def METHOD_NAME(output_dir, configuration):
  """create unsigned .ipa from .app, then remove .app afterwards
  Args:
    output_dir (str): Same value as get_args_for_build. generated unsigned .ipa 
      will be placed within the subdirectory "Debug-iphoneos" or "Release-iphoneos".
    configuration (str): Same value as get_args_for_build.
  """
  iphone_build_dir = os.path.join(output_dir, configuration + "-iphoneos")
  payload_path = os.path.join(iphone_build_dir, "Payload")
  app_path = os.path.join(iphone_build_dir, "integration_test.app")
  ipa_path = os.path.join(iphone_build_dir, "integration_test.ipa")
  os.mkdir(payload_path)
  shutil.move(app_path, payload_path)
  shutil.make_archive(payload_path, 'zip', root_dir=iphone_build_dir, base_dir='Payload')
  shutil.move('%s.%s'%(payload_path, 'zip'), ipa_path)
  shutil.rmtree(payload_path)