Update rag_langgraph.py

rag_langgraph.py

@@ -130,4 +130,8 @@ def create_graph(topic, word_count):
 
 def run_multi_agent(topic, word_count):
     graph = create_graph(topic, word_count)
-    result = graph.invoke({"question": "Code hello world and print it to the terminal"})
+    result = graph.invoke({
+        "messages": [
+            HumanMessage(content="Code hello world and print it to the terminal")
+        ]
+    }