public function ping($uri) {
        $parsed_url = parse_url($uri);
        if (!$parsed_url || !is_array($parsed_url)) {
            return false;
        }
        
        $http = new \GuzzleHttp\Client(array('base_uri' => $parsed_url['host']));
        $res = $http->get($parsed_url['path'] . '?' . $parsed_url['query']);
        if ( 200 !== $res->getStatusCode()) {
            return false;
        }
        $content = $res->getBody();
        return true;
    }