get method
Retrieves the value mapped to key, or null if no mapping
exists. Implementations may also throw a backend-specific
not-found exception (e.g. KeyNotFoundException) instead of
returning null — consult the concrete impl.
Implementation
@override
Future<AtNotification?> get(String key) async {
final rows = _db.raw
.select('SELECT payload FROM notifications WHERE id = ?;', [key]);
if (rows.isEmpty) return null;
return SqliteNotificationCodec.decode(rows.first['payload'] as String);
}