@Override
    public @Nullable Object getParentElement(@NotNull Object element) {
      if (element == RootDescriptor.ROOT) {
        return null;
      }
      else if (element instanceof String) {
        return RootDescriptor.ROOT;
      }
      return ((CertificateWrapper)element).getSubjectField(ORGANIZATION);
    }
@Override
    public @Nullable Object getParentElement(@NotNull Object element)