: new Node("groupby-" + sid, null, nmgr);
: new Node(sid, null, nmgr);
    public Node getGroupbySubnode(String sid, boolean create) {        loadNodes();        if (subnodes == null) {            subnodes = new ExternalizableVector();        }        NodeHandle ghandle = new NodeHandle(new SyntheticKey(getKey(), sid));        if (subnodes.contains(ghandle) || create) {            try {                DbMapping groupbyMapping = dbmap.getGroupbyMapping();                boolean relational = groupbyMapping.getSubnodeMapping().isRelational();                if (relational || create) {                    Node node = relational ? new Node(this, sid, nmgr, null)                                           : new Node("groupby-" + sid, null, nmgr);                    // set "groupname" property to value of groupby field                    node.setString("groupname", sid);                    if (relational) {                        node.setDbMapping(groupbyMapping);                    } else {                        setNode(sid, node);                        subnodes.add(node.getHandle());                    }                    node.setPrototype(groupbyMapping.getTypeName());                    nmgr.evictKey(node.getKey());                    return node;                }            } catch (Exception noluck) {                nmgr.logEvent("Error creating group-by node for " + sid + ": " + noluck);                noluck.printStackTrace();            }        }        return null;    }