void aggregate(Metric metric) {
            Map<DimensionId, String> mergedDimensions = new LinkedHashMap<>();
            mergedDimensions.putAll(metric.getDimensions());
            mergedDimensions.putAll(serviceDimensions);
            AggregationKey aggregationKey = new AggregationKey(mergedDimensions, metric.getConsumers());
            aggregated.computeIfAbsent(aggregationKey, key -> new ArrayList<>()).add(metric);
        }
Returns the metrics to output for the given service, with updated timestamp
In order to include a metric, it must exist in the given map of metric to consumers.
Each returned metric will contain a collection of consumers that it should be routed to.
metrics-proxy/src/main/java/ai/vespa/metricsproxy/core/VespaMetrics.java