public function getInfo($only = null)
    {
        if (empty($only)) {
            $uri = 'asterisk/info';
        } else {
            $uri = "asterisk/info?only=$only";
        }
        $response = $this->client->getEndpoint()->get($uri);

        return new AsteriskInfo(\GuzzleHttp\json_decode($response->getBody()));
    }