@Override
    public void initialize(XMPPServer server) {
        super.initialize(server);
        presenceManager = server.getPresenceManager();
    }
Implements the TYPE_IQ jabber:iq:last protocol (last activity). Allows users to find out
the number of seconds another user has been offline. This information is only available to
those users that already subscribed to the users presence. Otherwhise, a {@code forbidden}
error will be returned.

@author Gaston Dombiak
xmppserver/src/main/java/org/jivesoftware/openfire/handler/IQLastActivityHandler.java