public void setServerNodeInfoProvider(String node, DiscoItemsProvider provider) {
        serverNodeProviders.put(node, provider);
    }
Sets the DiscoItemsProvider to use when a disco#items packet is sent to the server itself
and the specified node. For instance, if node matches "http://jabber.org/protocol/offline"
then a special DiscoItemsProvider should be use to return information about offline messages.

@param node the node that the provider will handle.
@param provider the DiscoItemsProvider that will handle disco#items packets sent with the
       specified node.
xmppserver/src/main/java/org/jivesoftware/openfire/disco/IQDiscoItemsHandler.java