code: public Meter addMeter(final String name) {
      final Meter curr = this.registry.meter(name);
      this.registry.register(name + "-gauge", (Gauge<Double>) curr::getOneMinuteRate);
      return curr;
    }
docs: A {@link Meter} measures the rate of events over time (e.g., “requests per second”). Here we
  track 1-minute moving averages.