public static function modelAliasToClass($model) {
        $classes = self::getAllModels();

        foreach ($classes as $class) {
            if ($class->alias === $model || $class->class === self::ENTITIES_NAMESPACE.'_'.$model) {
                return $class->class;
            }
        }
        throw new Garp_Content_Exception('Invalid model alias specified: '.$model);
    }