text: mwUI.Backbone.SelectableCollection = Backbone.SelectableCollection = Backbone.Collection.extend({
    selectable: true,
    selectableOptions: function(){
      return {
        isSingleSelection: false,
        addPreSelectedToCollection: false,
        unSelectOnRemove: false,
        preSelected: new Backbone.Collection()
      };
    },
    selectableCollectionConstructor: function(options){
      if (this.selectable) {
        this.selectable = new mwUI.Backbone.Selectable.Collection(this, this.selectableOptions.call(this,options));
      }
    },
    constructor: function (attributes, options) {
      var superConstructor = Backbone.Collection.prototype.constructor.call(this, attributes, options);
      this.selectableCollectionConstructor(options);
      return superConstructor;
    }
  });