text: /**
   * 
   * http://requirejs.org/
   * 
   * @param {type} param
   */
  require.config({
      baseUrl: 'javascripts/',
      paths: {
          'jquery': 'vendor/jquery-2.1.1/jquery',
          'backbone': 'vendor/backbone-1.1.2/backbone',
          'underscore': 'vendor/underscore-1.6.0/underscore',
          'trackModel': 'library/trackModel',
          'tracksCollection': 'library/tracksCollection'
      }
      
  });
  
  require([
      'trackModel',
      'tracksCollection'
  ], function (TrackModel, TracksCollection) {
  
      'use strict';
  
      // tests
  
      var track = new TrackModel();
  
      var playlist = new TracksCollection();
  
      var history = new TracksCollection();
  
      console.log('playlist length before: ', playlist.length);
  
      playlist.add(track);
  
      console.log('playlist length after: ', playlist.length);
  
      console.log('history length before: ', history.length);
  
      history.add(track);
  
      console.log('history length after: ', history.length);
  
      //-----------------
      console.log('//-----------------');
  
      console.log('playlist length before: ', playlist.length);
      console.log('history length before: ', history.length);
  
      track.destroy();
  
      console.log('playlist length after: ', playlist.length);
      console.log('history length after: ', history.length);
      
  });