How to extend

let config = {
    "config": {
        "mixins": {
            "TechDivision_EnhancedMenu/js/enhanced-menu": {
                "AngelaBruderer_Menu/js/extended-enhanced-menu": true
            }
        }
    }
};

define([
    'jquery',
], function ($) {
    'use strict';

    return function (widget) {
        $.widget('techdivision.enhancedMenu', widget, {
            options: {
                here it is possible to overwrite options with new values
            },
            mobileMode: function () {
                this._super();

// this extends the mobileMode function with a new on click event for mobile
                let widget = this;
                // close trigger for mobile menu section
                this.options.navClose.on('click.mobile touchstart.mobile', function (e) {
                    widget.options.navSection.removeClass('opened');
                    widget.disableMenuBgLayer();
                    widget.mobileToggleBodyScroll();
                    e.preventDefault();
                });
            }
        });
        // noinspection JSUnresolvedVariable
        return $.techdivision.enhancedMenu;
    }
});