docs: def _optimize_with_progs(format_module, filename, image_format):
      """
      Use the correct optimizing functions in sequence.
  
      And report back statistics.
      """
      filesize_in = os.stat(filename).st_size
      report_stats = None
  
      for func in format_module.PROGRAMS:
          if not getattr(Settings, func.__name__):
              continue
          report_stats = _optimize_image_external(
              filename, func, image_format, format_module.OUT_EXT)
          filename = report_stats.final_filename
          if format_module.BEST_ONLY:
              break
  
      if report_stats is not None:
          report_stats.bytes_in = filesize_in
      else:
          report_stats = stats.skip(image_format, filename)
  
      return report_stats