func (l *Logger) HasListener(flag, listenerName string) bool {
	l.Lock()
	defer l.Unlock()

	if l.Listeners == nil {
		return false
	}
	workers, ok := l.Listeners[flag]
	if !ok {
		return false
	}
	_, ok = workers[listenerName]
	return ok
}
// HasListener returns if a specific listener is registered for a flag.
HasListener returns if a specific listener is registered for a flag.
// HasListener returns if a specific listener is registered for a flag .
func (l *Logger) HasListener(flag, listenerName string) bool {
	l.Lock()
	defer l.Unlock()
	if l.Listeners == nil {
		return false
	}
	workers, ok := l.Listeners[flag]
	if !ok {
		return false
	}
	_, ok = workers[listenerName]
	return ok
}
func ( l * Logger ) HasListener ( flag , listenerName string ) bool { l . Lock ( ) defer l . Unlock ( ) if l . Listeners == nil { return false } workers , ok := l . Listeners [ flag ] if ! ok { return false } _ , ok = workers [ listenerName ] return ok }
HasListener returns if a specific listener is registered for a flag.
HasListener returns if a specific listener is registered for a flag .