@Override
 public void removeMemberRoleListener(ChatRoomMemberRoleListener listener) {
   memberRoleListeners.remove(listener);
 }
 @Override
 public void removeMemberPresenceListener(ChatRoomMemberPresenceListener listener) {
   synchronized (memberListeners) {
     memberListeners.remove(listener);
   }
 }
 @Override
 public void removelocalUserRoleListener(ChatRoomLocalUserRoleListener listener) {
   localUserRoleListeners.remove(listener);
 }
 /**
  * Removes a white board frame.
  *
  * @param frame the frame to remove
  */
 public void removeWhiteboardWindow(WhiteboardFrame frame) {
   synchronized (wbFrames) {
     wbFrames.remove(frame);
   }
 }