code: def addStep(self, callback, *args, **kwargs):
      '''
      Add rollback step with optional arguments. If a rollback is
      triggered, each step is called in LIFO order.
      '''
      self.steps.append((callback, args, kwargs)f addStep(self, callback, *args, **kwargs):
      '''
      Add rollback step with optional arguments. If a rollback is
      triggered, each step is called in LIFO order.
      '''
      self.steps.append((callback, args, kwargs))
docs: Add rollback step with optional arguments. If a rollback is
      triggered, each step is called in LIFO order.