code: def test_random_flip_vertical(self):
      img = np.random.uniform(size=(3, 24, 24))
  
      out = flip(img, y_flip=True, x_flip=False)
  
      expected = img
      expected = expected[:, ::-1, :]
      np.testing.assert_equal(out, expected)
  
file_path: chainercv/tests/transforms_tests/image_tests/test_flip_transform.py
imports: import unittest
  import numpy
  from chainer import testing
  from chainercv.transforms import flip
label_desc: Use image node_id 2 for calling the TestRandomFlip obj's underlying member method code with example usage: obj.test_random_flip_vertical() without return types