The test case starts off by scheduling a timer task using the DefaultTimeScheduler and then sleeping, waiting for the task to execute

Instead of the task being executed, the call to sleep is interrupted and the test case fails with an interrupted exception. Catching this interrupted exception shows that the task has not had a chance to execute before the sleep was interrupted.

The same test case passes with the other two TimeScheduler implementations: TimeScheduler2 and HashedTimingWheel.