backbonejs fetch prototype

combined.js

// fetch.js

    fetch: function fetch(options) {
      var deferred = $.Deferred();
      Backbone.Model.prototype.fetch.call(this, _.extend({ 
        deferred: deferred
        }, 
        options));
      return deferred;
    },


// fetchItem.js
    fetchItem: function fetchItem(itemSummary) {
      // this fetch is the code above on line 3
      this.item.fetch().done(_.bind(function() {
        this.renderItem(this.item);
      },this))
      .fail(function(error){
        // when GET fails like network issues, this won't show unlike native $.ajax fail where it will show the error
        console.log(error);
      });
    },

or
this.item.fetch().done(
    this.renderItem.bind(this, this.item)
);