default Node getNode(String nodeID) {
        return getNode( new Node.UniqueIdentifier( getUniqueIdentifier(), nodeID));
    }
Returns the {@link Node} that matches the specified node ID or {@code null} if
none was found.

@param nodeID the ID that uniquely identifies the node in the pubsub service.
@return the Node that matches the specified node ID or {@code null} if none was found.
xmppserver/src/main/java/org/jivesoftware/openfire/pubsub/PubSubService.java