code: def __on_download_progress_update(self, blocknum, blocksize, totalsize):
          
          if not self.__show_download_progress:
              return
  
          readsofar = blocknum * blocksize
          if totalsize > 0:
              s = "\r%s / %s" % (size(readsofar), size(totalsize))
              sys.stdout.write(s)
              if readsofar >= totalsize:  # near the end
                  sys.stderr.write("\r")
          else:  # total size is unknown
              sys.stdout.write("\rread %s" % (size(readsofar)))
docs: Prints some download progress information
          :param blocknum:
          :param blocksize:
          :param totalsize:
          :return: