typedef를 사용하는이유?

이전 강의까지는 상위 class에 method를 생성해서 onTap() 함수를 넘겨줬는데 이번엔 전역으로 typedef로 선언한 이유가 있을까요?

typedef ColorIdSetter = void Function(int id);

class _ColorPicker extends StatelessWidget {
  const _ColorPicker({
    super.key,
    required this.colors,
    required this.selectedColorId,
    required this.colorIdSetter,
  });
  final List<CategoryColor> colors;
  final int selectedColorId;
  final ColorIdSetter colorIdSetter;

  @override
  Widget build(BuildContext context) {
    return Wrap(
      runSpacing: 10,
      spacing: 8,
      children: colors
          .map(
            (e) => GestureDetector(
              onTap: () {
                colorIdSetter(e.id);
              },
              child: renderColor(e, selectedColorId == e.id),
            ),
          )
          .toList(),
    );
  }

/// Signature of callbacks that have no arguments and return no data.
typedef VoidCallback = void Function();