/**
  * Select unassigned slots for a given queue name
  *
  * @param queueName name of queue
  * @return unassigned slot object if found
  * @throws AndesException
  */
 @Override
 public Slot selectUnAssignedSlot(String queueName) throws AndesException {
   try {
     return wrappedAndesContextStoreInstance.selectUnAssignedSlot(queueName);
   } catch (AndesStoreUnavailableException exception) {
     notifyFailures(exception);
     throw exception;
   }
 }