def plugin(self,owner,request=1):
        """ Register presence and subscription trackers in the owner's dispatcher.
            Also request roster from server if the 'request' argument is set.
            Used internally."""
        self._owner.RegisterHandler('iq',self.RosterIqHandler,'result',NS_ROSTER)
        self._owner.RegisterHandler('iq',self.RosterIqHandler,'set',NS_ROSTER)
        self._owner.RegisterHandler('presence',self.PresenceHandler)
        if request: self.Request()
 Register presence and subscription trackers in the owner's dispatcher.
            Also request roster from server if the 'request' argument is set.
            Used internally.
chrome-cordova/gcmServer/xmpp/roster.py