Update unit2/langgraph/mail_sorting.ipynb (#98)

- Update unit2/langgraph/mail_sorting.ipynb (d116020dca261d1c5762d9b29f1cd1453f670ff3)


Co-authored-by: S <[email protected]>

unit2/langgraph/mail_sorting.ipynb

@@ -50,7 +50,7 @@
    "source": [
     "import os\n",
     "from typing import TypedDict, List, Dict, Any, Optional\n",
-    "from langgraph.graph import StateGraph, END\n",
+    "from langgraph.graph import StateGraph, START, END\n",
     "from langchain_openai import ChatOpenAI\n",
     "from langchain_core.messages import HumanMessage\n",
     "\n",