code: public static void reset() {
          getInstance().notifier.set(null);
          getInstance().concurrencyStrategy.set(null);
          getInstance().metricsPublisher.set(null);
          getInstance().propertiesFactory.set(null);
          getInstance().commandExecutionHook.set(null);
          HystrixMetricsPublisherFactory.reset();
      }
docs: Reset all of the HystrixPlugins to null.  You may invoke this directly, or it also gets invoked via <code>Hystrix.reset()</code>