public static NotificationCompat.Builder newBuilder(@Nullable final Context context, final NotificationChannels channel) {
        return new NotificationCompat.Builder(context == null ? CgeoApplication.getInstance() : context, channel.name())
                .setSmallIcon(R.drawable.cgeo_notification);
    }
A fresh not yet used notification id can be gathered via {@link cgeo.geocaching.settings.Settings#getUniqueNotificationId}
main/src/main/java/cgeo/geocaching/ui/notifications/Notifications.java