/**
* Make signature for authorized request
*
* @return string
*/
public function getSignature()
{
$signString = sprintf("%s\n%s\n%s\n%d", $this->topic, $this->producerId, md5($this->message->getBody()), $this->time);
return base64_encode(hash_hmac('sha1', $signString, $this->getAuthorization()->getAccessSecret(), true));
}
