https://www.googlecloudpresscorner.com/js/webdriver.js

1// Global webDriver object/namespace to contain spin-specific variables and methods.
2// May be extended by some spin features.
3// MUST be included immediately after including spin's version of jQuery.
4
5(function(window, undefined) {
6	if (window.webDriver)
7		return;
8	
9	var webDriver = {};
10
11	// Save our version of jQuery and restore any previously loaded version
12	webDriver.jQuery = jQuery.noConflict(true);
13	
14	// If there was no previously loaded version of jQuery, make ours active
15	// These could still be overridden later
16	if (!window.jQuery)
17		window.jQuery = webDriver.jQuery;
18	if (!window.$)
19		window.$ = webDriver.jQuery;
20
21	// Methods to switch to/from our version of jQuery
22	var jQueryDepth = 0;
23	var prevJQuery = null;
24	var prevDollar = null;
25
26	webDriver.push_jQuery = function() {
27		if (jQueryDepth == 0) {
28			prevJQuery = jQuery;
29			prevDollar = $;
30			jQuery = $ = this.jQuery;
31		}
32
33		jQueryDepth++;
34	};
35
36	webDriver.pop_jQuery = function() {
37		jQueryDepth--;
38
39		if (jQueryDepth == 0) {
40			window.jQuery = prevJQuery;
41			window.$ = prevDollar;
42		}
43	};
44	
45	// Make the webDriver object accessible
46	window.webDriver = webDriver;
47})(window);