code: public static synchronized void shutdown() {
  		if (BACKGROUND_SERVICE != null) {
  			try {
  				BACKGROUND_SERVICE.stop();
  			} catch (Throwable t) {
  				LOGGER.error("Exception stopping Stackify Metrics API service", t);
  			}
  			
  			INITIALIZED.compareAndSet(true, false);
  		}
  	}
docs: Shut down the background thread that is processing metrics