private function getOauthParams($nonce)
    {
        $params = [
            'oauth_nonce'            => $nonce,
            'oauth_timestamp'        => time(),
        ];

        if (isset($this->oauth_token)) {
            $params['oauth_token'] = $this->oauth_token;
        }

        $params = $this->oauthConfig->toArray($params);

        return $params;
    }