public DefaultMutableTreeNode getNextNode() { return null; }
public DefaultMutableTreeNode getNextNode() {  if (getChildCount() != 0) return (DefaultMutableTreeNode) getChildAt(0);   DefaultMutableTreeNode node = this; DefaultMutableTreeNode sibling;  do { sibling = node.getNextSibling(); node = (DefaultMutableTreeNode) node.getParent(); } while (sibling == null && node != null);   return sibling; }
	public DefaultMutableTreeNode getNextNode() {		return null; // TODO	} // getNextNode()