private void open(List<InetSocketAddress> transportAddresses, Map<String, String> userConfig) {

    final List<TransportAddress> transportNodes = new ArrayList<>(transportAddresses.size());

    for (InetSocketAddress address : transportAddresses) {

      transportNodes.add(new InetSocketTransportAddress(address));

    }



    Settings settings = Settings.settingsBuilder().put(userConfig).build();



    final TransportClient transportClient = TransportClient.builder().settings(settings).build();

    for (TransportAddress transport : transportNodes) {

      transportClient.addTransportAddress(transport);

    }



    final List<DiscoveryNode> nodes = ImmutableList.copyOf(transportClient.connectedNodes());

    if (nodes.isEmpty()) {

      throw new RuntimeException("Cannot connect to any elasticsearch nodes");

    }



    client = transportClient;

  }