code: public Resourcepart getNickname() {
          final EntityFullJid myRoomJid = this.myRoomJid;
          if (myRoomJid == null) {
              return null;
          }
          return myRoomJid.getResourcepart();
      }
docs: Returns the nickname that was used to join the room, or <tt>null</tt> if not
  currently joined.
  
  @return the nickname currently being used.