public void restore() {
   final UsageNode node = myUsageNodes.get(myUsage);
   if (node == NULL_NODE || node == null) {
     return;
   }
   final DefaultMutableTreeNode parentGroupingNode = (DefaultMutableTreeNode) node.getParent();
   if (parentGroupingNode != null) {
     final TreePath treePath = new TreePath(parentGroupingNode.getPath());
     myTree.expandPath(treePath);
     if (mySelected) {
       myTree.addSelectionPath(treePath.pathByAddingChild(node));
     }
   }
 }
 private void restoreUsageExpandState(final Collection<UsageState> states) {
   // always expand the last level group
   final DefaultMutableTreeNode root = (DefaultMutableTreeNode) myTree.getModel().getRoot();
   for (int i = root.getChildCount() - 1; i >= 0; i--) {
     final DefaultMutableTreeNode child = (DefaultMutableTreeNode) root.getChildAt(i);
     if (child instanceof GroupNode) {
       final TreePath treePath = new TreePath(child.getPath());
       myTree.expandPath(treePath);
     }
   }
   myTree.getSelectionModel().clearSelection();
   for (final UsageState usageState : states) {
     usageState.restore();
   }
 }