function isFocusable(element) {
  // Elements that cannot be focused if they have [disabled] attribute.
  if (element[matchesFunc]('input, select, textarea, button, object')) {
    return element[matchesFunc](':not([disabled])');
  }

  // Elements that can be focused even if they have [disabled] attribute.
  return element[matchesFunc]('a[href], area[href], iframe, [tabindex], [contentEditable]');
}
@param {HTMLElement} element
@returns {boolean} Whether the element matches