@Test
  public void testS2CDeltaPropagationFailedStats1() throws Exception {
    int numOfKeys = 25;
    long updates = 50;
    long errors = 100, errors2 = 34;
    Object[] args =
        new Object[] {Boolean.TRUE, DataPolicy.REPLICATE, Scope.DISTRIBUTED_ACK, Boolean.TRUE};
    int port =
        vm0.invoke(DeltaPropagationStatsDUnitTest.class, "createServerCache", args);

    createClientCache(NetworkUtils.getServerHostName(vm0.getHost()), port);

    vm0.invoke(() -> DeltaPropagationStatsDUnitTest.putErrorDeltaForReceiver(
        numOfKeys, updates, errors));
    vm0.invoke(() -> DeltaPropagationStatsDUnitTest.putErrorDeltaForSender(
        numOfKeys, updates, errors2, Boolean.FALSE));
    vm0.invoke(DeltaPropagationStatsDUnitTest::putLastKey);

    waitForLastKey();

    vm0.invoke(() -> DeltaPropagationStatsDUnitTest.verifyDeltaSenderStats(
        SERVER_TO_CLIENT, 2 * numOfKeys * updates - errors2));
    verifyDeltaReceiverStats(SERVER_TO_CLIENT, 2 * numOfKeys * updates - errors - errors2, errors);
  }
Simulates error in fromDelta() and toDelta()
geode-core/src/distributedTest/java/org/apache/geode/internal/cache/DeltaPropagationStatsDUnitTest.java