liveOnce extension to backbrace.js's live function

gistfile1.txt

(function() {
  var liveOnceExtension = {
      liveOnce: function(selectors, callback, context) {
          var _this = this;
          var wrapper = function() {
              _this.die(selectors, wrapper, context);
              callback.apply(this, arguments);
          }
          this.live(selectors, wrapper, context);
      }
  };
  _.extend(Backbone.Model.prototype, liveOnceExtension);
  _.extend(Backbone.Collection.prototype, liveOnceExtension);
}());