private String address() {
        var addr = new StringBuilder();
        if (labels.size() == 1) {
            addr.append("'");
            addr.append(labels.get(0));
            addr.append("'");
        } else {
            addr.append("{");
            for (int idx = 0; idx < labels.size(); idx++) {
                if (idx > 0) {
                    addr.append(", ");
                }
                addr.append(meta.mappedDims().get(idx));
                addr.append(":'");
                addr.append(labels.get(idx));
                addr.append("'");
            }
            addr.append("}");
        }
        return addr.toString();
    }
Helper to incrementally build addresses and insert values (expression nodes) into a map.
Only used as an internal component of the RankingExpression parser.
@author arnej
searchlib/src/main/java/com/yahoo/searchlib/rankingexpression/parser/CellMapHelper.java