 </h2>
<section aria-labelledby="toc_polyfill">
<p>This is a concept that typically means providing JavaScript which tests for features that are missing (prototypes not defined, etc) and "fills" them by providing an implementation.</p>
</section>
<h2 id="toc_promise">Promise <a href="#toc_promise"><svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 512 512">
        <path d="M326.61 185.4c59.75 59.8 58.93 155.69.36 214.58-.1.12-.24.25-.36.37l-67.2 67.2c-59.27 59.27-155.7 59.26-214.96 0-59.27-59.26-59.27-15