public static @NotNull String write(@NotNull Parent element, String lineSeparator) {
    try {
      StringWriter writer = new StringWriter();
      write(element, writer, lineSeparator);
      return writer.toString();
    }
    catch (IOException e) {
      throw new UncheckedIOException(e);
    }
  }
public static @NotNull String write(@NotNull Parent element, String lineSeparator)