docs: @Override
      public List<MetricFamilySamples> collect() {
  
          final GaugeMetricFamily stats = new GaugeMetricFamily(
                  name,
                  "Rate Limiter Stats",
                  asList("name", "param"));
  
          for (RateLimiter rateLimiter : rateLimitersSupplier.get()) {
  
              final RateLimiter.Metrics metrics = rateLimiter.getMetrics();
  
              stats.addMetric(
                      asList(rateLimiter.getName(), "available_permissions"),
                      metrics.getAvailablePermissions());
  
              stats.addMetric(
                      asList(rateLimiter.getName(), "waiting_threads"),
                      metrics.getNumberOfWaitingThreads());
          }
  
          return singletonList(stats);
      }