public function flagShutdown(string $message = null): void
    {
        $this->isShutdown = true;
        $this->shutdownMessage = (null === $message ? 'Daemon flagged for shutdown' : $message);
    }
public function flagShutdown(string $message = null): void
    {
        $this->isShutdown = true;
        $this->shutdownMessage = (null === $message ? 'Daemon flagged for shutdown' : $message);
    }
public function flagShutdown ( string $ message = null ) : void { $ this -> isShutdown = true ; $ this -> shutdownMessage = ( null === $ message ? 'Daemon flagged for shutdown' : $ message ) ; }
Flags the daemon for shutting down.

@param string $message Optional shutdown message
Flags the daemon for shutting down .