Snipped of a model where we add timing code around an xhr

model-fetch.js

  ...
  fetch: function(){
    var url = this.get('url');
    var self = this;
    //start the timer
    App.startTimer('dataset-fetch', 'ajax', 'Dataset: ' + this.get('id'));
    //closure for the callback
    var doneCB= function(data){
      self.loadFromJson(data);
      //stop the timer
      App.stopTimer('dataset-fetch');
    };
    //make the call (via App) tack on the callback
    var jqXhr = App.getJSON(url).done(doneCB);
    //return the promise
    return jqXhr;
  },
  ...