code: function() {
      var aSelectedRows = [];
      var tracker = this._aSelections || [];
      for(var j=0; j<tracker.length; j++) {
         if(lang.isString(tracker[j])){
              aSelectedRows.push(tracker[j]);
          }
      }
      return aSelectedRows;
  }
docs: Returns selected rows as an array of Record IDs.
  
  @method getSelectedRows
  @return {String[]} Array of selected rows by Record ID.