@Override
    public void loadSubscription( Node node, String subId )
    {
        // Affiliate change should already be stored in the node.
        log.debug( "Loading subscription {} for node: {} (NOP)", subId, node.getUniqueIdentifier() );
    }
Cache that holds all published items (mapped by node ID).
xmppserver/src/main/java/org/jivesoftware/openfire/pubsub/InMemoryPubSubPersistenceProvider.java