code: def load_tests(loader, tests, ignore):
      # pylint: disable=unused-argument
      tests.addTests(
          doctest.DocTestSuite(towhee.datacollection.data_collection)
      )
      return tests
  
file_path: towhee/tests/unittests/datacollection/test_data_collection.py
imports: import doctest
  import unittest
  import towhee.datacollection.data_collection
  from towhee.datacollection import DataCollection
  from towhee import pipe
label_desc: Use image node_id 1 for calling a global function with example usage: load_tests(loader, tests, ignore) and returns: tests