public function activate()
    {
        if (!$this->active) {
            $this->client->sendFrame(
                $this->getProtocol()->getSubscribeFrame(
                    $this->subscription->getDestination(),
                    $this->subscription->getSubscriptionId(),
                    $this->subscription->getAck(),
                    $this->subscription->getSelector(),
                    true
                )->addHeaders(
                    $this->options->getOptions()
                )
            );
            $this->active = true;
        }
    }