code: function findByID($id, $queue = null)
      {
          $queue = $this->_normalizeQueueName($queue);
  
          if (! isset($this->queues[$queue]) )
              return null;
  
          if (! isset($this->queues[$queue][(string)$id]) )
              return null;
  
  
          $item = $this->queues[$queue][(string)$id];
  
          $payload = $item['payload'];
          return $payload;
      }
docs: Find Queued Payload By Given ID
  
  @param string $id
  @param string $queue
  
  @return iPayloadQueued|null
  @throws exIOError