@Override
 public boolean hasNext() {
   return m_tree.hasNext();
 }
 @Override
 public DataPoint next() {
   return m_tree.nextElement();
 }
 public void addIterator(DataPointGroup taggedDataPoints) {
   m_tree.addIterator(taggedDataPoints);
   addTags(taggedDataPoints);
   m_taggedDataPointsList.add(taggedDataPoints);
 }