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After a while you want to refactor your class A. You also change the mapping A.hbm.xml. But the test ReadVersion1_5 you wrote on release now fails because reading the old db with the new a.hbm.xml does not work! What to do? You can chose not to refactor A and do something else OR you could add a A.hbm.1.5.hbm.xml mapping that converts the old db to the new object. Once you check in that new mapping file *ReadVersion1.5 should use that specific file (instead of A.hbm.xml) and the test should pass again.
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