void setPresenceBasedDelivery(boolean presenceBasedDelivery) {
        this.presenceBasedDelivery = presenceBasedDelivery;
    }
Sets whether subscribers will be notified when items are removed from the node.

@param notifyRetract true if subscribers will be notified when items are removed from
       the node.
xmppserver/src/main/java/org/jivesoftware/openfire/pubsub/Node.java