code: def test_get_cross_validation_datasets(self):
      original = [1, 2, 3, 4, 5, 6]
      cv1, cv2, cv3 = datasets.get_cross_validation_datasets(
          original, 3
      )
  
      tr1, te1 = cv1
      self.assertEqual(len(tr1), 4)
      self.assertEqual(tr1[0], 1)
      self.assertEqual(tr1[1], 2)
      self.assertEqual(tr1[2], 3)
      self.assertEqual(tr1[3], 4)
      self.assertEqual(len(te1), 2)
      self.assertEqual(te1[0], 5)
      self.assertEqual(te1[1], 6)
  
      tr2, te2 = cv2
      self.assertEqual(len(tr2), 4)
      self.assertEqual(tr2[0], 5)
      self.assertEqual(tr2[1], 6)
      self.assertEqual(tr2[2], 1)
      self.assertEqual(tr2[3], 2)
      self.assertEqual(len(te2), 2)
      self.assertEqual(te2[0], 3)
      self.assertEqual(te2[1], 4)
  
      tr3, te3 = cv3
      self.assertEqual(len(tr3), 4)
      self.assertEqual(tr3[0], 3)
      self.assertEqual(tr3[1], 4)
      self.assertEqual(tr3[2], 5)
      self.assertEqual(tr3[3], 6)
      self.assertEqual(len(te3), 2)
      self.assertEqual(te3[0], 1)
      self.assertEqual(te3[1], 2)
  
imports: import unittest
  from chainer import datasets
  from chainer import testing
label_desc: Use image node_id 1 for calling the TestGetCrossValidationDatasets obj's underlying member method code with example usage: obj.test_get_cross_validation_datasets() without return types