code: function(){
      var callbacks = this._callbacks;
      this._deferred = Marionette.$.Deferred();
      this._callbacks = [];
      
      _.each(callbacks, function(cb){
        this.add(cb.cb, cb.ctx);
      }, this);
    }
docs: Resets the list of callbacks to be run, allowing the same list to be run multiple times - whenever the `run` method is called.