def add_sibling(self, pos=None, **kwargs):  # pragma: no cover
        raise NotImplementedError
test that our post-setup TorInfo pretends to only have
dataset/ETHPy150Open tabo/django-treebeard/treebeard/models.py/Node.add_sibling--crossover with--dataset/ETHPy150Open meejah/txtorcon/test/test_torinfo.py/InfoTests.test_attribute_access