LimitedHistory should override extend. #1451
Description
LimitedHistory inherits extend from base class. However expected behavior is that LimitedHistory only keeps the last memory_depth history.
Should make this unittest on TestLimitedHistory pass.
def test_extend(self):
h1 = LimitedHistory(3, plays=[C, C, D], coplays=[C, C, C])
self.assertEqual(list(h1), [C, C, D])
h1.extend([C, C], [D, D])
self.assertEqual(list(h1), [D, C, C])