def test_add_already_added(self):
        prio_set_list = event._PrioritizedSetList()
        obj = object()
        prio_set_list.add(0, obj)

        with pytest.raises(ValueError) as excinfo:
            prio_set_list.add(0, obj)
        excinfo.match(r"has already been added")

        with pytest.raises(ValueError) as excinfo:
            prio_set_list.add(1, obj)
        excinfo.match(r"has already been added")
def update_snapshot_status(self, snapshot_id, status, progress):
        """Update the specified snapshot's status."""
        post_body = {
            'status': status,
            'progress': progress
        }
        post_body = json.dumps({'os-update_snapshot_status': post_body})
        url = 'snapshots/%s/action' % str(snapshot_id)
        resp, body = self.post(url, post_body)
        return resp, body