code: public OperationFuture<Server> modifyPublicIp(Server server, String publicIp, ModifyPublicIpConfig config) {
          checkNotNull(config, "PublicIpConfig must be not null");
          checkNotNull(publicIp, "public ip must not be null");
  
          Link response = client.modifyPublicIp(idByRef(server),
              publicIp,
              publicIpConverter.createPublicIpRequest(config)
          );
  
          return new OperationFuture<>(
              server,
              response.getId(),
              queueClient
          );
      }
docs: Modify provided public IP on server
  @param server server reference
  @param publicIp public ip
  @param config publicIp config
  @return OperationFuture wrapper for ServerRef