return i
		}
	}
	return -1
}

func sortCallbacks(cs []*callback) (fns []func(*DB), err error) {
	var (
		names, sorted []string
		sortCallback  func(*callback) error
	)
	sort.SliceStable(cs, func(i, j int) bool {
		if cs[j].before == "*" && cs[i].before != "*" {
			return true
		}
		if cs[j].after == "*" && cs[i].after != "*" {
			return true
		}
		return false
	})

		// two delete markers on top of any object. To avoid this situation,
		// we will sort deletions to execute existing deletion first,
		// then add only one delete marker if requested
		sort.SliceStable(fivs.Versions, func(i, j int) bool {
			return !fivs.Versions[i].Deleted
		})
		if idx := slices.IndexFunc(fivs.Versions, func(fi FileInfo) bool {
			return fi.Deleted
		}); idx > -1 {