(function() {
	var topics = {};

	$.Topic = function( id ) {
	    var callbacks,
	        method,
	        topic = id && topics[ id ];
	    if ( !topic ) {
	        callbacks = $.Callbacks();
	        topic = {
	            publish: callbacks.fire,
	            subscribe: callbacks.add,
	            unsubscribe: callbacks.remove
	        };
	        if ( id ) {
	            topics[ id ] = topic;
	        }
	    }
	    return topic;
	};	
})();