Traceback (most recent call last):
  File "/Users/magicliang/Desktop/Programming/git/hexo-blog/examples/enterprise-application-architecture/labs/23/lab.py", line 117, in <module>
    main()
    ~~~~^^
  File "/Users/magicliang/Desktop/Programming/git/hexo-blog/examples/enterprise-application-architecture/labs/23/lab.py", line 93, in main
    assert amount == 300, "duplicate-refund"
           ^^^^^^^^^^^^^
AssertionError: duplicate-refund
