@Override
    public void writeExternal(ObjectOutput out) throws IOException {
        ExternalizableUtil.getInstance().writeInt(out, event.ordinal());
        ExternalizableUtil.getInstance().writeSafeUTF(out, key);
        ExternalizableUtil.getInstance().writeBoolean(out, value != null);
        if (value != null) {
            ExternalizableUtil.getInstance().writeSafeUTF(out, value);
            ExternalizableUtil.getInstance().writeBoolean(out, isEncrypted);
        }
    }
This task updates or deletes a property in a cluster node's property map.
{@link PropertyEventListener} of each cluster node will be alerted of the event.

@author Gaston Dombiak
xmppserver/src/main/java/org/jivesoftware/util/PropertyClusterEventTask.java