Support other protocols in CircuitBreaker Fallback URI

spring:
  application:
    name: gateway-server
  cloud:
    gateway:
      discovery:
        locator:
          enabled: true
          lowerCaseServiceId: true
      routes:
      - id: service-hi
        uri: lb://SERVICE-HI
        predicates:
        - Path=/demo/**
        filters:
        - name: Hystrix
          args:
            name: fetchIngredientss
            fallbackUri: forward:/hi
      - id: ingredients-fallback
        uri: http://localhost:8888
        predicates:
        - Path=/hi

上面的配置经断路器可以跳转到http://localhost:8888/hi，但是如果把 http://localhost:8888改成lb://SERVICE-HI就不能跳转到SERVICE-HI/hi这个地址了 为什么

The above configuration can jump to http://localhost:8888/hi via circuit breaker, but if you change http://localhost:8888 to lb://SERVICE-HI, you can't jump to SERVICE-HI/hi address. Why?

Reproduce the supplied Gateway configuration, comparing fallbackUri values of forward:/hi, http://localhost:8888, and lb://SERVICE-HI. Trace the CircuitBreaker fallback URI resolution and service lookup; done means the lb://SERVICE-HI fallback reaches SERVICE-HI/hi or the supported limitation is clearly documented.