I want to truncate the log until "Transaction ID" (not DLSN). How can I do ?

Now , I want to truncate the log until "Transaction ID" (not DLSN),
I find that :

```java
DLSN truncateDLSN = ...;
Future<DLSN> truncateFuture = writer.truncate(truncateDLSN);
// wait for truncation result
Await.result(truncateFuture);
```

http://distributedlog.incubator.apache.org/docs/latest/user_guide/api/core.html#asynclogwriter

So,ow can I do ?