final NodesHotThreadsResponse response =
                    esClient.admin().cluster().prepareNodesHotThreads().setIgnoreIdleThreads(ignoreIdleThreads).setInterval(interval)
                            .setThreads(threads).setTimeout(timeout).setType(type).execute().actionGet(timeout);
            append(buf, "cluster_name", () -> response.getClusterName().value()).append(',');

            return b.toString();
        }).collect(Collectors.joining(",")));
        buf.append("},");
        final Threads threads = jvmStats.getThreads();
        buf.append("\"threads\":{");
        append(buf, "count", () -> threads.getCount()).append(',');
        append(buf, "peak", () -> threads.getPeakCount());
        buf.append("},");