measureScrollbar = () => {
  const scrollDiv = document.createElement('div')
  scrollDiv.className = swalClasses['scrollbar-measure']
  document.body.appendChild(scrollDiv)
  const scrollbarWidth = scrollDiv.getBoundingClientRect().width - scrollDiv.clientWidth
  document.body.removeChild(scrollDiv)
  return scrollbarWidth
}
Measure scrollbar width for padding body during modal show/hide
https://github.com/twbs/bootstrap/blob/master/js/src/modal.js

@returns {number}