(mongodb >=1.5.0)
MongoDB\Driver\Session::commitTransaction — Commits a transaction
Saves the changes made by the operations in the multi-document transaction and ends the transaction. Until the commit, none of the data changes made from within the transaction are visible outside the transaction.
У цієї функції немає параметрів.
Не повертає значень.
"errorLabels" element, and this array contains a
   "TransientTransactionError" or
   "UnknownTransactionCommitResult" value, it is safe to re-try
   the whole transaction. In newer versions of the
   extension,
   MongoDB\Driver\Exception\RuntimeException::hasErrorLabel()
   should be used to test for this situation instead.