If a sub-transaction was started and not committed or rolled back by the time the SubTransaction object is about to be disposed, the destructor will roll back the sub-transaction automatically, thus all changes made to the document during the sub-transaction will be discarded. It is not recommended to rely on this default behavior though. Instead, it is advised to always call either Commit or RollBack explicitly before the sub-transaction object gets disposed. Please note that unless invoked explicitly the actual destruction of an object in managed code might not happen until the object is collected by the garbage collector.