@Test
  public void testReplicatedRegionWithGatewaySenderPersistenceEnabled() {

    Integer lnPort = vm0.invoke(() -> WANTestBase.createFirstLocatorWithDSId(1));
    Integer nyPort = vm1.invoke(() -> WANTestBase.createFirstRemoteLocator(2, lnPort));

    createCacheInVMs(nyPort, vm2, vm3);
    createReceiverInVMs(vm2, vm3);

    createCacheInVMs(lnPort, vm4, vm5, vm6, vm7);

    vm4.invoke(() -> WANTestBase.createSender("ln", 2, false, 100, 10, false, true, null, true));
    vm5.invoke(() -> WANTestBase.createSender("ln", 2, false, 100, 10, false, true, null, true));

    vm2.invoke(
        () -> WANTestBase.createReplicatedRegion(getTestMethodName() + "_RR", null, isOffHeap()));
    vm3.invoke(
        () -> WANTestBase.createReplicatedRegion(getTestMethodName() + "_RR", null, isOffHeap()));

    startSenderInVMs("ln", vm4, vm5);

    vm4.invoke(
        () -> WANTestBase.createReplicatedRegion(getTestMethodName() + "_RR", "ln", isOffHeap()));
    vm5.invoke(
        () -> WANTestBase.createReplicatedRegion(getTestMethodName() + "_RR", "ln", isOffHeap()));
    vm6.invoke(
        () -> WANTestBase.createReplicatedRegion(getTestMethodName() + "_RR", "ln", isOffHeap()));
    vm7.invoke(
        () -> WANTestBase.createReplicatedRegion(getTestMethodName() + "_RR", "ln", isOffHeap()));

    vm4.invoke(() -> WANTestBase.doPuts(getTestMethodName() + "_RR", 1000));

    vm2.invoke(() -> WANTestBase.validateRegionSize(getTestMethodName() + "_RR", 1000));
    vm3.invoke(() -> WANTestBase.validateRegionSize(getTestMethodName() + "_RR", 1000));

  }
Just enable the persistence for GatewaySender and see if it remote site receives all the
events.
geode-wan/src/distributedTest/java/org/apache/geode/internal/cache/wan/serial/SerialWANPersistenceEnabledGatewaySenderDUnitTest.java