/**
  * Return the approximate number of messages in the queue
  *
  * @param  Zend_Queue $queue
  * @return integer
  * @throws Zend_Queue_Exception (not supported)
  */
 public function count(Zend_Queue $queue = null)
 {
     if ($queue !== null) {
         return $queue->count();
     }
     return false;
 }