private void callback(final CounterWithCallback.Callback callback) {
    labelledCallbackData
        .values()
        .forEach(
            callbackData ->
                callback.call(
                    callbackData.valueSupplier().getAsDouble(), callbackData.labelValues()));
  }
A Prometheus supplied counter collector. A supplied counter collector is one which actual value
is kept outside the metric system, for example in an external library or to calculate the value
only on demand when a metric scrape occurs.
metrics/core/src/main/java/org/hyperledger/besu/metrics/prometheus/PrometheusSuppliedCounter.java