code: public boolean addInterceptorBefore(CommandInterceptor toAdd,
                                         Class<? extends CommandInterceptor> beforeInterceptor) {
        return asyncInterceptorChain.addInterceptorBefore(toAdd, beforeInterceptor);
     }
docs: Adds a new interceptor in list after an interceptor of a given type.
  
  @return true if the interceptor was added; i.e. the afterInterceptor exists