code: function getPreviousSiblings(el, siblings = []) {
      const previousSibling = el.previousSibling;
  
      if (!previousSibling) {
          return siblings;
      }
  
      siblings.push(previousSibling);
  
      return getPreviousSiblings(previousSibling, siblings);
  }
docs: recursive function to get previous sibling nodes of given element