@NotNull Set<TreePath> getExpandedPaths() {
      var result = new HashSet<TreePath>();
      var rootPath = getRootPath();
      if (!isRootVisible() || isExpanded(rootPath)) {
        result.add(rootPath);
      }
      for (Map.Entry<TreePath, Boolean> e : expandedState.entrySet()) {
        if (e.getValue()) {
          result.add(e.getKey());
        }
      }
      return result;
    }
@NotNull Set<TreePath> getExpandedPaths()