private boolean removeAdmin(@Nonnull final JID userAddress, @Nonnull final Affiliation actorAffiliation) throws ForbiddenException
    {
        if (Affiliation.owner != actorAffiliation) {
            throw new ForbiddenException();
        }
        return admins.remove( userAddress.asBareJID() );
    }
Adds a new user to the list of admins.

@param targetUserAddress the (real) JID of the user to add as admin.
@param actorAffiliation The room affiliation the user that is trying to modify the admins 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 admin list.
@throws ConflictException If the room was going to lose all its owners.
xmppserver/src/main/java/org/jivesoftware/openfire/muc/MUCRoom.java