@PostConstruct
	public void init() {
		// blockRequestHandlerOptional has low priority
		blockRequestHandlerOptional.ifPresent(GatewayCallbackManager::setBlockHandler);
		initAppType();
		initFallback();
	}
@author <a href="mailto:fangjian0423@gmail.com">Jim</a>
spring-cloud-alibaba-starters/spring-cloud-alibaba-sentinel-gateway/src/main/java/com/alibaba/cloud/sentinel/gateway/scg/SentinelSCGAutoConfiguration.java