new_contents: import unittest
  
  import numpy as np
  
  from chainer import testing
  from chainercv.transforms import rotate_bbox
  from chainercv.utils import generate_random_bbox
  
  
  @testing.parameterize(*testing.product({
      'k': [0, 1, 2, 3]
  }))
  class TestRotateBbox(unittest.TestCase):
  
      def test_rotate_bbox(self):
          size = (32, 24)
          bbox = generate_random_bbox(10, size, 0, 24)
  
          out = rotate_bbox(bbox, self.k, size)
          if (4 - self.k) % 2 == 1:
              rotate_size = size[::-1]
          else:
              rotate_size = size
          out = rotate_bbox(out, 4 - self.k, rotate_size)
  
          np.testing.assert_equal(out, bbox)
  
  
  testing.run_module(__name__, __file__)
  
subject: add test_rotate_bbox.py