@Override
    public void messageReceived(JID roomJID, JID user, String nickname, Message message) {
        // Not used.
    }
Removes and returns all data that was maintained for cluster nodes other than the local node. It is assumed that
this method is used in reaction to the local cluster node having left the cluster.

@return All data that this instance maintained for all cluster nodes except the local one.
xmppserver/src/main/java/org/jivesoftware/openfire/muc/spi/OccupantManager.java