code: def check_prepare(self):
      x = _random_array(np, self.in_shape)
      out = self.link.prepare(x)
      self.assertIsInstance(out, np.ndarray)
      self.assertEqual(out.shape, self.expected_shape)
  
imports: import numpy
  import unittest
  import chainer
  from chainer import testing
  from chainer.testing import attr
  from chainercv.utils import assert_is_detection_link
  from tests.links_tests.model_tests.faster_rcnn_tests.dummy_faster_rcnn import DummyFasterRCNN
label_desc: Use image node_id 2 for calling the TestFasterRCNNPrepare obj's underlying member method code with example usage: obj.check_prepare() without return types