/**
  * singleton pattern
  *
  * @return PlentySoapDaemon
  */
 public static function getInstance()
 {
     if (!isset(self::$instance) || !self::$instance instanceof PlentySoapDaemon) {
         self::$instance = new PlentySoapDaemon();
     }
     return self::$instance;
 }
 function plentySoapDaemonSigHandler($signo)
 {
     switch ($signo) {
         case SIGTERM:
         case SIGINT:
             PlentySoapDaemon::getInstance()->stopDaemon();
             break;
     }
 }