def test_subset():
    d = Interval(1, 3)
    assert d.is_subset_of((0, 4))
    assert d.is_subset_of((1, 3))
    assert (not d.is_subset_of(Interval.closed_open(1, 3)))
    assert d.is_superset_of((2, 2))
    assert d.is_superset_of((1, 3))
    assert d.is_superset_of(Interval.closed_open(1, 3))
def test_subset():
    d = Interval(1, 3)
    assert d.is_subset_of((0, 4))
    assert d.is_subset_of((1, 3))
    assert (not d.is_subset_of(Interval.closed_open(1, 3)))
    assert d.is_superset_of((2, 2))
    assert d.is_superset_of((1, 3))
    assert d.is_superset_of(Interval.closed_open(1, 3))