@Override
  public OperationTimer labels(final String... labels) {
    final DistributionDataPoint metric = ((Summary) collector).labelValues(labels);
    return () -> metric.startTimer()::observeDuration;
  }
An implementation of Besu timer backed by a Prometheus summary. The summary provides a total
count of durations and a sum of all observed durations, it calculates configurable quantiles over
a sliding time window.
metrics/core/src/main/java/org/hyperledger/besu/metrics/prometheus/PrometheusTimer.java