'L{AdoptedStreamServerEndpoint.listen} sets the file description given
to it to non-blocking.'

def test_descriptionNonBlocking(self):

    reactor = MemoryReactor()
    endpoint = self._createStubbedAdoptedEndpoint(reactor, 13, AF_INET)
    events = []
    def setNonBlocking(fileno):
        events.append(('setNonBlocking', fileno))
    endpoint._setNonBlocking = setNonBlocking
    d = endpoint.listen(object())
    def listened(ignored):
        self.assertEqual([('setNonBlocking', 13)], events)
    d.addCallback(listened)
    return d
