saveButton method Null safety

Widget saveButton(
  1. Future<void> savePressed(
      )?
    )

    A dialogue 'Save' button which executes savePressed when pressed.

    Implementation

    static Widget saveButton(Future<void> Function()? savePressed) {
  return TextButton(
    onPressed: savePressed == null
        ? null
        : () async {
            await savePressed();
          },
    child: const Text('Save'),
    style: ButtonStyle(
      foregroundColor: MaterialStateProperty.all(Colors.black),
    ),
  );
}