How to use the @ckeditor/ckeditor5-dev-utils.styles function in @ckeditor/ckeditor5-dev-utils

/**
 * @license Copyright (c) 2003-2020, CKSource - Frederico Knabben. All rights reserved.
 * For licensing, see LICENSE.md.
 */

'use strict';

const path = require( 'path' );
const escapedPathSep = path.sep == '/' ? '/' : '\\\\';
const { getPostCssConfig } = require( '@ckeditor/ckeditor5-dev-utils' ).styles;

/**
 * @param {Object} options
 * @returns {Object}
 */
module.exports = function getWebpackConfigForAutomatedTests( options ) {
	const config = {
		mode: 'development',

		module: {
			rules: [
				{
					// test: **/ckeditor5-*/theme/icons/*.svg
					test: /ckeditor5-[^/\\]+[/\\]theme[/\\]icons[/\\][^/\\]+\.svg$/,
					use: [ 'raw-loader' ]
				},

/**
 * @license Copyright (c) 2003-2020, CKSource - Frederico Knabben. All rights reserved.
 * For licensing, see LICENSE.md.
 */

'use strict';

const path = require( 'path' );
const WebpackNotifierPlugin = require( './webpacknotifierplugin' );
const { getPostCssConfig } = require( '@ckeditor/ckeditor5-dev-utils' ).styles;
const CKEditorWebpackPlugin = require( '@ckeditor/ckeditor5-dev-webpack-plugin' );

/**
 * @param {Object} options
 * @param {Object} options.entries
 * @param {String} options.buildDir
 * @param {String} options.themePath
 * @param {String} [options.language]
 * @param {Array.} [options.additionalLanguages]
 * @returns {Object}
 */
module.exports = function getWebpackConfigForManualTests( options ) {
	return {
		mode: 'development',

		// Use cheap source maps because Safari had problem with ES6 + inline source maps.

|
 | Mix provides a clean, fluent API for defining some Webpack build steps
 | for your Laravel application. By default, we are compiling the Sass
 | file for the application as well as bundling up all the JS files.
 |
 */

function assetsPath (dir = '') {
    return path.join(__dirname, './resources/assets/', dir)
}

function publicPath (dir = '') {
    return path.join(__dirname, './public/', dir)
}
const CKEditorWebpackPlugin = require('@ckeditor/ckeditor5-dev-webpack-plugin')
const CKEStyles = require('@ckeditor/ckeditor5-dev-utils').styles
const CKERegex = {
    svg: /ckeditor5-[^/\\]+[/\\]theme[/\\]icons[/\\][^/\\]+\.svg$/,
    css: /ckeditor5-[^/\\]+[/\\]theme[/\\].+\.css/
}

Mix.listen('configReady', webpackConfig => {
    const rules = webpackConfig.module.rules
    const targetSVG = /(\.(png|jpe?g|gif|webp)$|^((?!font).)*\.svg$)/
    const targetCSS = /\.css$/

    // exclude CKE regex from mix's default rules
    // if there's a better way to loop/change this, open to suggestions
    for (const rule of rules) {
        if (rule.test.toString() === targetSVG.toString()) {
            rule.exclude = CKERegex.svg
        } else if (rule.test.toString() === targetCSS.toString()) {