This is a package that contains an implementation of an abstract synchronisation mechanism - synchronisation group. The main idea is to have an ability to run independent tasks in separate goroutines which way return errors. A user can wait until all goroutines finish running and collect all occurred errors.
The design is similar to errgroup (https://godoc.org/golang.org/x/sync/errgroup), but it does not cancel the context of the goroutines if any of them returns an error.
See more on godoc site