Aerys\WatcherProcess::doStop PHP Method

    protected function doStop() : \Generator
    {
        if (!$this->stopPromisor) {
            $this->stopPromisor = new Deferred();
            foreach ($this->ipcClients as $ipcClient) {
                @\fwrite($ipcClient, "\n");
            }
        }
        (yield $this->stopPromisor === true ? new Success() : $this->stopPromisor->promise());
    }