def test_after_returns_None_with_passed_last_Position_in_list(self):
pl = PositionalList()
# create two nodes with proper references in the container:
n1 = PositionalList._Node('foo', pl._header, pl._trailer)
n2 = PositionalList._Node('bar', n1, pl._trailer)
n1._next = n2
pl._header._next = n1
pl._trailer._prev = n2
p2 = PositionalList.Position(pl, n2)
result = pl.after(p2)
self.assertIsNone(result)
def test_after_returns_Position_after_passed_Position(self):
pl = PositionalList()
# create two nodes with proper references in the container:
n1 = PositionalList._Node('foo', pl._header, pl._trailer)
n2 = PositionalList._Node('bar', n1, pl._trailer)
n1._next = n2
pl._header._next = n1
pl._trailer._prev = n2
# # create a position for each respective node:
p1 = PositionalList.Position(pl, n1)
p2 = PositionalList.Position(pl, n2)
result = pl.after(p1)
self.assertEqual(result, p2)