getClient method
Must return 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.
Implementation
@override
Future<AuthClient?> getClient(AuthServer server, String clientID) async {
final query = Query<ManagedAuthClient>(context)
..where((o) => o.id).equalTo(clientID);
final storage = await query.fetchOne();
return storage?.asClient();
}