text: define( [ 
      "backbone", 
      "../datum/Datum", 
      "recording/Recording",
      "recordings/Recordings"
  //    "../user/User"
  ], function(
      Backbone,
      Datum, 
      Recording, 
      Recordings
  //    User
      ) {
    var Exercise = Datum.extend(
     {
      /**
       * @class An Exercise is a type of Datum. It has the same information as a Datum plus extra,
       * but we want some info (e.g. recordings) to be kept confidential.
       *  
       * @property {String} timesListened This is number of times the whole AudioVideo has been listened to by a specific user
       * 
       * @property {Date} lastListened This is the date of the last time the student listened to this Exercise
       * 
       * @property {RecordArray} recordings This is the array of all the recordings made by the student
       * each recording will have an accuracyRating (a percentage saying how close to the student's recording is compared to the Datum's sound)
       * each recording will have privacy settings to be determined by the student
       * each recording will say who recorded it
       * each recording will say what date it was recorded
       * the RecordArray will tell us how many recordings it has in it.
       * 
       * @property {User} To be replaced by either student or teacher, but for the moment we just use User to get its ID.
  	 * maybe we don't need User because it'd be in Session, which is in Datum.
  	 * ? @property {String} student This is the ID of the student whose progress we're tracking
       * 
       * @extends Backbone.Model
       * 
       * @constructs
       * 
       */
      initialize : function() {
  //      Exercise.__super__.initialize.call(this,);
  
  //      this.set("user", "");
        this.set("lastListened", new Date(JSON.parse(t)));
        this.set("timesListened", "");
        //make the array of recordings
        
      },
      
      internalModels : {
        // recordAudio  :  RecordAudio
        // compareAudio  :  CompareAudio
      },
      saveAndInterConnectInApp : function(callback){
        
        if(typeof callback == "function"){
          callback();
        }
      }
    });
  
    return Exercise;
  }); 
  
  
  
  