'When a port starts, a message including a description of the associated
factory is logged.'

def test_startedListeningLogMessage(self):

    loggedMessages = self.observe()
    reactor = self.buildReactor()
    @implementer(ILoggingContext)
    class SomeFactory(ServerFactory, ):
        def logPrefix(self):
            return 'Crazy    Factory'
    factory = SomeFactory()
    p = self.getListeningPort(reactor, factory)
    expectedMessage = self.getExpectedStartListeningLogMessage(p, 'Crazy    Factory')
    self.assertEqual((expectedMessage,), loggedMessages[0]['message'])
