@Test
  public void testSecondaryFailureInUNRegisterInterest() throws Exception {
    createClientPoolCache(getName(), NetworkUtils.getServerHostName(server1.getHost()));
    createEntriesK1andK2();
    server1.invoke(HAInterestTestCase::createEntriesK1andK2);
    server2.invoke(HAInterestTestCase::createEntriesK1andK2);
    server3.invoke(HAInterestTestCase::createEntriesK1andK2);
    registerK1AndK2();
    VM stoppedBackup = stopSecondaryAndUNregisterK1();
    verifyDeadAndLiveServers(1, 2);
    // still primary
    getPrimaryVM().invoke(HAInterestTestCase::verifyDispatcherIsAlive);
    // primary
    getPrimaryVM().invoke(HAInterestTestCase::verifyInterestUNRegistration);
    // secondary
    getBackupVM(stoppedBackup).invoke(HAInterestTestCase::verifyInterestUNRegistration);
  }
Tests if Secondary fails during interest un registration should add to dead Ep list
geode-core/src/distributedTest/java/org/apache/geode/internal/cache/tier/sockets/HAInterestPart2DUnitTest.java