1. @override
Future<AuthClient> fetchClientByID(AuthServer server, String id)

Returns an AuthClient for a client ID.

This method must return an instance of AuthClient if one exists for clientID. Otherwise, it must return null. server is the AuthServer requesting the AuthClient.

Source 

@override
Future<AuthClient> fetchClientByID(AuthServer server, String id) async {
  var query = new Query<ManagedClient>(context)..where.id = id;

  var storage = await query.fetchOne();

  return storage?.asClient();
}