public Long getMultiUserChatServiceID(@Nonnull final String subdomain) {
        return loadServiceID(subdomain);
    }
Retrieves the database ID of a MUC service by subdomain.

@param subdomain Subdomain of service to get ID of.
@return ID number of MUC service, or null if none found.
xmppserver/src/main/java/org/jivesoftware/openfire/muc/MultiUserChatManager.java