https://oliviachristensensalon.com/wp-content/plugins/strx-magic-floating-sidebar-maker/js/debounce.js

1//http://unscriptable.com/index.php/2009/03/20/debouncing-javascript-methods/
2Function.prototype.debounce = function (threshold, execAsap) {
3    var func = this, // reference to original function
4        timeout; // handle to setTimeout async task (detection period)
5    // return the new debounced function which executes the original function only once
6    // until the detection period expires
7    return function debounced () {
8        var obj = this, // reference to original context object
9            args = arguments; // arguments at execution time
10        // this is the detection function. it will be executed if/when the threshold expires
11        function delayed () {
12            // if we're executing at the end of the detection period
13            if (!execAsap)
14                func.apply(obj, args); // execute now
15            // clear timeout handle
16            timeout = null; 
17        };
18        // stop any current detection period
19        if (timeout)
20            clearTimeout(timeout);
21        // otherwise, if we're not already waiting and we're executing at the beginning of the detection period
22        else if (execAsap)
23            func.apply(obj, args); // execute now
24        // reset the detection period
25        timeout = setTimeout(delayed, threshold || 100); 
26    };
27};