def test_s0():
assert list(Permutation.group(0)) == [Permutation()]
assert list(Permutation.group(1)) == [Permutation()]
def test_bad_group():
with pytest.raises(ValueError):
Permutation.group(-1)
def test_s4():
for i, (p, q) in enumerate(zip_longest(Permutation.group(4), S4)):
assert p == q
assert p.left_lehmer() == i
