https://www.wrrb.org/wp-content/plugins/responsive-embeds-pro/assets/responsive-embeds.js?ver=2.1.0

1/* Responsive Embeds Pro - External JS */
2(function(){
3  "use strict";
4  function onloadSetup(){
5    document.querySelectorAll(".resp-embed .resp-iframe").forEach(function(iframe){
6      iframe.addEventListener("load", function(){
7        var wrapper = this.closest(".resp-embed");
8        if (wrapper) { wrapper.classList.remove("loading"); wrapper.classList.add("loaded"); }
9      }, { once: true });
10    });
11  }
12  if (document.readyState === "loading") document.addEventListener("DOMContentLoaded", onloadSetup);
13  else onloadSetup();
14
15  if (window.MutationObserver) {
16    var observer = new MutationObserver(function(muts){
17      muts.forEach(function(m){
18        if (m.type === "childList") {
19          m.addedNodes.forEach(function(n){
20            if (n.nodeType === 1) {
21              var iframes = n.querySelectorAll ? n.querySelectorAll("iframe") : [];
22              if (iframes.length) onloadSetup();
23            }
24          });
25        }
26      });
27    });
28    observer.observe(document.body, { childList:true, subtree:true });
29  }
30})();