@Override
  public @NotNull List<FoldingBuilder> allForLanguage(@NotNull Language language) {
    for (Language l = language; l != null; l = l.getBaseLanguage()) {
      List<FoldingBuilder> extensions = forKey(l);
      if (!extensions.isEmpty()) {
        return extensions;
      }
    }
    return Collections.emptyList();
  }
@Override
  public @NotNull List<FoldingBuilder> allForLanguage(@NotNull Language language)