Array.prototype.forEach.call(collapseButtons, collapseBtn => {
  collapseBtn.addEventListener('click', function (e) {
    const closestAccordion = collapseBtn.closest('.su-accordion');
    const closestBtns = closestAccordion.querySelectorAll('.su-accordion__button');
    Array.prototype.forEach.call(closestBtns, closestBtn => {