protected boolean expire(boolean isPending) throws CacheException {
    ExpirationAction action = getAction();
    if (action == null) {
      return false;
    }
    boolean result = expire(action, isPending);
    if (result && expiryTaskListener != null) {
      expiryTaskListener.afterExpire(this);
    }
    return result;
  }
Wait until permission is given for expiration to be done. Tests are allowed to suspend
expiration.

@since GemFire 5.0
geode-core/src/main/java/org/apache/geode/internal/cache/ExpiryTask.java