public function ack($deliveryTag, array $options = [])
    {
        $multiple = array_key_exists('multiple', $options) ? (int)$options['multiple'] : null;

        $outputFrame = Basic\BasicAckFrame::create($deliveryTag, $multiple);
        $outputFrame->frameChannelId = $this->id;
        $this->connection->command($outputFrame);
    }