NestedSet - Traversing a tree _nonrecursively_

Hello I need to implement a Iterator-class for a NestedSet. Since there should be a methode next() that gives me the values of a node, I have to traverse the tree _nonrecursively_ . My idea was to program a helper class Stack that would help me implementing my nonrecursiv iterator. I am not sure if this is a good solution. Any hints for a performant algorithm are welcome! Thanks! -- cu Marco