How to use the terra-toolkit/config/wdio/services.default-config.terraViewports function in terra-toolkit

import SERVICE_DEFAULTS from 'terra-toolkit/config/wdio/services.default-config';
import loadSiteConfig from '../../../scripts/generate-app-config/loadSiteConfig';
import generatePagesConfig from '../../../scripts/generate-app-config/generatePagesConfig';

const VIEWPORT_KEYS = process.env.FORM_FACTOR ? [process.env.FORM_FACTOR] : Object.keys(SERVICE_DEFAULTS.terraViewports);

const baseRouteOfExample = (siteConfig, pageKey) => {
  const baseRouteLink = siteConfig.navConfig.navigation.links.find(link => link.pageTypes.includes(pageKey));
  return baseRouteLink ? baseRouteLink.path : null;
};

const mergeObjectOfArrays = (object1, object2) => {
  const mergedObject = {};
  VIEWPORT_KEYS.forEach((key) => {
    mergedObject[key] = (object1[key] || []).concat(object2[key] || []);
  });
  return mergedObject;
};

const createViewportObjectFromPageTree = (pageKey, currentPage, currentRoute, options = {}) => {
  if (!currentPage.pages && options.testSetup.examples[currentPage.name]) {