private function filterUri(string $passedUri): string
    {
        //sanitize url
        $url = \filter_var($passedUri, FILTER_SANITIZE_URL);

        //check for rewrite mode
        $url = \str_replace($this->rewriteModeOffRouter, '', $url);

        //remove basepath
        $url = \substr($url, \strlen($this->basePath));

        //remove doubled slash
        $url = \str_replace('//', '/', $url);

        return (\substr($url, 0, 1) === '/') ? $url : '/'.$url;
    }