public abstract FetchedAppReport getApplicationReport(ApplicationId appId)
      throws YarnException, IOException;
@Test
  void testFetchReportAHSEnabled() throws YarnException, IOException {
    testHelper(true);
    Mockito.verify(historyManager, Mockito.times(1))
        .getApplicationReport(Mockito.any(GetApplicationReportRequest.class));
    Mockito.verify(appManager, Mockito.times(1))
        .getApplicationReport(Mockito.any(GetApplicationReportRequest.class));
  }