def test_invert(self):
s = Span(0, 1000, 1000, cyclic=True)
assert s.contains_pos(1)
s2 = s.invert()
assert len(s2[0]) == 0
def test_full_wrap_sub_region(self):
s = Span(0, 1000, 1000, cyclic=True)
assert s.contains_pos(1)
s2 = s.sub(500, 600)
assert s2.a == 500
assert s2.b == 600