public function stopBroadcast($broadcastId)
    {
        // validate arguments
        Validators::validateBroadcastId($broadcastId);

        // make API call
        $broadcastData = $this->client->stopBroadcast($broadcastId);
        return new Broadcast($broadcastData, array(
            'client' => $this->client,
            'isStopped' => true
        ));
    }