unregister method
Implementation
@override
Future<EchoResponse> unregister({
required String projectId,
required String clientId,
}) async {
final url = Uri.parse('$baseUrl/$projectId/clients/$clientId');
final http.Response response =
await httpClient.delete(url, headers: headers);
final jsonMap = json.decode(response.body);
return EchoResponse.fromJson(jsonMap);
}