@Override
        public void accept(Metric m) {
            String description = m.getDescription();
            MetricId alias = MetricId.empty;
            boolean isForwarded = false;

            for (ConfiguredMetric metric : getMetricDefinitions(consumer)) {
                if (metric.id().equals(m.getName())) {
                    alias = metric.outputname();
                    isForwarded = true;
                    if (description.isEmpty()) {
                        description = metric.description();
                    }
                }
            }

            String message = "OFF";
            StringBuilder buffer = bufferOff;
            if (isForwarded) {
                buffer = bufferOn;
                message = "ON";
            }
            buffer.append(m.getName()).append('=').append(message);
            if (!description.isEmpty()) {
                buffer.append(";description=").append(description);
            }
            if (!alias.id.isEmpty()) {
                buffer.append(";output-name=").append(alias);
            }
            buffer.append(',');
        }
Returns a string representation of metrics for the given services;
a space separated list of key=value.
metrics-proxy/src/main/java/ai/vespa/metricsproxy/core/VespaMetrics.java