'LogEntry.action_time is a timestamp of the date when the entry was
created. It shouldn\'t be updated on a subsequent save().'

def test_logentry_save(self):

    logentry = LogEntry.objects.get(content_type__model__iexact='article')
    action_time = logentry.action_time
    logentry.save()
    self.assertEqual(logentry.action_time, action_time)
