public function handleSignal($signal)
    {
        switch ($signal) {
        case SIGINT:
            $this->log(
                'Received SIGINT, shutting down.' . PHP_EOL,
                Net_Notifier_Logger::VERBOSITY_ALL
            );
            $this->moribund = true;
            break;

        case SIGTERM:
            $this->log(
                'Received SIGTERM, shutting down.' . PHP_EOL,
                Net_Notifier_Logger::VERBOSITY_ALL
            );
            $this->moribund = true;
            break;
        }
    }