@Test
  public void testDeltaPropagationForPRFailover() throws Exception {
    int port1 =
        dataStore1.invoke(() -> createCacheServerWithPR(REGION_NAME, 1, 50, 8, false, null));
    int port2 =
        dataStore2.invoke(() -> createCacheServerWithPR(REGION_NAME, 1, 50, 8, false, null));

    // Do puts after slowing the dispatcher.
    dataStore1.invoke(() -> ConflationDistributedTestHelper.setIsSlowStart("60000"));
    dataStore2.invoke(() -> ConflationDistributedTestHelper.setIsSlowStart("60000"));
    createClientCache(port1, port2);
    client1.invoke(() -> createClientCache(port1, port2));

    int deltaSent = putsWhichReturnsDeltaSent();

    VM primary;
    VM secondary;
    if (pool.getPrimaryPort() == port1) {
      primary = dataStore1;
      secondary = dataStore2;
    } else {
      primary = dataStore2;
      secondary = dataStore1;
    }

    primary.invoke(JUnit4DistributedTestCase::disconnectFromDS);

    Thread.sleep(5000);

    secondary.invoke(ConflationDistributedTestHelper::unsetIsSlowStart);

    client1.invoke(this::waitForLastKey);
    client1.invoke(() -> checkDeltaInvoked(deltaSent));
  }
Check delta propagation works properly with PR failover.
geode-cq/src/distributedTest/java/org/apache/geode/internal/cache/PRDeltaPropagationDistributedTest.java