[Twisted-Python] xmlrpc and deferred result doubts

Hi All I have a doubt about how to factor the an xmlrpc server code. Basicly what happens is: def xmlrpc_runCmd(self, hostname, command): # I call a method that returns a deferred and because of that I # don't have anything to return to the xmlrpc client. runComm = conn.runCommand(hostname, command) # the line below doesn't make much sense because the output needs to # return to the xmlrpc client runComm.addCallback(self.printOutput) return ???? # return what?!?!?!? What should I do? How should I factor the code? Thanks Gustavo