code: def test_download_gzip_file(self):
      fpath = cache(
          url="https://static.preferred.ai/cornac/tests/dummy.tar.gz",
          unzip=True,
          relative_path="dummy/gz.txt",
      )
      self.assertTrue(os.path.exists(fpath))
      with open(fpath, "r") as f:
          self.assertEqual("gz", f.read().strip())
  
file_path: cornac/tests/cornac/utils/test_download.py
imports: import os
  import unittest
  from cornac.utils.download import cache
label_desc: Use image node_id 3 for calling the TestDownload obj's underlying member method code with example usage: obj.test_download_gzip_file() without return types