code: def maybe_download(url, work_directory):
      
      filename = url.split("/")[-1]
      filepath = os.path.join(work_directory, filename)
      if not os.path.exists(filepath):
          logger.info("Downloading to {}...".format(filepath))
          download(url, work_directory)
      return filepath
docs: Download the data from Marlin's website, unless it's already here.