docs: private void validateRestServiceConfiguration() {
          boolean isRestEnabled = voldemortConfig.isRestServiceEnabled();
          boolean isRestPortDefined = (identityNode.getRestPort() != -1) ? true : false;
          if(isRestEnabled != isRestPortDefined) {
              if(isRestEnabled) {
                  String errorMessage = "Rest Service is enabled without defining \"rest-port\" in cluster.xml .  "
                                        + this.identityNode.getStateString();
                  logger.error(errorMessage);
                  throw new VoldemortApplicationException(errorMessage);
              } else {
                  logger.warn("\"rest-port\" is defined in cluster.xml but Rest service is not enabled.");
              }
          }
      }