code: def determine_bytes_per_chunk(self, size):
          
          workers = self.settings.config.download_workers
          if not workers or workers == 'None':
              workers = 1
          bytes_per_chunk = int(math.ceil(size / float(workers)))
          if bytes_per_chunk < self.bytes_per_chunk:
              bytes_per_chunk = self.bytes_per_chunk
          return bytes_per_chunk
docs: Calculate the size of chunk a worker should download.
          The last worker may download less than this depending on file size.
          :return: int: byte size for a worker