public boolean isPersistent() {
        return persistent;
    }
Returns true if the room is not destroyed if the last occupant exits. Persistent rooms are
saved to the database to make their configurations persistent together with the affiliation
of the users.

@return true if the room is not destroyed if the last occupant exits.
xmppserver/src/main/java/org/jivesoftware/openfire/muc/MUCRoom.java