Logs progress information about ongoing module download.

    Args:
      bytes_downloaded: Number of bytes downloaded.

def _log_progress(self, bytes_downloaded):
    """Logs progress information about ongoing module download.

    Args:
      bytes_downloaded: Number of bytes downloaded.
    """
    self._total_bytes_downloaded += bytes_downloaded
    now = time.time()
    if (self._interactive_mode() or
        now - self._last_progress_msg_print_time > 15):
      # Print progress message every 15 secs or if interactive progress
      # tracking is enabled.
      self._print_download_progress_msg(
          "Downloading %s: %s" % (self._url,
                                  tf_utils.bytes_to_readable_str(
                                      self._total_bytes_downloaded, True)))
      self._last_progress_msg_print_time = now