Proxy or forward Backbone events through a mediator

backbone.events.extensions.js

(function() {

   var proxy = function(source, eventName) {
    var _self = this;
    source.on(eventName, function(evt) {
      var args = Array.prototype.slice.apply(arguments).splice(1);
      args.unshift(evt);
      _self.trigger.apply(_self, args);
    });
  };

  Backbone.View.prototype.proxyEvent = proxy;
  Backbone.Model.prototype.proxyEvent = proxy;
  Backbone.Collection.prototype.proxyEvent = proxy;
  Backbone.Router.prototype.proxyEvent = proxy;

  var forward = function(target, eventName) {
    var _self = this;
    _self.on(eventName, function(evt) {
      var args = Array.prototype.slice.apply(arguments).splice(1);
      args.unshift(evt);
      target.trigger.apply(target, args);
    });
  };

  Backbone.View.prototype.forwardEvent = forward;
  Backbone.Model.prototype.forwardEvent = forward;
  Backbone.Collection.prototype.forwardEvent = forward;
  Backbone.Router.prototype.forwardEvent = forward;

})();

Shouldn't line 7 and 21 be this?

args.unshift(eventName);

As is it's not forwarding the event.