def METHOD_NAME(category_family):
    grandpa, dad, son, sibling = category_family
    assert son.nth_parent(0) == son
    assert son.nth_parent(1) == dad
    assert son.nth_parent(2) == grandpa
    assert dad.nth_parent(0) == dad
    assert dad.nth_parent(1) == grandpa
    assert sibling.nth_parent(2) == grandpa
    assert sibling.nth_parent(0) != son.nth_parent(0)
    assert sibling.nth_parent(1) == son.nth_parent(1)
    assert sibling.nth_parent(2) == son.nth_parent(2)
    pytest.raises(IndexError, grandpa.nth_parent, 1)
    pytest.raises(IndexError, dad.nth_parent, 2)
    pytest.raises(IndexError, son.nth_parent, 3)
    pytest.raises(IndexError, grandpa.nth_parent, 100)