How to use the pixi-viewport.Viewport function in pixi-viewport

constructor(options={})
    {
        super();
        this.options = Object.assign({}, scrollboxOptions, options);
        if (options.overflow) {
            this.options.overflowX = this.options.overflowY = options.overflow;
        }
        this.ease = typeof this.options.fadeScrollboxEase === 'function' ? this.options.fadeScrollboxEase : penner[this.options.fadeScrollboxEase];

        /**
         * content in placed in here
         * you can use any function from pixi-viewport on content to manually move the content (see https://davidfig.github.io/pixi-viewport/jsdoc/)
         * @type {Viewport}
         */
        this.content = this.addChild(new Viewport({ passiveWheel: this.options.passiveWheel, stopPropagation: this.options.stopPropagation, screenWidth: this.options.boxWidth, screenHeight: this.options.boxHeight }));
        this.content
            .decelerate()
            .on('moved', () => this._drawScrollbars());

        // needed to pull this out of viewportOptions because of pixi.js v4 support (which changed from PIXI.ticker.shared to PIXI.Ticker.shared...sigh)
        if (options.ticker)
        {
            this.options.ticker = options.ticker;
        }
        else
        {
            // to avoid Rollup transforming our import, save pixi namespace in a variable
            // from here: https://github.com/pixijs/pixi.js/issues/5757
            let ticker;
            const pixiNS = PIXI;
            if (parseInt(/^(\d+)\./.exec(VERSION)[1]) < 5)

constructor(options={})
    {
        super()
        this.options = Object.assign({}, scrollboxOptions, options)
        if (options.overflow) {
            this.options.overflowX = this.options.overflowY = options.overflow
        }
        this.ease = typeof this.options.fadeScrollboxEase === 'function' ? this.options.fadeScrollboxEase : Penner[this.options.fadeScrollboxEase]

        /**
         * content in placed in here
         * you can use any function from pixi-viewport on content to manually move the content (see https://davidfig.github.io/pixi-viewport/jsdoc/)
         * @type {Viewport}
         */
        this.content = this.addChild(new Viewport({ passiveWheel: this.options.passiveWheel, stopPropagation: this.options.stopPropagation, screenWidth: this.options.boxWidth, screenHeight: this.options.boxHeight }))
        this.content
            .decelerate()
            .on('moved', () => this._drawScrollbars())

        // needed to pull this out of viewportOptions because of pixi.js v4 support (which changed from PIXI.ticker.shared to PIXI.Ticker.shared...sigh)
        if (options.ticker)
        {
            this.options.ticker = options.ticker
        }
        else
        {
            // to avoid Rollup transforming our import, save pixi namespace in a variable
            // from here: https://github.com/pixijs/pixi.js/issues/5757
            let ticker
            const pixiNS = PIXI
            if (parseInt(/^(\d+)\./.exec(PIXI.VERSION)[1]) < 5)

onActionSend: any,
  ) {

    // App
    this.app = new Application({
      width: screenWidth,
      height: screenHeight,
      antialias: false,
      backgroundColor: utils.string2hex(Constants.BACKGROUND_COLOR),
    });

    // Map
    this.map = new Entities.Map(0, 0);

    // Viewport
    this.viewport = new Viewport({
      screenWidth,
      screenHeight,
    });
    this.app.stage.addChild(this.viewport);

    // Walls R-Tree
    this.walls = new Collisions.TreeCollider();

    // HUD
    this.hudManager = new HUDManager(
      screenWidth,
      screenHeight,
      utils.isMobile.any,
      false,
    );
    this.app.stage.addChild(this.hudManager);

throw `${parent} is not an element.`
		}

		this.socketManager.init(socket)

		const config = {
			width: window.innerWidth,
			height: window.innerHeight,
			resolution: window.devicePixelRatio || 1,
			resizeTo: window
		}

		PIXI.settings.SCALE_MODE = PIXI.SCALE_MODES.NEAREST
		PIXI.settings.ROUND_PIXELS = true

		this.viewport = new Viewport()
		this.application = new PIXI.Application(config)

		this.application.stage.addChild(this.viewport)

		this.viewport.drag({
			wheel: false,
			mouseButtons: 'left'
		})

		this.viewport.setZoom(5)

		this.cullManager.setViewport(this.viewport)

		this.resizeEvents()

		this.addDefaultRoom()