code: public function save()
      {
          try
          {
              $connection = new Connection($this->buildConnectionOptions());
              $connection->open();
  
              $msg = new AMQPMessage($this->message, array('content_type' => $this->content_type, 'delivery_mode' => 2));
              $connection->channel->basic_publish($msg, $this->exchange, $this->queue_name);
  
              $connection->close();
          }
          catch (Exception $e)
          {
              $connection->close();
              throw new Exception($e);
          }
      }
docs: Save the current message instance into de queue server
  
  @return void