code: func (l *Log) Fatalln(args ...interface{}) {
  	opts := getLoggerOpts(l.module, api.CRITICAL)
  	if l.loadCustomLogger() {
  		l.customLogger.Fatalln(args...)
  		return
  	}
  	l.logln(opts, api.CRITICAL, args...)
  	l.deflogger.Fatalln(args...)
  }
docs: // Fatalln is CRITICAL log ln followed by a call to os.Exit(1).