Evernote\Client::getShardIdFromToken PHP Method

    protected function getShardIdFromToken($token)
    {
        $result = preg_match('/:?S=(s[0-9]+):?/', $token, $matches);
        if ($result === 1 && array_key_exists(1, $matches)) {
            return $matches[1];
        }
        return null;
    }