code: public synchronized boolean hasAccess(String queueName, QueueOperation oper,
                                  UserGroupInformation ugi) {
      return hasAccess(queueName, null, oper, ugi);
    }
docs: Return true if the given {@link QueueManager.QueueOperation} can be
  performed by the specified user on the given queue.
  
  An operation is allowed if all users are provided access for this
  operation, or if either the user or any of the groups specified is
  provided access.
  
  @param queueName Queue on which the operation needs to be performed.
  @param oper The operation to perform
  @param ugi The user and groups who wish to perform the operation.
  
  @return true if the operation is allowed, false otherwise.