code: def test_vanilla(self):
      # Test that ImageOpener does add '.mgz' as gzipped file type
      with InTemporaryDirectory():
          with ImageOpener("test.gz", "w") as fobj:
              assert hasattr(fobj.fobj, "compress")
          with ImageOpener("test.mgz", "w") as fobj:
              assert hasattr(fobj.fobj, "compress")
  
imports: import contextlib
  import hashlib
  import os
  import time
  import unittest
  from gzip import GzipFile
  from io import BytesIO, UnsupportedOperation
  from unittest import mock
  import pytest
  from packaging.version import Version
  from ..deprecator import ExpiredDeprecationError
  from ..openers import HAVE_INDEXED_GZIP, BZ2File, DeterministicGzipFile, ImageOpener, Opener
  from ..optpkg import optional_package
  from ..tmpdirs import InTemporaryDirectory
label_desc: Use image node_id 1 for calling the TestImageOpener obj's underlying member method code with example usage: obj.test_vanilla() without return types