class Node { // May not be a real situation for a Node class, // but makes a point. Node getLeft() { return left; }

class Node { // May not be a real situation for a Node class, // but makes a point. Node getLeft() { return left; } } // No more checks against NULL. In fact code becomes simpler for // the user of the library. node.getLeft().getLeft().getValue(); I don't think the class definition is much too complicated, except for the declaration of the EMPTY field. What we need is a non-mutable, class-wide, default object, not null. We don't need to explicitly declare this object, if the language does that for us and make it accessible through a keyword - say 'default': if (n.left != default) { traverse(n.left); }