public function appyAuthorization(RequestInterface $request, array $options = null)
    {
        // Only sign requests using "auth"="oauth"
        // IMPORTANT: you have to create special auth client (GuzzleHttp\Client) if you want to get all the request authorized
        if (!isset($options['auth']) || $options['auth'] != 'oauth') {
            return $request;
        }

        // get Access token for current request
        $accessToken = $this->getAccessToken();
        if (is_string($accessToken)) {
            return $request->withHeader('Authorization', 'Bearer ' . $accessToken);
        } else {
            throw new ClientError('Authentication error, invalid on no access token data returned.');
        }
    }