@Test
  public void shutdownWithoutStartTest() {
    FrontendRestRequestService frontendRestRequestService = getFrontendRestRequestService();
    frontendRestRequestService.shutdown();
  }
Tests for {@link FrontendRestRequestService#shutdown()} when {@link FrontendRestRequestService#start()} has not been
called previously.
<p/>
This test is for  cases where {@link FrontendRestRequestService#start()} has failed and
{@link FrontendRestRequestService#shutdown()} needs to be run.
ambry-frontend/src/test/java/com/github/ambry/frontend/FrontendRestRequestServiceTest.java