Removing the user filter means that any user can abandon the task attempt of any other user, so that needs to go back in. This gets even simpler, however, once we change the model to TaskAttempt.

The `get_queryset` method from `SingleObjectMixin` lets you return the queryset that will limit what TaskAttempts are available. So you can use `get_queryset` to return a TaskAttempt queryset filtered by the user and the state. The class will automatically handle picking out the `pk` from the kwargs, so you just need to call `self.get_object()` to get the correct taskattempt.