public void Authorize(string authKey, string username, string password, Action <OAuthResponse> success = null, Action <OAuthResponse> error = null) { OAuth.FlowPasswordCredentials( username, password, (OAuthResponse response) => { Authorization = new KeyValuePair <string, string>(authKey, response.access_token); if (success != null) { success(response); } }, (OAuthResponse response) => { if (error != null) { error(response); } } ); }