extension MapExt<K, V> on Map<K, V> {
  T? getCheck<T>(K? key) {
    if (key == null || !containsKey(key)) {
      return null;
    }
    var value = this[key];
    if (value is! T) {
      return null;
    }
    return value as T?;
  }
}

extension StringExt on String? {
  bool get isNullOrEmpty {
    return this == null || this!.isEmpty;
  }
}

extension ListExt<T> on List<T>? {
  bool get isNullOrEmpty {
    return this == null || this!.isEmpty;
  }
}

extension DateTimeExt on DateTime {
  String get yyyyMMddHHmmss =>
      "$year-${month < 10 ? "$month".padLeft(2, "0") : month}-$day ${hour < 10 ? "$hour".padLeft(2, "0") : hour}:${minute < 10 ? "$minute".padLeft(2, "0") : minute}:${second < 10 ? "$second".padLeft(2, "0") : second}";
}