code: def setUp(self):
      self.img = np.random.randint(0, 255, size=(3, 32, 48))
      self.bbox = np.random.uniform(size=(self.n_bbox, 4))
      if self.label is not None:
          self.label = np.array(self.label, dtype=int)
      if self.score is not None:
          self.score = np.array(self.score)
      if not hasattr(self, "instance_colors"):
          self.instance_colors = None
  
file_path: chainercv/tests/visualizations_tests/test_vis_bbox.py
imports: import unittest
  import numpy
  from chainer import testing
  from chainercv.utils import generate_random_bbox
  from chainercv.visualizations import vis_bbox
label_desc: Use image node_id 1 for calling the TestVisBboxInvalidInputs obj's underlying member method code with example usage: obj.setUp() without return types