How do I set delivery_mode on message using php extension AMQP with RabbitMQ? -

i've set whole infrastructure meaning i've configure php amqp extension http://www.php.net/manual/en/book.amqp.php. i've set durable exchange , queue. know should publish message delivery_mode = 2 (or equivalent in php) according http://www.rabbitmq.com/tutorial-two-python.html. don't know if can , if don't know how.

$message = new amqpmessage(serialize($object), array('content_type' => 'text/plain', 'delivery_mode' => 2)); 

this using http://code.google.com/p/php-amqplib/, guess native extension has similar syntax.