Add function return type

app.py

@@ -3,6 +3,7 @@ For more information on `huggingface_hub` Inference API support,
 please check the docs: https://huggingface.co/docs/huggingface_hub/v0.22.2/en/guides/inference
 """
 
+from typing import Any, Generator
 import gradio as gr
 from huggingface_hub import InferenceClient
 
@@ -16,7 +17,7 @@ def respond(
     max_tokens: int,
     temperature: float,
     top_p: float,
-):
+) -> Generator[Any, Any, None]:
     messages = [{"role": "system", "content": system_message}]
 
     for val in history: