code: def run(self):
      print("Hello World!" if self.streamlit_ui.should_print else "")
  
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 2 for calling the HelloWorld obj's underlying member method code with example usage: obj.run() without return types