/**
* @param bool|null $data
*
* @throws QlessException If the heartbeat fails
* @return int timestamp of the heartbeat
*/
public function heartbeat($data = null)
{
// (now, jid, worker, data)
if (is_array($data)) {
$data = json_encode($data, JSON_UNESCAPED_SLASHES);
}
return $this->expires = $this->client->heartbeat($this->jid, $this->worker_name, $data);
}
