flutter - 如何在使用冻结创建的颤振模型类中接受不同数据类型的数据？

Question

我有一个自定义模型类Timestamp，其中我有一个构造函数，它接受对象DateTime并实例化Timestamp数据。

如何将此类转换为使用freezed？

class Timestamp {
  const Timestamp({
    required date,
    required time,
  }) {
    RegExp dateRegExp = RegExp(
      r'^\d{2}-\d{2}-\d{4}$',
    );
    assert(dateRegExp.hasMatch(date));
    RegExp timeRegExp = RegExp(
      r'^\d{2}:\d{2}:\d{2}$',
    );
    assert(dateRegExp.hasMatch(date));
    assert(timeRegExp.hasMatch(time));
    _date = date;
    _time = time;
  }

  Timestamp.fromDateTime({
    required DateTime dateTime,
  }) {
    _date = '${dateTime.day.toString().padLeft(2, '0')}'
        '-'
        '${dateTime.month.toString().padLeft(2, '0')}'
        '-'
        '${dateTime.year.toString().padLeft(2, '4')}';
    _time = '${dateTime.hour.toString().padLeft(2, '0')}'
        ':'
        '${dateTime.minute.toString().padLeft(2, '0')}'
        ':'
        '${dateTime.second.toString().padLeft(2, '0')}';
  }

  /// Format - 'dd-MM-yyyy'
  final String _date = '';

  /// Format - 'HH:mm:ss' (24 hour time)
  final String _time = '';

  String get date => _date;

  String get time => _time;

  DateTime toDateTime() {
    List<String> dateSubStrings = _date.split('-');
    List<String> timeSubStrings = _time.split(':');
    return DateTime.utc(
      int.parse(dateSubStrings[2]),
      int.parse(dateSubStrings[1]),
      int.parse(dateSubStrings[0]),
      int.parse(timeSubStrings[0]),
      int.parse(timeSubStrings[1]),
      int.parse(timeSubStrings[2]),
    );
  }

  // hashCode, toString, and equality methods
}