code: public static <T> List<T> toRoot(TreeDef.Parented<T> treeDef, T node) {
  		List<T> list = new ArrayList<>();
  		T tip = node;
  		while (tip != null) {
  			list.add(tip);
  			tip = treeDef.parentOf(tip);
  		}
  		return list;
  	}
docs: Creates a mutable list whose first element is {@code node}, and last element is its root parent.