@Override
    @Nonnull
    public Set<Node.UniqueIdentifier> findDirectlySubscribedNodes(@Nonnull JID address) {
        flushPendingNodes();
        return delegate.findDirectlySubscribedNodes(address);
    }
Cache for recently accessed published items.
xmppserver/src/main/java/org/jivesoftware/openfire/pubsub/CachingPubsubPersistenceProvider.java