def METHOD_NAME(self):
    """Test that we can open a gzip file correctly."""
    filename = os.path.join(self.testdir, self.filename + ".bz2")
    with BZ2File(filename, mode="wb") as bz2file:
        bz2file.write(self.file_content)
    store = factory.getobject(filename)
    assert isinstance(store, self.expected_instance)