private void sendSubscribeRequest(JID sender, JID recipient, boolean isSubscribe) {
        Presence presence = new Presence();
        presence.setFrom(sender);
        presence.setTo(recipient);
        if (isSubscribe) {
            presence.setType(Presence.Type.subscribe);
        }
        else {
            presence.setType(Presence.Type.unsubscribe);
        }
        routingTable.routePacket(recipient, presence);
    }
Notification that a Group user has been deleted. Update the group users' roster accordingly.

@param group the group from where the user was deleted.
@param users the users to update their rosters
@param deletedUser the username of the user that has been deleted from the group.
xmppserver/src/main/java/org/jivesoftware/openfire/roster/RosterManager.java