title: abstract test case using python unittest
body: <p>Is it possible to create an abstract <code>TestCase</code>, that will have some test_* methods, but this <code>TestCase</code> won't be called and those methods will only be used in subclasses? I think I am going to have one abstract <code>TestCase</code> in my test suite and it will be subclassed for a few different implementation of a single interface. This is why all test methods are the some, only one, internal method changes. How can I do it in elegant way?</p>