DeleterDataSource<Type, Param> class abstract

Implement this abstract in your data source if it can perform data deletion. Note that 1 class can implements from multiple abstracts.

class SessionDataSource implements DeleterDataSource<Unit, Unit> {
  final HttpClient client;

  const SessionDataSource({required this.client});

  /// Use unit to represent void
  @override
  FutureOr<Unit> delete({Unit params = unit}) async {
    /// Perform sign out
  }
}

Instead of throwing an exception, you should return Left instead.

P.S. Signing out means deleting session. Therefore, deleter data source.