code: def render_fn(state: AppState):
      import streamlit as st
      from streamlit_autorefresh import st_autorefresh
  
      st_autorefresh(interval=2000, limit=None, key="refresh")
  
      state.should_print = st.select_slider(
          "Should the Application print 'Hello World !' to the terminal:",
          [False, True],
      )
  
file_path: pytorch-lightning/docs/source-app/code_samples/quickstart/hello_world/app_ui.py
imports: import os
  from lightning.app import LightningFlow, LightningApp
  from lightning.app.frontend import StaticWebFrontend, StreamlitFrontend
  from lightning.app.utilities.state import AppState
label_desc: Use image node_id 1 for calling a global function with example usage: render_fn(state) without return types