code: def maybe_download_tesst_image(file_name):
      """Download the given TestImages file if not in the directory
  
      file_name - name of file to fetch
  
      Image will be downloaded if not present to CP_EXAMPLEIMAGES directory.
      """
      local_path = os.path.join(testimages_directory(), file_name)
      if not os.path.exists(local_path):
          url = testimages_url() + "/" + file_name
          try:
              URLopener().retrieve(url, local_path)
          except IOError as e:
              # This raises the "expected failure" exception.
              def bad_url(e=e):
                  raise e
  
              unittest.expectedFailure(bad_url)()
      return local_path
  
file_path: CellProfiler/tests/core/modules/__init__.py
imports: import os
  import tempfile
  import logging
  import functools
  import hashlib
  import numpy
  import unittest
  from urllib.request import URLopener
  import skimage.io
  import cellprofiler_core.utilities.legacy
label_desc: Use image node_id 9 for calling a global function with example usage: maybe_download_tesst_image(file_name) and returns: local_path