Sequence-based comparative maps

Therefore, we have two options. We can write a test harness that performs the requisite sequences and checks the postconditions by comparing states before and after, or we can perform the equivalent checks manually by following a written test procedure. This is a matter of policy in your project. Each approach will be appropriate in different circumstances. Either way, you are systematically defining test sequences based on refinement of abstract actions. And, either way, the documented action conformance should be used to guide the creation of the tests, and the retrievals (whether only documented or actually coded as we saw earlier) provide the mapping between the different levels of the model. 

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