/**
  * Pop the next job off of the queue.
  *
  * @param  string $queue
  *
  * @return \Illuminate\Queue\Jobs\Job|null
  */
 public function pop($queue = null)
 {
     $queue = $this->getQueue($queue);
     $options = new ReceiveMessageOptions();
     $options->setPeekLock();
     $job = $this->azure->receiveQueueMessage($queue, $options);
     if (!is_null($job)) {
         return new AzureJob($this->container, $this->azure, $job, $queue);
     }
 }