presto-kudu/src/main/java/io/prestosql/plugin/kudu/KuduPageSink.java/KuduPageSink/appendPage
class KuduPageSink:    @Override
    public CompletableFuture<?> appendPage(Page page)
    {
        for (int position = 0; position < page.getPositionCount(); position++) {
            Upsert upsert = table.newUpsert();
            PartialRow row = upsert.getRow();
            int start = 0;
            if (generateUUID) {
                String id = format("%s-%08x", uuid, nextSubId++);
                row.addString(0, id);
                start = 1;
            }

            for (int channel = 0; channel < page.getChannelCount(); channel++) {
                appendColumn(row, page, position, channel, channel + start);
            }

            try {
                session.apply(upsert);
            }
            catch (KuduException e) {
                throw new RuntimeException(e);
            }
        }
        return NOT_BLOCKED;
    }