public NodeAffiliate addOutcast(JID jid) {
        NodeAffiliate nodeAffiliate = addAffiliation(jid, NodeAffiliate.Affiliation.outcast);
        // Delete existing subscriptions
        removeSubscriptions(jid);
        return nodeAffiliate;
    }
Sets that the specified entity is an outcast of the node. Outcast entities are not
able to publish or subscribe to the node. Existing subscriptions will be deleted.

@param jid the JID of the user that is no longer able to publish or subscribe to the node.
@return the newly created or modified affiliation to the node.
xmppserver/src/main/java/org/jivesoftware/openfire/pubsub/Node.java