The TestSuiteBuilder.FailedToCreateTests class is a special TestCase class used to indicate a failure during the build() step. That is, during the test suite creation, if an error is detected, you will receive an exception like this one, which indicates the failure to construct the test suite:
INFO/TestRunner(1): java.lang.RuntimeException: Exception during suite construction INFO/TestRunner(1): at android.test.suitebuilder.TestSuiteBuilder$FailedToCreateTests.testSuiteConstructionFailed(TestSuiteBuilder.java:239) INFO/TestRunner(1): at java.lang.reflect.Method.invokeNative(Native Method) [...] INFO/TestRunner(1): at android.test.InstrumentationTestRunner.onStart(InstrumentationTestRunner.java:520) INFO/TestRunner(1): at android.app.Instrumentation$InstrumentationThread.run(Instrumentation.java:1447)