def test_pop_and_peek(self):
stack = TripleStack()
for i in range(10):
stack.push(i % 3, i)
for i in range(9, -1, -1):
self.assertEquals(stack.pop(i % 3), i)
self.assertRaises(KeyError, stack.pop, 0)
self.assertEquals(stack.peek(0), None)
def test_push_and_peek(self):
stack = TripleStack()
for i in range(10):
stack.push(i % 3, i)
self.assertEquals(stack.peek(i % 3), i)
