code: def change_nick(self,new_nick):
          
          new_room_jid=JID(self.room_jid.node,self.room_jid.domain,new_nick)
          p=Presence(to_jid=new_room_jid)
          self.manager.stream.send(p)
docs: Send a nick change request to the room.
  
          :Parameters:
              - `new_nick`: the new nickname requested.
          :Types:
              - `new_nick`: `unicode`