function sixd(options){
	var observers = [];
	var me = this;
	function notifySetObserversFor(key, value){
        var ubounds = observers.length;
        var indexer = 0;
        for(indexer; indexer < ubounds; indexer++){
            if(observers[indexer].observer.observerKeyValueSet !== undefined){
				if(observers[indexer].key === null || observers[indexer].key === key){
	                observers[indexer].observer.observerKeyValueSet(key, value);
				}
            }
        }
    }

    this.addObserver = function(observer, key){
        observers.push({observer: observer, key: key});
    };

    this.removeObserver = function(observer){
        var ubounds = observers.length;
        var indexer = 0;
        for(indexer; indexer < ubounds - 1; indexer++){
            if(observer === observers[indexer]){
                observers.splice(indexer, 1);
                break;
            }
        }
    };

    this.set = function(key, value){
        notifySetObserversFor(key, value);
        me[key] = value;
    };

    this.get = function(key){
        return me[key];
    };

    if(options != null){
        for(prop in options){
            this.set(prop, options[prop]);
        }
    }
}