public boolean hasDirectPresence(JID ownerJID, JID recipientJID) {
        if (recipientJID == null) {
            return false;
        }
        Collection<DirectedPresence> directedPresences = directedPresencesCache.get(ownerJID.toString());
        if (directedPresences != null) {
            String recipient = recipientJID.toBareJID();
            for (DirectedPresence directedPresence : directedPresences) {
                for (String receiver : directedPresence.getReceivers()) {
                    if (receiver.contains(recipient)) {
                        return true;
                    }
                }
            }
        }
        return false;
    }
Sends an unavailable presence to the entities that sent a directed (available) presence
to other entities.

@param update the unavailable presence sent by the user.
xmppserver/src/main/java/org/jivesoftware/openfire/handler/PresenceUpdateHandler.java