define(function(require,exports,module){    var Events=function(){        var array = [];        var push = array.push;        var slice = array.slice;        var splice = array.splice;        var Events  = {            // Bind an event to a `callback` function. Passing `"all"` will bind            // the callback to all events fired.            on: function(name, callback, context) {                if (!eventsApi(this, ‘on‘, name, [callback, context]) || !callback) return this;                this._events || (this._events = {});                var events = this._events[name] || (this._events[name] = []);                events.push({callback: callback, context: context, ctx: context || this});                return this;            },            // Bind an event to only be triggered a single time. After the first time            // the callback is invoked, it will be removed.            once: function(name, callback, context) {                if (!eventsApi(this, ‘once‘, name, [callback, context]) || !callback) return this;                var self = this;                var once = _.once(function() {                    self.off(name, once);                    callback.apply(this, arguments);                });                once._callback = callback;                return this.on(name, once, context);            },            // Remove one or many callbacks. If `context` is null, removes all            // callbacks with that function. If `callback` is null, removes all            // callbacks for the event. If `name` is null, removes all bound            // callbacks for all events.            off: function(name, callback, context) {                var retain, ev, events, names, i, l, j, k;                if (!this._events || !eventsApi(this, ‘off‘, name, [callback, context])) return this;                if (!name && !callback && !context) {                    this._events = {};                    return this;                }                names = name ? [name] : _.keys(this._events);                for (i = 0, l = names.length; i < l; i++) {                    name = names[i];                    if (events = this._events[name]) {                        this._events[name] = retain = [];                        if (callback || context) {                            for (j = 0, k = events.length; j < k; j++) {                                ev = events[j];                                if ((callback && callback !== ev.callback && callback !== ev.callback._callback) ||                                    (context && context !== ev.context)) {                                    retain.push(ev);                                }                            }                        }                        if (!retain.length) delete this._events[name];                    }                }                return this;            },            // Trigger one or many events, firing all bound callbacks. Callbacks are            // passed the same arguments as `trigger` is, apart from the event name            // (unless you‘re listening on `"all"`, which will cause your callback to            // receive the true name of the event as the first argument).            trigger: function(name) {                if (!this._events) return this;                var args = slice.call(arguments, 1);                if (!eventsApi(this, ‘trigger‘, name, args)) return this;                var events = this._events[name];                var allEvents = this._events.all;                if (events) triggerEvents(events, args);                if (allEvents) triggerEvents(allEvents, arguments);                return this;            },            // Tell this object to stop listening to either specific events ... or            // to every object it‘s currently listening to.            stopListening: function(obj, name, callback) {                var listeners = this._listeners;                if (!listeners) return this;                var deleteListener = !name && !callback;                if (typeof name === ‘object‘) callback = this;                if (obj) (listeners = {})[obj._listenerId] = obj;                for (var id in listeners) {                    listeners[id].off(name, callback, this);                    if (deleteListener) delete this._listeners[id];                }                return this;            }        };        // Regular expression used to split event strings.        var eventSplitter = /\s+/;        // Implement fancy features of the Events API such as multiple event        // names `"change blur"` and jQuery-style event maps `{change: action}`        // in terms of the existing API.        var eventsApi = function(obj, action, name, rest) {            if (!name) return true;            // Handle event maps.            if (typeof name === ‘object‘) {                for (var key in name) {                    obj[action].apply(obj, [key, name[key]].concat(rest));                }                return false;            }            // Handle space separated event names.            if (eventSplitter.test(name)) {                var names = name.split(eventSplitter);                for (var i = 0, l = names.length; i < l; i++) {                    obj[action].apply(obj, [names[i]].concat(rest));                }                return false;            }            return true;        };        // A difficult-to-believe, but optimized internal dispatch function for        // triggering events. Tries to keep the usual cases speedy (most internal        // Backbone events have 3 arguments).        var triggerEvents = function(events, args) {            var ev, i = -1, l = events.length, a1 = args[0], a2 = args[1], a3 = args[2];            switch (args.length) {                case 0: while (++i < l) (ev = events[i]).callback.call(ev.ctx); return;                case 1: while (++i < l) (ev = events[i]).callback.call(ev.ctx, a1); return;                case 2: while (++i < l) (ev = events[i]).callback.call(ev.ctx, a1, a2); return;                case 3: while (++i < l) (ev = events[i]).callback.call(ev.ctx, a1, a2, a3); return;                default: while (++i < l) (ev = events[i]).callback.apply(ev.ctx, args);            }        };        // Aliases for backwards compatibility.        Events.bind   = Events.on;        Events.unbind = Events.off;        return Events;    }()module.exports=Events})