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