code: def setUp(self):
      self.ds = SimpleDataset([1, 2, 3, 4, 5])
  
file_path: chainer/tests/chainer_tests/dataset_tests/test_dataset_mixin.py
imports: import unittest
  import numpy
  from chainer import dataset
  from chainer import testing
label_desc: Use image node_id 1 for calling the TestDatasetMixin obj's underlying member method code with example usage: obj.setUp() without return types