'A published old-style event should format as text in the same way as
the given C{textFromEventDict} callable would format it.'

def test_message(self):

    def textFromEventDict(event):
        return ''.join(reversed('    '.join(event['message'])))
    event = self.legacyEvent('Hello,', 'world!')
    text = textFromEventDict(event)
    publishToNewObserver(self.observer, event, textFromEventDict)
    self.assertEqual(formatEvent(self.events[0]), text)
