code: def test_split_dataset_invalid_position(self):
      original = [1, 2, 3, 4, 5]
      with self.assertRaises(ValueError):
          datasets.split_dataset(original, -1)
      with self.assertRaises(ValueError):
          datasets.split_dataset(original, 6)
  
imports: import unittest
  from chainer import datasets
  from chainer import testing
label_desc: Use image node_id 4 for calling the TestSplitDataset obj's underlying member method code with example usage: obj.test_split_dataset_invalid_position() without return types