How to use the sketch-constructor.Page function in sketch-constructor

import { Sketch, Page, Artboard, Text, Rectangle } from 'sketch-constructor';
import * as sketchJson from 'sketch-json';
import * as fs from 'fs';

const pkg = JSON.parse(fs.readFileSync('./package.json', 'utf8'));
const buildFolder = './build';

const newSketch = new Sketch({});
const pageWelcome = new Page({
  name: 'Welcome'
});

let yPos = 0;

const addYPos = (value: number = 0) => {
  return yPos = yPos + value;
}

const textVersion = new Text({
  string: `Version: ${pkg.version}`,
  name: `Version: ${pkg.version}`,
  fontSize: 16,
  color: "#777",
  frame: {
    x: 1058,

function buildFlows(designInfo, newSketch) {
    for (const flow of designInfo.flows) {
        const page = new Page({
            name: flow.flowName
        });

        if (flow.interactions == null) {
            continue;
        }

        var index = 1;
        for (const interaction of flow.interactions) {
            let seeComponentName = interaction.see.componentName.replace(/\"/g, "");
            let seeComponentData = interaction.see.data.replace(/\"/g, "");
            const artboard = new Artboard({
                name: seeComponentData + seeComponentName,
                frame: {
                    width: '320px',
                    height: '480px',

function buildLibrary(designInfo, newSketch) {
    const libraryPage = new Page({
        name: "Library"
    });

    var offset = 20;
    var lastX = 20;
    for (const library of designInfo.libraries) {
        const artboard = new Artboard({
            name: library.libraryName
        });

        switch (library.libraryName) {
            case "Color":
                buildColorLibrary(library.libraryPresets, newSketch, artboard);
                break;
            case "FontSize":
                buildFontSizeLibrary(library.libraryPresets, newSketch, artboard);