@Override
  protected Object @NotNull [] buildChildren(@NotNull HierarchyNodeDescriptor descriptor) {
    final List<PyHierarchyNodeDescriptor> res = new ArrayList<>();
    final PsiElement element = descriptor.getPsiElement();
    if (element instanceof PyClass cls) {
      Query<PyClass> subClasses = PyClassInheritorsSearch.search(cls, false);
      for (PyClass subClass : subClasses) {
        res.add(new PyHierarchyNodeDescriptor(descriptor, subClass, false));
      }

    }

    return ArrayUtil.toObjectArray(res);
  }
@Override
  protected Object @NotNull [] buildChildren(@NotNull HierarchyNodeDescriptor descriptor)