// Web browser engine (WebCore)
// Written in JavaScript 
 
// Define the global variables and functions needed by the engine 
var document; // DOM document object 
var window;   // Window object to hold global variables 
var console;  // Console object for logging messages to the browser console 
  
// Define a function to create a new HTML element with given tag name and attributes  
function createElement(tagName, attrs) { 

    // Create an element with the given tag name                              var elem = document.createElement(tagName);

    // Set all of the provided attributes on the element                      for (let attr in attrs) {      elem.setAttribute(attr, attrs[attr]);     }

    return elem;     }

     // Define a function that parses an HTML string into DOM nodes   function parseHTML(htmlString) {      return new DOMParser().parseFromString(htmlString, "text/html");     }

      // Define a function that takes an HTML string and appends it to a parent node   function appendHTML(parentNode, htmlString) {       let domNodes = parseHTML(htmlString).body.childNodes;        for (let i=0; i < domNodes.length; i++) {           parentNode.appendChild(domNodes[i]);        }     }

       // Define a function that takes an URL and fetches its content as text or HTML   async function fetchURLAsTextOrHTML(url) {       let response = await fetch(url);       let contentType = response.headers.get("content-type");        if (contentType && contentType.includes("text/html")) {           return await response.text();        } else {            return await response.json();         }    }