code: def _print_duration(self):
          '''Print the elapsed download time.'''
          duration = int(time.time() - self._start_time)
          self._print(datetime.timedelta(seconds=duration)f _print_duration(self):
          '''Print the elapsed download time.'''
          duration = int(time.time() - self._start_time)
          self._print(datetime.timedelta(seconds=duration))
docs: Print the elapsed download time.