/**
  * Release the jobs that have been reserved for too long.
  *
  * @param  string  $queue
  * @return void
  */
 protected function releaseJobsThatHaveBeenReservedTooLong($queue)
 {
     $expired = Carbon::now()->subSeconds($this->expire)->getTimestamp();
     $reserved = $this->database->collection($this->table)->where('queue', $this->getQueue($queue))->where('reserved', 1)->where('reserved_at', '<=', $expired)->get();
     foreach ($reserved as $job) {
         $attempts = $job['attempts'] + 1;
         $this->releaseJob($job['_id'], $attempts);
     }
 }