code: def setUp(self):
      faster_rcnn = FasterRCNNVGG16(
          n_fg_class=self.n_fg_class, pretrained_model=False
      )
      self.link = FasterRCNNTrainChain(faster_rcnn)
  
      self.n_bbox = 3
      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)
      _imgs = np.random.uniform(
          low=-122.5, high=122.5, size=(1, 3, 600, 800)
      ).astype(np.float32)
      self.imgs = chainer.Variable(_imgs)
      self.scale = chainer.Variable(np.array([1.0]))
  
imports: import numpy
  import unittest
  import chainer
  from chainer import testing
  from chainer.testing import attr
  from chainercv.links import FasterRCNNVGG16
  from chainercv.links.model.faster_rcnn import FasterRCNNTrainChain
  from chainercv.utils import generate_random_bbox
label_desc: Use image node_id 1 for calling the TestFasterRCNNVGG16Loss obj's underlying member method code with example usage: obj.setUp() without return types