### Question:
DefaultPlaceExecutorRegistry implements PlaceExecutorRegistry { @Override public void clear() { executors.invalidateAll(); } @Inject  DefaultPlaceExecutorRegistry(
         Clock clock,
         PlaceExecutorFactory factory
   ); @PreDestroy void stop(); boolean isCached(UUID placeId); @Override Optional<PlaceEnvironmentExecutor> getExecutor(UUID placeId); @Override void start(UUID placeId); @Override void reload(UUID placeId); @Override boolean stop(UUID placeId); @Override void clear();  }### Answer:
@Test public void testClear() { expectLoadPlace(placeId); expectExecutorStop(); replay(); registry.start(placeId); registry.clear(); verify(); }