code: def test_http_error(self):
      error = downloader.requests.exceptions.HTTPError(
          "Problem serving file."
      )
      mock.patch.object(
          downloader.requests.Session, "get", side_effect=error
      ).start()
      promise = self.downloader.download(self.url, self.tmp_dir)
      with self.assertRaises(downloader.requests.exceptions.HTTPError):
          promise.get()
  
imports: import hashlib
  import io
  import os
  import tempfile
  from typing import Optional
  from unittest import mock
  import pytest
  import tensorflow
  from tensorflow_datasets import testing
  from tensorflow_datasets.core.download import downloader
  from tensorflow_datasets.core.download import resource
  from tensorflow_datasets.core.download import util
label_desc: Use image node_id 5 for calling the DownloaderTest obj's underlying member method code with example usage: obj.test_http_error() without return types