protected function unregisterJob(string $jobName, string $workerId) : bool
    {
        if (!isset($this->workerJobCapabilities[$jobName])) {
            return true;
        }
        if (($key = array_search($workerId, $this->workerJobCapabilities[$jobName])) !== false) {
            unset($this->workerJobCapabilities[$jobName][$key]);
        }
        if (empty($this->workerJobCapabilities[$jobName])) {
            unset($this->workerJobCapabilities[$jobName]);
        }
        return true;
    }