如何在android上获取oouth_timestamp，oauth_nonce，oauth_signature for Flickr OAuth

Question

对于Flickr OAuth身份验证，我正在验证已经获得OAuth令牌的用户。

OAuth mOauth = OAuth.newInstance(activity.getApplicationContext(),
                activity.getSupportFragmentManager(),
                new ClientParametersAuthentication(FlickrDemoConstants.FLICKR_API_KEY,
                        FlickrDemoConstants.FLICKR_API_SECRET),
                AUTHORIZATION_VERIFIER_SERVER_URL,
                TOKEN_SERVER_URL,
                REDIRECT_URL,
                Lists.<String>newArrayList(),
                TEMPORARY_TOKEN_REQUEST_URL);

Credential mCredential = mOauth.authorize10a(
                    userId).getResult();
            if(FlickrDemoConstants.DEBUG_ENABLE) {
                Log.i(TAG, "token: " + mCredential.getAccessToken());

但是我怎么做oauth_timestamp，oauth_nonce，oauth_signature？