Twisted Trial: как протестировать MultiService с клиентом Reactor был нечист

Я унаследовал Twisted MultiService, к которому пытаюсь добавить тесты, но что бы я ни делал, я получаю ошибку DirtyReactorAggregateError. Служба подключается к серверу с именем twisted.application.internet.TCPClient. Я думаю, что ошибка связана с тем, что TCPClient не отключается, но я не уверен, как я должен его отключить. Как правильно протестировать Twisted Service с клиентом?

Вот тестовый пример:

from labrad.node import *
from twisted.trial import unittest
import os
from socket import gethostname

class NodeTestCase(unittest.TestCase):

    def setUp(self):
        import labrad
        name = os.environ.get('LABRADNODE', gethostname()) + '_test'
        self.node = Node(name,
            labrad.constants.MANAGER_HOST,
            labrad.constants.MANAGER_PORT)
        self.node.startService()
        #self.addCleanup(self.node.stopService)

    def test_nothing(self):
        self.assertEqual(3, 3)

    def tearDown(self):
        return self.node.stopService()

Вот сам сервис Node:

class Node(MultiService):
    """Parent Service that keeps the node running.

    If the manager is stopped or we lose the network connection,
    this service attempts to restart it so that we will come
    back online when the manager is back up.
    """
    reconnectDelay = 10

    def __init__(self, name, host, port):
        MultiService.__init__(self)
        self.name = name
        self.host = host
        self.port = port

    def startService(self):
        MultiService.startService(self)
        self.startConnection()

    def startConnection(self):
        """Attempt to start the node and connect to LabRAD."""
        print 'Connecting to %s:%d...' % (self.host, self.port)
        self.node = NodeServer(self.name, self.host, self.port)
        self.node.onStartup().addErrback(self._error)
        self.node.onShutdown().addCallbacks(self._disconnected, self._error)
        self.cxn = TCPClient(self.host, self.port, self.node)
        self.addService(self.cxn)

    def stopService(self):
        if hasattr(self, 'cxn'):
            d = defer.maybeDeferred(self.cxn.stopService)
            self.removeService(self.cxn)
            del self.cxn
            return defer.gatherResults([MultiService.stopService(self), d])
        else:
            return MultiService.stopService(self)

    def _disconnected(self, data):
        print 'Node disconnected from manager.'
        return self._reconnect()

    def _error(self, failure):
        r = failure.trap(UserError)
        if r == UserError:
            print "UserError found!"
            return None
        print failure.getErrorMessage()
        return self._reconnect()

    def _reconnect(self):
        """Clean up from the last run and reconnect."""
        ## hack: manually clearing the dispatcher...
        dispatcher.connections.clear()
        dispatcher.senders.clear()
        dispatcher._boundMethods.clear()
        ## end hack
        if hasattr(self, 'cxn'):
            self.removeService(self.cxn)
            del self.cxn
        reactor.callLater(self.reconnectDelay, self.startConnection)
        print 'Will try to reconnect in %d seconds...' % self.reconnectDelay