for (final Map<String, String> labelMap : labelTypeItems) {
                    if (!first1) {
                        buf.append(',');
                    } else {
                        first1 = false;
                    }
                    buf.append("{\"label\":");
                    buf.append(escapeJson(labelMap.get(Constants.ITEM_LABEL)));
                    buf.append(", \"value\":");