@Override
    public void markedAsSeniorClusterMember() {
        // Do nothing
    }
When the users sessions cache is (potentially) inconsistent, it can be rebuilt from routeOwnersByClusterNode and
routingTable.
This method relies on the routeOwnersByClusterNode and routingTable being stable and reflecting the actual
reality. So run this restore method <em>after or at the end of</em> cleanup on a cluster leave.
xmppserver/src/main/java/org/jivesoftware/openfire/spi/RoutingTableImpl.java