public function requestValue($name)
    {
        $response = $this->client->request('GET', sprintf('/session/%s/%s', $this->sessionId, $name));
        $content = json_decode($response->getContent(), true);

        if (!isset($content['value'])) {
            throw new LibraryException('Malformed response: expected a key "value" in JSON response: '.$response->getContent());
        }

        return $content['value'];
    }