Documentation Request Summary:

We've introduced three new shell helpers: startTransaction(), commitTransaction(), and abortTransaction(). All three require that a Session has been started and must be called on it.

startTransaction can take optional transaction options (readConcern and writeConcern). These can only be set at the beginning of a transaction and will be used for all subsequent statements in a transaction.

calling commitTransaction allows you to see your changes outside of the transaction.

calling abortTransaction terminates the transaction and none of the changes will be saved.

Please let me know if anything is unclear! I committed a test with the server ticket so that should make things easier to understand.