util.js
function previousSiblings(element) {
  var prev = element.previousSibling;
  var siblings = [];

  while (prev) {
    siblings.push(prev);
    prev = prev.previousSibling;
  }

  return siblings;
}
function previousSiblings(element) {
  var prev = element.previousSibling;
  var siblings = [];

  while (prev) {
    siblings.push(prev);
    prev = prev.previousSibling;
  }

  return siblings;
}
function previousSiblings ( element ) { var prev = element . previousSibling ; var siblings = [ ] ; while ( prev ) { siblings . push ( prev ) ; prev = prev . previousSibling ; } return siblings ; }
Return all prev siblings
@param  {Element} element
@return {Array.<element>}
Return all prev siblings