code: protected void addClassLoadingMetrics(Collection<Metric<?>> result) {
          ClassLoadingMXBean classLoadingMxBean = ManagementFactory.getClassLoadingMXBean();
          result.add(new Metric<>("classes", (long) classLoadingMxBean.getLoadedClassCount()));
          result.add(new Metric<>("classes.loaded", classLoadingMxBean.getTotalLoadedClassCount()));
          result.add(new Metric<>("classes.unloaded", classLoadingMxBean.getUnloadedClassCount()));
      }
docs: Add class loading metrics.
  
  @param result the result