CallbackSchedulerImpl implements CallbackScheduler { @Override public <K> void deleteCallback(K key) { this.epochTimeScheduler.deleteTimer(key); } CallbackSchedulerImpl(EpochTimeScheduler epochTimeScheduler); @Override void scheduleCallback(K key, long timestamp, ScheduledCallback<K> callback); @Override void deleteCallback(K key);  }
@Test public void testDeleteCallback() { scheduler.deleteCallback("string_key"); verify(epochTimeScheduler).deleteTimer("string_key"); scheduler.deleteCallback(777); verify(epochTimeScheduler).deleteTimer(777); }