code: def setUpClass(cls):
      super(Wiki40bTest, cls).setUpClass()
      wiki40b._DATA_DIRECTORY = _EXAMPLE_DIR
  
imports: import os
  from tensorflow_datasets import testing
  from tensorflow_datasets.text import wiki40b
label_desc: Use image node_id 1 for calling the Wiki40bTest obj's underlying member method code with example usage: obj.setUpClass(cls) without return types