@Override
  public String toString() {
    if (clientUpdateMessage != null) {
      return "HAEventWrapper[refCount=" + getReferenceCount() + "; putInProgress="
          + putInProgressCountUpdater.get(this) + "; msg=" + clientUpdateMessage + "]";
    } else {
      return "HAEventWrapper[region=" + regionName + "; key=" + keyOfInterest
          + "; refCount=" + getReferenceCount()
          + "; putInProgress=" + putInProgressCountUpdater.get(this) + "; event="
          + eventIdentifier
          + ((clientUpdateMessage == null) ? "; no message" : ";with message")
          + ((clientUpdateMessage == null) ? ""
              : ("; op=" + clientUpdateMessage.getOperation()))
          + ((clientUpdateMessage == null) ? ""
              : ("; version=" + clientUpdateMessage.getVersionTag()))
          + "]";
    }
  }
Returns the hash code of underlying event id.

@return int The hash code of underlying EventID instance.
geode-core/src/main/java/org/apache/geode/internal/cache/tier/sockets/HAEventWrapper.java