code: public int getParent(int nodeHandle)
    {
  
      int identity = makeNodeIdentity(nodeHandle);
  
      if (identity > 0)
        return makeNodeHandle(_parent(identity));
      else
        return DTM.NULL;
    }
docs: Given a node handle, find its parent node.
  
  @param nodeHandle the id of the node.
  @return int Node-number of parent,
  or DTM.NULL to indicate none exists.