docs: public void registerMetrics() {
          if (metricsAreRegistered) {
              return;
          }
          getMetricRegistry().register("jvm.attribute", new JvmAttributeGaugeSet());
          getMetricRegistry().register("jvm.buffers", new BufferPoolMetricSet(ManagementFactory
                                                                                 .getPlatformMBeanServer()));
          getMetricRegistry().register("jvm.classloader", new ClassLoadingGaugeSet());
          getMetricRegistry().register("jvm.filedescriptor", new FileDescriptorRatioGauge());
          getMetricRegistry().register("jvm.gc", new GarbageCollectorMetricSet());
          getMetricRegistry().register("jvm.memory", new MemoryUsageGaugeSet());
          getMetricRegistry().register("jvm.threads", new ThreadStatesGaugeSet());
  
          JmxReporter.forRegistry(metricRegistry).build().start();
          metricsAreRegistered = true;
      }