This is mainly a class that holds common code for other test cases that access Instrumentation.
You can use this class if you are implementing a specific behavior for test cases and the existing alternatives don't fit your requirements. This means you are unlikely to use this class unless you want to implement a new base class for other tests to use. For example, consider a scenario where Google brings out a new component and you want to write tests around it (like SuperNewContentProvider).
If this is not the case, you might find the following options more suitable for your requirements:
ActivityInstrumentationTestCase2<T extends Activity>ActivityUnitTestCase<T extends Activity>
The abstract class android.test.ActivityTestCase extends android.test.InstrumentationTestCase and serves as a base class for other different test cases, such as android.test.ActivityInstrumentationTestCase, android.test.ActivityInstrumentationTestCase2, and android.test.ActivityUnitTestCase...