scala.util.control.Exception Problem

Can anyone tell me some knowledge and usage of ‘scala.util.control.Exception._’?
Such as
val rollbackIfException = handling(classOf[Throwable]) by { //???
t =>
{
tx.rollback()
throw t
}
}
rollbackIfException[A] { //??
val session = new Session(conn, Some(tx))
val result: A = execution(session)
tx.commit()
result
}