old_contents: import numpy as np
  import unittest
  
  from chainer import testing
  
  from chainercv.utils import assert_is_image
  
  
  @testing.parameterize(
      {
          'img': np.random.randint(0, 256, size=(3, 48, 64)),
          'color': True, 'check_range': True, 'valid': True},
      {
          'img': np.random.randint(0, 256, size=(1, 48, 64)),
          'color': True, 'check_range': True, 'valid': False},
      {
          'img': np.random.randint(0, 256, size=(4, 48, 64)),
          'color': True, 'check_range': True, 'valid': False},
      {
          'img': np.ones((3, 48, 64)) * 256,
          'color': True, 'check_range': True, 'valid': False},
      {
          'img': np.ones((3, 48, 64)) * -1,
          'color': True, 'check_range': True, 'valid': False},
      {
          'img': np.ones((3, 48, 64)) * 256,
          'color': True, 'check_range': False, 'valid': True},
  
      {
          'img': np.random.randint(0, 256, size=(1, 48, 64)),
          'color': False, 'check_range': True, 'valid': True},
      {
          'img': np.random.randint(0, 256, size=(3, 48, 64)),
          'color': False, 'check_range': True, 'valid': False},
      {
          'img': np.ones((1, 48, 64)) * 256,
          'color': False, 'check_range': True, 'valid': False},
      {
          'img': np.ones((1, 48, 64)) * -1,
          'color': False, 'check_range': True, 'valid': False},
      {
          'img': np.ones((1, 48, 64)) * 256,
          'color': False, 'check_range': False, 'valid': True},
  )
  class TestAssertIsImage(unittest.TestCase):
  
      def test_assert_is_image(self):
          if self.valid:
              assert_is_image(self.img, self.color, self.check_range)
          else:
              with self.assertRaises(AssertionError):
                  assert_is_image(self.img, self.color, self.check_range)
  
  
  testing.run_module(__name__, __file__)
  
new_contents: import numpy as np
  import unittest
  
  from chainer import testing
  
  from chainercv.utils import assert_is_image
  
  
  @testing.parameterize(
      {
          'img': np.random.randint(0, 256, size=(3, 48, 64)),
          'color': True, 'check_range': True, 'valid': True},
      {
          'img': np.random.randint(0, 256, size=(1, 48, 64)),
          'color': True, 'check_range': True, 'valid': False},
      {
          'img': np.random.randint(0, 256, size=(4, 48, 64)),
          'color': True, 'check_range': True, 'valid': False},
      {
          'img': np.ones((3, 48, 64)) * 256,
          'color': True, 'check_range': True, 'valid': False},
      {
          'img': np.ones((3, 48, 64)) * -1,
          'color': True, 'check_range': True, 'valid': False},
      {
          'img': np.ones((3, 48, 64)) * 256,
          'color': True, 'check_range': False, 'valid': True},
  
      {
          'img': np.random.randint(0, 256, size=(1, 48, 64)),
          'color': False, 'check_range': True, 'valid': True},
      {
          'img': np.random.randint(0, 256, size=(3, 48, 64)),
          'color': False, 'check_range': True, 'valid': False},
      {
          'img': np.ones((1, 48, 64)) * 256,
          'color': False, 'check_range': True, 'valid': False},
      {
          'img': np.ones((1, 48, 64)) * -1,
          'color': False, 'check_range': True, 'valid': False},
      {
          'img': np.ones((1, 48, 64)) * 256,
          'color': False, 'check_range': False, 'valid': True},
  
      {
          'img': (((0, 1), (2, 3)), ((4, 5), (6, 7)), ((8, 9), (10, 11))),
          'color': True, 'check_range': True, 'valid': False},
  )
  class TestAssertIsImage(unittest.TestCase):
  
      def test_assert_is_image(self):
          if self.valid:
              assert_is_image(self.img, self.color, self.check_range)
          else:
              with self.assertRaises(AssertionError):
                  assert_is_image(self.img, self.color, self.check_range)
  
  
  testing.run_module(__name__, __file__)
  
subject: add tuple case