/**
  * @param string $appName The application's name
  * @param string $appVersion The application's version
  * @param string $appUrl The application's URL
  */
 public static function setAppInfo($appName, $appVersion = null, $appUrl = null)
 {
     if (self::$appInfo === null) {
         self::$appInfo = array();
     }
     self::$appInfo['name'] = $appName;
     self::$appInfo['version'] = $appVersion;
     self::$appInfo['url'] = $appUrl;
 }