You must provide your own tests in the file StudentTests.java provided with the code distribution. You only need to provide tests for methods that you implement or that call methods that you implement. The submit server provides information regarding methods that are not covered by public or student's tests; please look at this information while developing your tests. Notice that even though a public test may exist for a method, the test may not test the method for all the possible arguments it can accept. Therefore, add tests for methods even if they are already tested in a public test.
We encourage you to thoroughly test your code with your own tests. This will allow you to pass the release tests sooner plus will help you develop your testing skills (after all, there is no submit server in the real world :)). In addition, you should implement your tests as you develop your code.
If you define any text files for your tests, you must name those files beginning with "studentTest" and ending with the .txt extension. If you don't name files this way, the submit server will generate an authorization error (even if the tests run fine in Eclipse). By the way, while developing your tests, feel free to use any code we have provided in the test package of the code distribution.
Keep in mind that your can use the debugger with JUnit tests.