Map<String, MiddlewareHandler> middlewareMap = new HashMap<>();
        // Middleware Handlers plugged into the handler chain.
        MiddlewareHandler[] middlewareHandlers = SingletonServiceFactory.getBeans(MiddlewareHandler.class);
        // construct middleware handler map.
        if(middlewareHandlers != null) {
            for (int i = middlewareHandlers.length - 1; i >= 0; i--) {
                logger.info("Plugin: " + middlewareHandlers[i].getClass().getName());
                if(middlewareHandlers[i].isEnabled()) {
                    middlewareHandlers[i].register();
                    middlewareMap.put(middlewareHandlers[i].getClass().getName(), middlewareHandlers[i]);
                }
            }
        }
        // now we need to construct the chains based on middleware.yml, if this config file doesn't exist
        // we need to build the default chain out of service.yml for backward compatibility.



        gracefulShutdownHandler = new GracefulShutdownHandler(handler);