def test_conversions():
t = range(10, 1, -1)
r = Range.from_range(t)
assert r.left == 10
assert r.right == 2
assert r.direction == "downto"
assert r.to_range() == t
def test_bad_step():
with pytest.raises(ValueError):
Range.from_range(range(10, 5, -2))