public function getQueues()
 {
     if (null === $this->_queues) {
         $this->_queues = parent::getQueues();
     }
     return $this->_queues;
 }
 /**
  * List all queues.
  *
  * @param  array $options
  * @return array Queue IDs
  */
 public function listQueues($options = null)
 {
     try {
         return $this->_sqs->getQueues();
     } catch (Zend_Service_Amazon_Exception $e) {
         throw new Zend_Cloud_QueueService_Exception('Error on listing queues: ' . $e->getMessage(), $e->getCode(), $e);
     }
 }