@Override
    public void readExternal(ObjectInput in) throws IOException, ClassNotFoundException {
        byte[] bytes = ExternalizableUtil.getInstance().readByteArray(in);
        // Retrieve the NodeID but try to use the singleton instance
        if (XMPPServer.getInstance().getNodeID().equals(bytes)) {
            nodeID = XMPPServer.getInstance().getNodeID();
        }
        else {
            nodeID = NodeID.getInstance(bytes);
        }
        available = ExternalizableUtil.getInstance().readBoolean(in);
    }
Internal object used by RoutingTableImpl to keep track of the node that own a ClientSession
and whether the session is available or not.

@author Gaston Dombiak
xmppserver/src/main/java/org/jivesoftware/openfire/spi/ClientRoute.java