code: def get_room_jid(self,nick=None):
          
          if nick is None:
              return self.room_jid
          return JID(self.room_jid.node,self.room_jid.domain,nick)
docs: Get own room JID or a room JID for given `nick`.
  
          :Parameters:
              - `nick`: a nick for which the room JID is requested.
          :Types:
              - `nick`: `unicode`
  
          :return: the room JID.
          :returntype: `JID`