protected void processPresence(Presence packet) throws UnauthorizedException {
        router.route(packet);
        session.incrementClientPacketCount();
    }
Process the received Presence packet. Registered
{@link org.jivesoftware.openfire.interceptor.PacketInterceptor} will be invoked before
and after the packet was routed.
<p>
Subclasses may redefine this method for different reasons such as modifying the sender
of the packet to avoid spoofing, rejecting the packet or even process the packet in
another thread.</p>

@param packet the received packet.
@throws org.jivesoftware.openfire.auth.UnauthorizedException
         if service is not available to sender.
xmppserver/src/main/java/org/jivesoftware/openfire/net/StanzaHandler.java