code: private void addManagementMetrics(Collection<Metric<?>> result) {
          try {
              // Add JVM up time in ms
              result.add(new Metric<>("uptime", ManagementFactory.getRuntimeMXBean().getUptime()));
              result.add(new Metric<>("systemload.average", ManagementFactory.getOperatingSystemMXBean().getSystemLoadAverage()));
              this.addHeapMetrics(result);
              addNonHeapMetrics(result);
              this.addThreadMetrics(result);
              this.addClassLoadingMetrics(result);
              this.addGarbageCollectionMetrics(result);
          } catch (NoClassDefFoundError ex) {
              // Expected on Google App Engine
          }
      }
docs: Add metrics from ManagementFactory if possible. Note that ManagementFactory is not available on Google App Engine.
  
  @param result the result