--- a/src/treecms/tree/util/NodeChildrenImpl.java	Mon Jun 06 21:49:04 2011 +0900
+++ b/src/treecms/tree/util/NodeChildrenImpl.java	Tue Jun 07 16:42:49 2011 +0900
@@ -6,14 +6,17 @@
 import java.util.Map;
 import java.util.Set;
 import java.util.concurrent.ConcurrentHashMap;
+import java.util.concurrent.ConcurrentMap;
 import java.util.concurrent.CopyOnWriteArrayList;
+
+import treecms.api.NodeAttributes;
 import treecms.api.NodeChildren;
 import treecms.api.NodeContext;
 import treecms.api.NodeID;
 
-public class NodeChildrenImpl<T extends NodeContext & NodeChildren<T>> implements NodeChildren<T>
+public class NodeChildrenImpl<T extends NodeContext & NodeAttributes & NodeChildren<T>> implements NodeChildren<T>
 {
-	private final Map<String,T> m_map;
+	private final ConcurrentMap<String,T> m_map;
 	private final List<T> m_list;
 	private final List<T> m_readOnlyList;
 	
@@ -54,6 +57,11 @@
 	}
 	
 	@Override
+	public T create(NodeAttributes _attr)
+	{
+		throw new UnsupportedOperationException();
+	}
+	
 	public synchronized T replace(T _node)
 	{
 		String fid = _node.getID().getFamilyID();
@@ -79,7 +87,6 @@
 		return null;
 	}
 	
-	@Override
 	public synchronized boolean add(T _n)
 	{
 		if(!m_map.containsKey(_n.getID().getFamilyID())){
@@ -89,7 +96,6 @@
 		return false;
 	}
 	
-	@Override
 	public synchronized boolean addAll(NodeChildren<T> _list)
 	{
 		if(_list == this){