code: public int getLastChild(int nodeHandle) {
                  // ###shs put trace/debug later
                  nodeHandle &= NODEHANDLE_MASK;
                  // do not need to test node type since getFirstChild does that
                  int lastChild = NULL;
                  for (int nextkid = getFirstChild(nodeHandle); nextkid != NULL;
                                  nextkid = getNextSibling(nextkid)) {
                          lastChild = nextkid;
                  }
                  return lastChild | m_docHandle;
          }
docs: Given a node handle, advance to its last child.
  If not yet resolved, waits for more nodes to be added to the document and
  tries again.
  
  @param nodeHandle int Handle of the node.
  @return int Node-number of last child,
  or DTM.NULL to indicate none exists.