/**
  *
  * @param array $msgParams
  * @param SecurityToken $token
  * @param boolean $signOwner
  * @param boolean $signViewer
  */
 private function addOpenSocialParams(&$msgParams, SecurityToken $token, $signOwner, $signViewer)
 {
     if ($signOwner) {
         $owner = $token->getOwnerId();
         if ($owner != null) {
             $msgParams[SigningFetcher::$OPENSOCIAL_OWNERID] = $owner;
         }
     }
     if ($signViewer) {
         $viewer = $token->getViewerId();
         if ($viewer != null) {
             $msgParams[SigningFetcher::$OPENSOCIAL_VIEWERID] = $viewer;
         }
     }
     if ($signOwner || $signViewer) {
         $app = $token->getAppId();
         if ($app != null) {
             $msgParams[SigningFetcher::$OPENSOCIAL_APPID] = $app;
         }
         $url = $token->getAppUrl();
         if ($url != null) {
             $msgParams[SigningFetcher::$OPENSOCIAL_APPURL] = $url;
         }
         $moduleId = $token->getModuleId();
         if ($moduleId != null) {
             $msgParams[SigningFetcher::$OPENSOCIAL_INSTANCEID] = $moduleId;
         }
     }
 }