vanilla js add multiple attributes

setattributes.js

var el = document.querySelector('.button');

function setAttributes(el, attrs) {
    Object.keys(attrs).forEach(key => el.setAttribute(key, attrs[key]));
}

setAttributes(el, { 
  class: 'button button--lg button--inverted', 
  'data-src': 'https://player.vimeo.com/video/28629415?autoplay=false', 
  'data-padding-bottom': '56.25%', 
  href: 'javascript:void(0);' 
});