Aerys\CommandClient::writer PHP Method

    private function writer(string $watcherId, $socket)
    {
        $bytes = @fwrite($socket, $this->buf);
        if ($bytes == 0) {
            if (!is_resource($socket) || @feof($socket)) {
                \Amp\cancel($this->writeWatcher);
                $this->sock = $this->writeWatcher = null;
                $this->establish();
            }
            return;
        }
        if ($bytes === \strlen($this->buf)) {
            \Amp\cancel($watcherId);
            $this->writeWatcher = null;
        }
        $this->written += $bytes;
        foreach ($this->promisors as $end => $deferred) {
            if ($end > $this->written) {
                break;
            }
            $deferred->succeed();
            unset($this->promisors[$end]);
        }
    }