private void incrementTailKey() throws CacheException {
    tailKey.set(inc(tailKey.get()));
    if (logger.isTraceEnabled()) {
      logger.trace("{}: Incremented TAIL_KEY for region {} to {}", this, region.getName(),
          tailKey);
    }
  }
Increments the value of the tail key by one.
geode-core/src/main/java/org/apache/geode/internal/cache/wan/serial/SerialGatewaySenderQueue.java