private boolean removeOwner(@Nonnull final JID userAddress, @Nonnull final Affiliation actorAffiliation) throws ForbiddenException
    {
        if (Affiliation.owner != actorAffiliation) {
            throw new ForbiddenException();
        }

        return owners.remove(userAddress.asBareJID());
    }
Adds a new user to the list of owners.

@param targetUserAddress the (real) JID of the user to add as owner.
@param actorAffiliation the room affiliation of the user that is trying to modify the owners list.
@return the list of updated presences of all the client resources that the client used to
        join the room.
@throws ForbiddenException If the user is not allowed to modify the owner list.
xmppserver/src/main/java/org/jivesoftware/openfire/muc/MUCRoom.java