private void makeDispatcherSlow() {
    System.setProperty("slowStartTimeForTesting", "5000");
  }
This is to test the serialization mechanism of ClientUpdateMessage. Added after CQ support.
This could be done in different way, by overflowing the HARegion queue.
geode-cq/src/distributedTest/java/org/apache/geode/internal/cache/ha/HADispatcherDistributedTest.java