UPDATE: chat history retention

functions.py

@@ -159,9 +159,9 @@ def format_docs(docs: str):
 
 
 def get_session_history(session_id: str) -> BaseChatMessageHistory:
-    if session_id not in store:
-        store[session_id] = ChatMessageHistory()
-    return store[session_id]
+    if session_id not in chatHistoryStore:
+        chatHistoryStore[session_id] = ChatMessageHistory()
+    return chatHistoryStore[session_id]
 
 
 def trimMessages(chain_input):