JSFiddle - React, Tailwind, and code Playground

HTML

<script src="https://cdn.ckeditor.com/4.4.7/standard/ckeditor.js"></script>
<input type="radio" name="done" value="foo">
 <input type="radio" name="done" value="bar">

JavaScript

var foo = CKEDITOR.document.findOne( 'input[value="foo"]' );
 var bar = CKEDITOR.document.findOne( 'input[value="bar"]' );

 window.setTimeout( function() {
         foo.setAttribute( 'checked', true );
 }, 1000 );

 window.setTimeout( function() {
         bar.setAttribute( 'checked', true );
 }, 2000 );

 window.setTimeout( function() {
         // It won't work.
         foo.setAttribute( 'checked', true );
 }, 3000 );