code: def run(self):
      # checking the existence of the file - this file had been added to the custom base image
      assert ".e2e_test" in os.listdir("/testdir/"), "file not found"
  
file_path: pytorch-lightning/tests/integrations_app/apps/custom_work_dependencies/app.py
imports: import os
  from lightning.app import BuildConfig, CloudCompute, LightningApp, LightningFlow, LightningWork
label_desc: Use image node_id 2 for calling the WorkWithCustomBaseImage obj's underlying member method code with example usage: obj.run() without return types