public static function autoload($class)
    {
        $_class = strtolower($class);
        $file = self::$SMARTY_SYSPLUGINS_DIR . $_class . '.php';
        if (strpos($_class, 'smarty_internal_') === 0) {
            if (strpos($_class, 'smarty_internal_compile_') === 0) {
                if (is_file($file)) {
                    require $file;
                }
                return;
            }
            @include $file;
            return;
        }
        if (preg_match('/^(smarty_(((template_(source|config|cache|compiled|resource_base))|((cached|compiled)?resource)|(variable|security)))|(smarty(bc)?)$)/',
                       $_class, $match)) {
            if (!empty($match[3])) {
                @include $file;
                return;
            } elseif (!empty($match[9]) && isset(self::$rootClasses[$_class])) {
                $file = self::$rootClasses[$_class];
                require $file;
                return;
            }
        }
        if (0 !== strpos($_class, 'smarty')) {
            return;
        }
        if (is_file($file)) {
            require $file;
            return;
        }
        return;
    }