### Question:
ShutdownThreadsHelper { public static boolean shutdownExecutorService(ExecutorService service) throws InterruptedException { return shutdownExecutorService(service, SHUTDOWN_WAIT_MS); }  static boolean shutdownThread(Thread thread); static boolean shutdownThread(Thread thread,
                                    long timeoutInMilliSeconds); static boolean shutdownExecutorService(ExecutorService service); static boolean shutdownExecutorService(ExecutorService service,
                                        long timeoutInMs);  }### Answer:
@Test public void testShutdownThreadPool() throws InterruptedException { ScheduledThreadPoolExecutor executor = new ScheduledThreadPoolExecutor(1); executor.execute(sampleRunnable); boolean ret = ShutdownThreadsHelper.shutdownExecutorService(executor); boolean isTerminated = executor.isTerminated(); assertEquals("Incorrect return value", ret, isTerminated); assertTrue("ExecutorService is not shutdown", isTerminated); }