code: private static boolean isValidCarrierNode(final boolean sslEnabled, final NodeInfo nodeInfo) {
          if (sslEnabled && nodeInfo.sslServices().containsKey(ServiceType.BINARY)) {
              return true;
          } else if (nodeInfo.services().containsKey(ServiceType.BINARY)) {
              return true;
          }
          return false;
      }
docs: Helper method to detect if the given node can actually perform carrier refresh.
  
  @param sslEnabled true if ssl enabled, false otherwise.
  @param nodeInfo the node info for the given node.
  @return true if it is a valid carrier node, false otherwise.