presto-thrift/src/main/java/io/prestosql/plugin/thrift/ThriftIndexPageSource.java/ThriftIndexPageSource/openClient
class ThriftIndexPageSource:    private PrestoThriftService openClient(PrestoThriftSplit split)
    {
        if (split.getHosts().isEmpty()) {
            return client.get(thriftHeaders);
        }
        String hosts = split.getHosts().stream()
                .map(host -> host.toHostAddress().toString())
                .collect(joining(","));
        return client.get(Optional.of(hosts), thriftHeaders);
    }