Traceback (most recent call last):
  File "/Users/magicliang/Desktop/Programming/git/hexo-blog/examples/system-design/labs/35/session-dispatch/cancel_cache_naive.py", line 24, in <module>
    assert changed==0,'cached offered state resurrected a committed cancellation'
           ^^^^^^^^^^
AssertionError: cached offered state resurrected a committed cancellation
