public static void writeCustomField(@NotNull Element parent, @NotNull String tagName, @Nullable String value) {
    Element element = new Element(tagName);
    if (value != null) {
      element.setAttribute(Constants.VALUE, value);
    }
    parent.addContent(element);
  }
public static void writeCustomField(@NotNull Element parent, @NotNull String tagName, @Nullable String value)