/**
  * DOCUMENT ME!
  *
  * @return DOCUMENT ME!
  * @throws NoSuchElementException DOCUMENT ME!
  */
 public AttributeIterator next() throws NoSuchElementException {
   if (this.hasNext()) {
     attributeIterator.init(treeNodeIterator.next());
     return attributeIterator;
   } else {
     throw new NoSuchElementException();
   }
 }
 /**
  * DOCUMENT ME!
  *
  * @return DOCUMENT ME!
  */
 public boolean isDistinct() {
   return attributeIterator.isDistinct();
 }