code: def run(self):
      self.src.run()
      self.dst.run(self.src.value)
      self.stop("Application End!")
  
file_path: pytorch-lightning/examples/app/payload/app.py
imports: from lightning.app import LightningApp, LightningFlow, LightningWork
  from lightning.app.storage import Payload
label_desc: Use image node_id 2 for calling the RootFlow obj's underlying member method code with example usage: obj.run() without return types