@Test
  public void startShutdownTest() throws IOException {
    final int EXPECTED_WORKER_COUNT = new Random().nextInt(10);
    AsyncRequestResponseHandler handler = getAsyncRequestResponseHandler(EXPECTED_WORKER_COUNT);
    assertEquals("Number of workers alive is incorrect", 0, handler.getWorkersAlive());
    assertFalse("IsRunning should be false", handler.isRunning());
    handler.start();
    try {
      assertTrue("IsRunning should be true", handler.isRunning());
      assertEquals("Number of workers alive is incorrect", EXPECTED_WORKER_COUNT, handler.getWorkersAlive());
    } finally {
      handler.shutdown();
    }
    assertFalse("IsRunning should be false", handler.isRunning());
  }
Tests {@link AsyncRequestResponseHandler#start()} and {@link AsyncRequestResponseHandler#shutdown()}.
@throws IOException
ambry-rest/src/test/java/com/github/ambry/rest/AsyncRequestResponseHandlerTest.java