def test_modePreservation(self):
        """
        Check rotated files have same permissions as original.
        """
        open(self.path, "w").close()
        os.chmod(self.path, 0o707)
        mode = os.stat(self.path)[stat.ST_MODE]
        log = logfile.LogFile(self.name, self.dir)
        self.addCleanup(log.close)
        log.write("abc")
        log.rotate()
        self.assertEqual(mode, os.stat(self.path)[stat.ST_MODE])

        Check rotated files have same permissions as original.
        
stackoverflow/venv/lib/python3.6/site-packages/twisted/test/test_logfile.py