@Override
    public void writeExternal(ObjectOutput out) throws IOException {
        ExternalizableUtil.getInstance().writeBoolean(out, authenticated);
    }
Task that will be executed in cluster nodes to get the number of sessions hosted by the
cluster node.

@author Gaston Dombiak
xmppserver/src/main/java/org/jivesoftware/openfire/session/GetSessionsCountTask.java