fix __iter__ for ListNode

1 files changed, 3 insertions, 1 deletions

diff --git a/tree.py b/tree.py
index a69a851..435b3f0 100644
--- a/tree.py
+++ b/tree.py
@@ -268,7 +268,9 @@ class ListNode(VNode, list_class):
         """add a node to children"""
         child = list_class.pop(self, index)
         child.parent = None
-        
+
+    def __iter__(self):
+        return list_class.__iter__(self)
 
 # construct list from tree ####################################################