logger.go
func (l *logger) Facilities() (enabled, disabled []string) {
	l.mut.Lock()
	for facility, isEnabled := range l.debug {
		if isEnabled {
			enabled = append(enabled, facility)
		} else {
			disabled = append(disabled, facility)
		}
	}
	l.mut.Unlock()
	return
}
func (l *logger) Facilities() (enabled, disabled []string) {
	l.mut.Lock()
	for facility, isEnabled := range l.debug {
		if isEnabled {
			enabled = append(enabled, facility)
		} else {
			disabled = append(disabled, facility)
		}
	}
	l.mut.Unlock()
	return
}
// Facilities returns the currently known set of facilities, both those for
// which debug is enabled and those for which it is disabled.