/**
* Construct an instance of YouTube service.
*
* @param string $key The YouTube API key
* @param Client|null $client The Guzzle HTTP client
*/
public function __construct($key = null, Client $client = null)
{
parent::__construct($key ?: config('koel.youtube.key'), null, 'https://www.googleapis.com/youtube/v3', $client ?: new Client());
}