public static AccessModel valueOf(String name) {
        if ("open".equals(name)) {
            return open;
        }
        else if ("whitelist".equals(name)) {
            return whitelist;
        }
        else if ("authorize".equals(name)) {
            return authorize;
        }
        else if ("presence".equals(name)) {
            return presence;
        }
        else if ("roster".equals(name)) {
            return roster;
        }
        throw new IllegalArgumentException("Unknown access model: " + name);
    }
Returns the specific subclass of AccessModel as specified by the access
model name. If an unknown name is specified then an IllegalArgumentException
is going to be thrown.

@param name the name of the subclass.
@return the specific subclass of AccessModel as specified by the access
        model name.
xmppserver/src/main/java/org/jivesoftware/openfire/pubsub/models/AccessModel.java