@Nullable
  public static DebuggerTreeNodeImpl getSelectedNode(DataContext dataContext) {
    DebuggerTree tree = getTree(dataContext);
    if (tree == null) return null;

    if (tree.getSelectionCount() != 1) {
      return null;
    }
    TreePath path = tree.getSelectionPath();
    if (path == null) {
      return null;
    }
    Object component = path.getLastPathComponent();
    if (!(component instanceof DebuggerTreeNodeImpl)) {
      return null;
    }
    return (DebuggerTreeNodeImpl)component;
  }
@Nullable
  public static DebuggerTreeNodeImpl getSelectedNode(DataContext dataContext)