ExecutorServiceWithTracing implements ExecutorService { @Override public void shutdown() { delegate.shutdown(); } ExecutorServiceWithTracing(ExecutorService delegate); static ExecutorServiceWithTracing withTracing(ExecutorService delegate); @Override void shutdown(); @Override List<Runnable> shutdownNow(); @Override boolean isShutdown(); @Override boolean isTerminated(); @Override boolean awaitTermination(long timeout, TimeUnit unit); @Override Future<T> submit(Callable<T> task); @Override Future<T> submit(Runnable task, T result); @Override Future<?> submit(Runnable task); @Override List<Future<T>> invokeAll(Collection<? extends Callable<T>> tasks); @Override List<Future<T>> invokeAll(
        Collection<? extends Callable<T>> tasks, long timeout, TimeUnit unit
    ); @Override T invokeAny(Collection<? extends Callable<T>> tasks); @Override T invokeAny(
        Collection<? extends Callable<T>> tasks, long timeout, TimeUnit unit
    ); @Override void execute(Runnable command);  }
@Test public void shutdown_passes_through_to_delegate() { instance.shutdown(); verify(executorServiceMock).shutdown(); verifyNoMoreInteractions(executorServiceMock); }