Importing nested classes/static methods/static fields with commonly-used names can make code harder to read, because it may not be clear from the context exactly which type is being referred to. Qualifying the name with that of the containing class can make the code clearer. Here we recommend using qualified class: GitTransactionHandle.

Return value of methods returning Future must be checked. Ignoring returned Futures suppresses exceptions thrown from the code that completes the Future.

Streams that encapsulate a closeable resource should be closed using try-with-resources

Date has a bad API that leads to bugs; prefer java.time.Instant or LocalDate.