code: def run(self):
      # pretend to train and save a checkpoint every 10 steps
      for step in range(1000):
          time.sleep(1.0)
          if step % 10 == 0:
              self.msg_changed = True
              self.new_msg = f"A is at step: {step}"
              print(self.new_msg)
  
file_path: pytorch-lightning/docs/source-app/levels/intermediate/scripts/two_comms_non_ml.py
imports: from lightning.app import LightningWork, LightningFlow, LightningApp
  import time
label_desc: Use image node_id 2 for calling the A obj's underlying member method code with example usage: obj.run() without return types