Update app.py

app.py

@@ -82,8 +82,7 @@ graph = Neo4jGraph(
 
 
 chain = GraphCypherQAChain.from_llm(
-    cypher_llm=VertexAI(model_name='code-bison@001', max_output_tokens=2048, temperature=0.0),
-    qa_llm=VertexAI(model_name='text-bison', max_output_tokens=2048, temperature=0.0),
+    VertexAI(model_name='code-bison@002', max_output_tokens=2048, temperature=0.0),
     graph=graph,
     cypher_prompt=CYPHER_GENERATION_PROMPT,
     verbose=True,