JUnit is a framework for testing parts, or units of your code. In general, these units are considered to be the methods of each class. JUnit can help you to make sure that each of your classes work as expected. In unit testing you will usually write one test class for each of the classes that you want to test. Your test class will often include a test method for each method implemented by the class being tested. But keep in mind that this is not always feasible, or necessary. A test case will, and should often touch on more than a single method. These tests should be written to make it likely that when all the tests pass, the code is functioning as required.
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