private @Nullable Object extractSelectedNodeNavigatable() {
    TreePath selectedPath = TreeUtil.getSelectedPathIfOne(myTree);
    if (selectedPath == null) return null;
    DefaultMutableTreeNode node = ObjectUtils.tryCast(selectedPath.getLastPathComponent(), DefaultMutableTreeNode.class);
    if (node == null) return null;
    ExecutionNode executionNode = ObjectUtils.tryCast(node.getUserObject(), ExecutionNode.class);
    if (executionNode == null) return null;
    List<Navigatable> navigatables = executionNode.getNavigatables();
    if (navigatables.size() != 1) return null;
    return navigatables.get(0);
  }
private @Nullable Object extractSelectedNodeNavigatable()