def addUser(self, user):
        self.roster[user.nick] = user
Implements (well enough for our purposes) DOM node import.
dataset/ETHPy150Open ralphm/wokkel/wokkel/muc.py/Room.addUser--crossover with--dataset/ETHPy150Open AppScale/appscale/AppServer/google/appengine/api/SOAPpy/wstools/Utility.py/DOM.importNode