private void initializeId(EntryEventImpl event) {
    // CS43_HA
    id = event.getEventId();
    // TODO:ASIF :Once stabilized remove the check below
    if (id == null) {
      throw new IllegalStateException(
          "No event id is available for this gateway event.");
    }

  }
Initialize the unique identifier for this event. This id is used by the receiving
<code>Gateway</code> to keep track of which events have been processed. Duplicates can be
dropped.
geode-core/src/main/java/org/apache/geode/internal/cache/wan/GatewaySenderEventImpl.java