code: public OperationFuture<Server> addPublicIp(Server serverRef, CreatePublicIpConfig publicIpConfig) {
          checkNotNull(serverRef, "Server reference must be not null");
          checkNotNull(publicIpConfig, CHECK_PUBLIC_IP_CONFIG);
          Link response = client.addPublicIp(idByRef(serverRef), publicIpConverter.createPublicIpRequest(publicIpConfig));
  
          return new OperationFuture<>(
              serverRef,
              response.getId(),
              queueClient
          );
      }
docs: Add public IP to server
  
  @param serverRef        server reference
  @param publicIpConfig publicIp config
  @return OperationFuture wrapper for ServerRef