How to use the @hpcc-js/other.Comms.ESPUrl function in @hpcc-js/other

Marshaller.prototype.url = function (url, callback) {
    this.espUrl = new Comms.ESPUrl()
        .url(url)
        ;
    let transport = null;
    let hipieResultName = "HIPIE_DDL";
    if (this.espUrl.isWorkunitResult()) {
        hipieResultName = this.espUrl.param("ResultName");
        transport = new Comms.HIPIEWorkunit()
            .url(url)
            .proxyMappings(this._proxyMappings)
            .timeout(this._timeout)
            ;
    } else {
        transport = new Comms.HIPIERoxie()
            .url(url)
            .proxyMappings(this._proxyMappings)
            .timeout(this._timeout)

init(placeholder: string, urlStr, layoutJson?) {
        const _url = new Comms.ESPUrl().url(urlStr);
        if (!!_url.param("dashboard")) {
            this._dashy = new Dashboard(new ElementContainer())
                .target(placeholder)
                .hideSingleTabs(true)
                .titleVisible(false)
                .render()
                ;
        } else {
            this._dashy = new Dashy()
                .target(placeholder)
                .render()
                ;
        }

        this._dashy.element()
            .on("drop", () => this.dropHandler(this.event()))

import { DDLEditor, JSEditor, JSONEditor } from "@hpcc-js/codemirror";
import { d3SelectionType, HTMLWidget } from "@hpcc-js/common";
import { Result } from "@hpcc-js/comms";
import { ddl2Schema, upgrade } from "@hpcc-js/ddl-shim";
import { Dashboard, ElementContainer } from "@hpcc-js/marshaller";
import { Comms } from "@hpcc-js/other";
import { DockPanel, SplitPanel } from "@hpcc-js/phosphor";
import { scopedLogger } from "@hpcc-js/util";

const logger = scopedLogger("app");

export class App extends DockPanel {
    private _url = new Comms.ESPUrl().url(document.URL);
    private _ddlv1 = new JSONEditor();
    private _ddlv2_upgraded = new JSONEditor();
    private _elementContainer: ElementContainer = new ElementContainer();
    private _dashboard = new Dashboard(this._elementContainer);
    private _ddlv2 = new JSONEditor();
    private _schema = new JSONEditor();

    constructor() {
        super();
        this.parseParams();
        this._schema.json(ddl2Schema);
    }

    parseParams() {
        if (this._url.param("Wuid")) {
            const baseUrl = `${this._url.param("Protocol")}://${this._url.param("Hostname")}:${this._url.param("Port")}`;