These situations often call for special schemas defining information for every specific error, thus effectively extending domain semantic model to describe failure scenarios.
These conditions represent the failure modes of the program — they are implementation related and have nothing to do with the problem domain, so they don't belong in a use-case analysis.
这些条件表示程序的失败方式——它们与实现相关，但与问题领域无关，因此它们不属于用例分析。
3
This time, however, the failure isn't due to the lack of metaprogramming on a domain class. It's due to the lack of dependency injection.