docs: def fetch_url(url, dest, parent_to_remove_before_fetch):
      """Helper function to fetch a file from a URL."""
      logger.debug('Downloading file {} from {}', dest, url)
      try:
          shutil.rmtree(parent_to_remove_before_fetch)
      except FileNotFoundError:
          pass
      os.makedirs(parent_to_remove_before_fetch)
      # TODO(itamar): Better downloading (multi-process-multi-threaded?)
      # Consider offloading this to a "standalone app" invoked with Docker
      resp = requests.get(url, stream=True)
      with open(dest, 'wb') as fetch_file:
          for chunk in resp.iter_content(chunk_size=32 * 1024):
              fetch_file.write(chunk)