public function accessToken($url, $body = '')
{
$parsed_url = parse_url($url);
$path = $parsed_url['path'];
$access = $path;
if (isset($parsed_url['query'])) {
$access .= "?" . $parsed_url['query'];
}
$access .= "\n";
if ($body) {
$access .= $body;
}
return self::sign($this->sk, $this->ak, $access);
}