def test_eventAsTextTimestampOnly(self):
        """
        If includeTimestamp is specified as the only option no system or
        traceback are printed.
        """
        if tzset is None:
            raise SkipTest(
                "Platform cannot change timezone; unable to verify offsets."
            )

        addTZCleanup(self)
        setTZ("UTC+00")

        try:
            raise CapturedError("This is a fake error")
        except CapturedError:
            f = Failure()

        t = mktime((2013, 9, 24, 11, 40, 47, 1, 267, 1))
        event = {
            "log_format": u"ABCD",
            "log_system": u"fake_system",
            "log_time": t,
        }
        event["log_failure"] = f
        eventText = eventAsText(
            event,
            includeTimestamp=True,
            includeTraceback=False,
            includeSystem=False,
        )
        self.assertEqual(
            eventText,
            u"2013-09-24T11:40:47+0000 ABCD",
        )

        If includeTimestamp is specified as the only option no system or
        traceback are printed.
        
stackoverflow/venv/lib/python3.6/site-packages/twisted/logger/test/test_format.py