public function send($destination, $msg, array $header = [], $sync = null)
    {
        if (!$msg instanceof Frame) {
            return $this->send($destination, new Frame('SEND', $header, $msg), [], $sync);
        }

        $msg->addHeaders($header);
        $msg['destination'] = $destination;
        return $this->sendFrame($msg, $sync);
    }