build method

Implementation

@override
String build() {
  final Iterable<Element> thisChildren = [
    ...children,
    if (autoLink && id != null)
      A(
        classes: [autoLinkClass],
        href: "#${id!}",
        children: [autoLinkElement],
      ),
  ];
  return "<h$level$modifiers>"
      '${thisChildren.map((el) => el.build()).join("\n")}'
      "</h$level>";
}