private static void setEventIdIfNew(final Instantiator instantiator) {
    final InternalCache cache = getInternalCache();
    if (cache != null && instantiator.getEventId() == null) {
      instantiator.setEventId(new EventID(cache.getDistributedSystem()));
    }
  }
if instantiator is getting registered for first time its EventID will be null, so generate a
new event id the the distributed system is connected
geode-core/src/main/java/org/apache/geode/internal/InternalInstantiator.java