Update ordered_multimap_weakref.py

ordered_multimap_weakref.py

@@ -1,14 +1,14 @@
-import weakref
+from weak_list import WeakList
 from collections import defaultdict
 
 class OrderedMultimapWeakRef:
     def __init__(self):
         self.data = []
-        self.index_map = weakref.WeakValueDictionary()
+        self.index_list = WeakList()
 
     def insert(self, text, title):
         self.data.append(text)
-        self.index_map[len(self.data)-1] = title
+        self.index_list.append(title)
 
     def get(self, key):
         if key: