Method init

src/component/timeline/TimelineModel.ts:187–190

* @override

(option: TimelineOption, parentModel: Model, ecModel: GlobalModel)

     * @override
     */
    init(option: TimelineOption, parentModel: Model, ecModel: GlobalModel) {
        this.mergeDefaultAndTheme(option, ecModel);
        this._initData();
    }

    /**
     * @override