How to use the vott-ct/lib/js/CanvasTools/Core/Rect.Rect function in vott-ct

private onSelectionEnd = (regionData: RegionData) => {
        if (CanvasHelpers.isEmpty(regionData)) {
            return;
        }
        const id = shortid.generate();

        this.editor.RM.addRegion(id, regionData, null);

        this.template = new Rect(regionData.width, regionData.height);

        // RegionData not serializable so need to extract data
        const scaledRegionData = this.editor.scaleRegionToSourceSize(
            regionData,
            this.state.currentAsset.asset.size.width,
            this.state.currentAsset.asset.size.height,
        );
        const lockedTags = this.props.lockedTags;
        const newRegion = {
            id,
            type: this.editorModeToType(this.props.editorMode),
            tags: lockedTags || [],
            boundingBox: {
                height: scaledRegionData.height,
                width: scaledRegionData.width,
                left: scaledRegionData.x,

project: null,
        lockedTags: [],
    };

    public editor: Editor;

    public state: ICanvasState = {
        currentAsset: this.props.selectedAsset,
        contentSource: null,
        enabled: false,
    };

    private canvasZone: React.RefObject = React.createRef();
    private clearConfirm: React.RefObject = React.createRef();

    private template: Rect = new Rect(20, 20);

    public componentDidMount = () => {
        const sz = document.getElementById("editor-zone") as HTMLDivElement;
        this.editor = new CanvasTools.Editor(sz);
        this.editor.autoResize = false;
        this.editor.onSelectionEnd = this.onSelectionEnd;
        this.editor.onRegionMoveEnd = this.onRegionMoveEnd;
        this.editor.onRegionDelete = this.onRegionDelete;
        this.editor.onRegionSelected = this.onRegionSelected;
        this.editor.AS.setSelectionMode({ mode: this.props.selectionMode });

        window.addEventListener("resize", this.onWindowResize);
    }

    public componentWillUnmount() {
        window.removeEventListener("resize", this.onWindowResize);