从ActionMessage中删除消息

Question

如何从ActionMessage中删除特定的错误消息。例如，msgKey下面是"ABC"，msg.getKey()是"ABC"。现在两者都相同时我想从ActionMessage中删除密钥。我该怎么做？

Iterator it = warningMessages.get(ActionMessages.GLOBAL_MESSAGE);       
while (it.hasNext()) {
    ActionMessage msg = (ActionMessage) it.next();
    if (msgKey.equalsIgnoreCase(msg.getKey())) {
                // remove msgKey from warningMessages
    }
}