How to use the @jupyter-widgets/controls.DescriptionView.prototype function in @jupyter-widgets/controls

initialize: function (parameters) {
    DescriptionView.prototype.initialize.apply(this, arguments);

    this.icons = this.model.get("icons");
    // Be sure to work on deep copy, otherwise object will be updated and
    // model.set will not find any differences and nothing will be sent to python!
    this.states = clone(this.model.get("state"));
    this.treeModel = this.toModel(this.model.get("tree"));

    this.listenTo(this.model, "change:state", () => this.updateAllStates());
  },