public Builder applyOutputNames(Map<MetricId, List<MetricId>> outputNamesById) {
            Map<MetricId, Number> newMetrics = new LinkedHashMap<>();
            outputNamesById.forEach((id, outputNames) -> {
                if (metrics.containsKey(id))
                    outputNames.forEach(outputName -> newMetrics.put(outputName, metrics.get(id)));
            });
            metrics = newMetrics;
            return this;
        }
Represents a packet of metrics (with meta information) that belong together because they:
<ul>
    <li>share both the same dimensions and consumers, AND</li>
    <li>represent the same source, e.g. a vespa service or the system hardware.</li>
</ul>

@author gjoranv
metrics-proxy/src/main/java/ai/vespa/metricsproxy/metric/model/MetricsPacket.java