@Nullable
    public MultiUserChatService getMultiUserChatService(final long serviceID) {
        final String subdomain = getMultiUserChatSubdomain(serviceID);
        if (subdomain == null) {
            return null;
        }
        return mucServices.get(subdomain);
    }
Retrieves a MultiUserChatService instance specified by it's service ID.

@param serviceID ID of the conference service you wish to query.
@return The MultiUserChatService instance associated with the id, or null if none found.
xmppserver/src/main/java/org/jivesoftware/openfire/muc/MultiUserChatManager.java