code: def operation_download(uploader, sources):
      
      sources, destinations = destination_from_source(sources, False)
      print('sources', sources)
      print('destinations', destinations)
      if len(destinations) == len(sources):
          if uploader.prepare():
              for filename, dst in zip(sources, destinations):
                  uploader.read_file(filename, dst)
      else:
          raise Exception('You must specify a destination filename for each file you want to download.')
      log.info('All done!')
docs: The download operation