code: def setUp(self):
      self.n_anchor_base = 6
      self.feat_stride = 4
      self.n_fg_class = 3
      self.n_roi = 24
      self.n_bbox = 3
      self.link = FasterRCNNTrainChain(
          DummyFasterRCNN(
              n_anchor_base=self.n_anchor_base,
              feat_stride=self.feat_stride,
              n_fg_class=self.n_fg_class,
              n_roi=self.n_roi,
              min_size=600,
              max_size=800,
          )
      )
  
      self.bboxes = chainer.Variable(
          generate_random_bbox(self.n_bbox, (600, 800), 16, 350)[
              np.newaxis
          ]
      )
      _labels = np.random.randint(
          0, self.n_fg_class, size=(1, self.n_bbox)
      ).astype(np.int32)
      self.labels = chainer.Variable(_labels)
      self.imgs = chainer.Variable(_random_array((1, 3, 600, 800)))
      self.scales = chainer.Variable(np.array([1.0]))
  
file_path: chainercv/tests/links_tests/model_tests/faster_rcnn_tests/test_faster_rcnn_train_chain.py
imports: import numpy
  import unittest
  import chainer
  from chainer import testing
  from chainer.testing import attr
  from chainercv.links.model.faster_rcnn import FasterRCNNTrainChain
  from chainercv.utils import generate_random_bbox
  from tests.links_tests.model_tests.faster_rcnn_tests.dummy_faster_rcnn import DummyFasterRCNN
label_desc: Use image node_id 1 for calling the TestFasterRCNNTrainChain obj's underlying member method code with example usage: obj.setUp() without return types