'When more events than a L{LimitedHistoryLogObserver}\'s maximum size are
buffered, older events will be dropped.'

def test_limit(self):

    size = 4
    events = [dict(n=n) for n in range((size * 2))]
    observer = LimitedHistoryLogObserver(size)
    for event in events:
        observer(event)
    outEvents = []
    observer.replayTo(outEvents.append)
    self.assertEqual(events[(- size):], outEvents)
