code: @Deprecated
      public <T> T onFallbackSuccess(HystrixInvokable<T> commandInstance, T fallbackResponse) {
          // pass-thru by default
          return fallbackResponse;
      }
docs: DEPRECATED: Change usages of this to {@link #onFallbackEmit} if you want to write a hook that handles each emitted fallback value
  or to {@link #onFallbackSuccess} if you want to write a hook that handles success of the fallback method
  
  Invoked after successful execution of {@link HystrixCommand#getFallback()} with response value.
  
  @param commandInstance
  The executing HystrixCommand instance.
  @param fallbackResponse
  from {@link HystrixCommand#getFallback()}
  @return T response object that can be modified, decorated, replaced or just returned as a pass-thru.
  
  @since 1.2