change build_graph to build_graph()

app.py

@@ -17,10 +17,11 @@ langfuse_handler = CallbackHandler()
 class BasicAgent:
     def __init__(self):
         print("BasicAgent initialized.")
-        self.graph = build_graph
+        self.graph = build_graph()
     def __call__(self, question: str) -> str:
         print(f"Agent received question (first 50 chars): {question[:50]}...")
         messages = [HumanMessage(content=question)]
+        print(f"Message = {messages}")
         messages = self.graph.invoke({"messages": messages})
         messages = self.graph.invoke({"messages": messages},config={"callbacks": [langfuse_handler]})
         self.graph.get_graph().draw_mermaid_png()