anchor.diff:  * `rootCauseExceptionTypeHeaderName` (`"Root-Cause-Exception-Type"`)
   * `rootCauseExceptionMessageHeaderName` (`"Root-Cause-Exception-Message"`)
   
  -For more information on circuit breakers and the gateway see the <<hystrix, Hystrix GatewayFilter Factory section>> or <<spring-cloud-circuitbreaker-filter-factory, Spring Cloud CircuitBreaker Factory section>>.
  +For more information on circuit breakers and the gateway see the <<spring-cloud-circuitbreaker-filter-factory, Spring Cloud CircuitBreaker Factory section>>.
   
   === The `MapRequestHeader` `GatewayFilter` Factory
   
  
positive.code: [[fallback-headers]]
  === The `FallbackHeaders` `GatewayFilter` Factory
  
  The `FallbackHeaders` factory lets you add Hystrix or Spring Cloud CircuitBreaker execution exception details in the headers of a request forwarded to a `fallbackUri` in an external application, as in the following scenario:
  
  .application.yml
  ====
  
negative.code: spring.cloud.gateway.discovery.locator.predicates[0].args[pattern]: "'/'+serviceId+'/**'"
  spring.cloud.gateway.discovery.locator.predicates[1].name: Host
  spring.cloud.gateway.discovery.locator.predicates[1].args[pattern]: "'**.foo.com'"
  spring.cloud.gateway.discovery.locator.filters[0].name: CircuitBreaker
  spring.cloud.gateway.discovery.locator.filters[0].args[name]: serviceId
  spring.cloud.gateway.discovery.locator.filters[1].name: RewritePath
  spring.cloud.gateway.discovery.locator.filters[1].args[regexp]: "'/' + serviceId + '/(?<remaining>.*)'"
  