1. Have Node.removeChild() return true if the node was removed 2. Add a Node.size() or Node.dataSize() to count basically getData().size(). The problem (in terms of efficiency) is that getData() makes a copy. 3. Node.putIfAbsent() should be consistent with ConcurrentMap, and return Object. Consider adding other methods of ConcurrentMap. 4. Change Node.put to Node.putAll to be consistent with Map.putAll(). I'm working on a Node -> Map adaptor, sort of a poor man's PojoCache, and find these basic methods missing. View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4003572#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...