class IFingerSetterService(Interface):

    def setUser(user, status):
        """Set the user's status to something"""

# Advantages of latest version

class MemoryFingerService(service.Service):

    implements([IFingerService, IFingerSetterService])

    def __init__(self, **kwargs):
        self.users = kwargs

    def getUser(self, user):
        return defer.succeed(self.users.get(user, "No such user"))

    def getUsers(self):
        return defer.succeed(self.users.keys())

    def setUser(self, user, status):
        self.users[user] = status


f = MemoryFingerService(moshez='Happy and well')
serviceCollection = service.IServiceCollection(application)
internet.TCPServer(1079, IFingerSetterFactory(f), interface='127.0.0.1'
                   ).setServiceParent(serviceCollection)