// for any status *not* in the given list.
func StatusIsNot(statuses ...int) StacktracePred {
	statusesNoTrace := map[int]bool{}
	for _, s := range statuses {
		statusesNoTrace[s] = true
	}
	return func(status int) bool {
		_, ok := statusesNoTrace[status]
		return !ok
	}
}

// Addf adds additional data to be logged with this request.