return types