code: def _check_call(self):
      x = _random_array(self.link.xp, (1, 3, 32, 32))
  
      mb_locs, mb_confs = self.link(x)
  
      self.assertIsInstance(mb_locs, chainer.Variable)
      self.assertIsInstance(mb_locs.array, self.link.xp.ndarray)
      self.assertEqual(mb_locs.shape, (1, self.n_bbox, 4))
      self.assertIsInstance(mb_confs, chainer.Variable)
      self.assertIsInstance(mb_confs.array, self.link.xp.ndarray)
      self.assertEqual(
          mb_confs.shape, (1, self.n_bbox, self.n_fg_class + 1)
      )
  
imports: import numpy
  import unittest
  import chainer
  from chainer import testing
  from chainer.testing import attr
  from chainercv.links.model.ssd import Multibox
  from chainercv.links.model.ssd import SSD
  from chainercv.utils import assert_is_detection_link
label_desc: Use image node_id 2 for calling the TestSSD obj's underlying member method code with example usage: obj._check_call() without return types