/**

* Specifies a function to execute when the DOM is fully loaded.

* @param {function} fn - A function to execute after the DOM is ready.

* @see https://learn.jquery.com/using-jquery-core/document-ready/

* @see http://youmightnotneedjquery.com/#ready

* @see https://developer.mozilla.org/en-US/docs/Web/Events/DOMContentLoaded

* @see https://caniuse.com/#feat=domcontentloaded

*/

function ready (fn) {

if (document.attachEvent ? document.readyState === 'complete' : document.readyState !== 'loading') {

fn()

} else {

document.addEventListener('DOMContentLoaded', fn)

}

}