code: def test_ungzip(self):
      with testing_utils.tempdir() as tmpdir:
          import gzip
  
          fname = os.path.join(tmpdir, "test.txt.gz")
          with gzip.GzipFile(fname, mode="w") as f:
              f.write("This is a test\n".encode("utf-8"))
          build_data.ungzip(tmpdir, "test.txt.gz")
          out_fn = os.path.join(tmpdir, "test.txt")
          assert os.path.exists(out_fn)
          assert not os.path.exists(fname)
          with open(out_fn) as f:
              assert f.read() == "This is a test\n"
  
imports: import os
  import pytest
  from parlai.core import build_data
  import unittest
  import unittest.mock
  import requests
  import parlai.utils.testing
  import multiprocessing
  from parlai.utils.io import PathManager
  from parlai.core.params import ParlaiParser
label_desc: Use image node_id 1 for calling the TestUnzip obj's underlying member method code with example usage: obj.test_ungzip() without return types